91社区

Drawing good quality digital figures and writing exercises for the class notes, MECH 315, Mechanical Vibrations, for mechanical engineers.

Drawing good quality digital figures and writing exercises for the class notes, MECH 315, Mechanical Vibrations, for mechanical engineers.

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Metal fuels in the form of powders have the potential to create a closed-loop, net zero-carbon energy commodity cycle. Indeed, the combustion of metal particles in a reactor results in the formation of metal oxides, harmless products that can be captured, reduced to their metallic form, and reused as fuels. To design and optimize industrial metal burners, several fundamental questions which are key to our understanding of the complex physics underlying metal particle combustion must be resolved. In particular, the ignition phenomenon of solid fuel particles leads to a burning regime exhibiting rapid reaction kinetics and high energy release rates. Metal burners with ignited particles therefore present the potential for practical, high-power applications, motivating the need to accurately predict this phenomenon. The proposed research project aims to develop a computational model to theoretically simulate the generic unsteady ignition process of metal particles. Numerical simulations based on the model will provide insight regarding feasible conditions under which this process can occur. Please contact Jan Palecka (jan.palecka [at] mail.mcgill.ca) to apply for this position.

Develop models for ignition and combustion of metal particles. Assist with experiments on burning metal particles and droplets.

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According to the United Nation's Paris Agreement, there is a pressing need to limit the increase in global average temperature to 2 潞C above pre-industrial levels. Among a multitude of long-term solutions, the replacement of internal combustion engines in vehicles by electric motors will inevitably play an important role. All-solid-state lithium batteries (ASSLBs) have recently emerged as a promising alternative for next-generation EVs, because ASSLBs can overcome the intrinsic disadvantages presented by the flammable liquid electrolytes (LEs) used in traditional LIBs by replacing the LEs with a solid-state electrolyte to minimize the concern and achieve greater energy density and longer lifespan. While ASSLBs are compelling, one of the grand challenges is to solve the stability issue between the electrodes (cathode and anode) and the solid-state-electrolyte (SSE). In this project, the student will develop an environmental cell that can host solid-state battery materials under an atomic force microscopy for operando investigations of the stability issues in ASSLBs. The project requires solid background in mechanical design and instrumentation. Materials knowledge is not the focus.

Design the environmental cell Fabricate the environmental cell Perform proof-of-concept experiment using the cell Write an SOP for the development

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Lower back pain and spinal disorders are one of the leading causes of workplace absences and medical consultations, causing significant economic burden on developed nations. Within the Musculoskeletal Biomechanics Research Lab at 91社区, many elaborate finite element models of the spine are being developed to evaluate spinal stability and guide the understanding of spinal stresses and strains. These models may provide key information regarding irregular load sharing in low back pain patients. However, these models require validation through clinical data to ensure accuracy within the results obtained.

From a clinical perspective, one essential method of understanding and evaluating back pain is by studying spinal curvature. A non-invasive imaging modality, such as MRI, can provide clear visualization of normal and pathological spine anatomy, which can be used to analyse the alignment of the spine. As such, MRIs or X-rays taken of the thoracic and lumbar spine in the sagittal plane of healthy subjects and low back pain patients can be used to investigate the differences in spinal curvature between these two subject groups through the measurement of the Cobb angle. Consequently, a retrospective study will be conducted in which a finite element model of the thoracolumbar spine will aim to distinguish between healthy and back pain patients. Thus, the role of this year鈥檚 SURE student will be to gather data of spine alignment from MRI or X-ray images using the program OsiriX MD, in conjunction with the developed finite element model, in order to classify patients as exhibiting healthy or unhealthy lordotic and kyphotic curvature.

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Four in five Canadians will develop low back pain (LBP) some time in their lives 鈥� and 85-90% of those afflicted will never know the root cause of their pain. One known potential cause may be lack of control of intra-abdominal pressure (IAP), or the pressure contained within the abdominal cavity. This is conventionally also refered to as, or analogous to, core strength. Abnormal IAPs have been linked to LBP and spinal instability as shown by several research groups. BioOpticTM is a novel device of the Musculoskeletal Biomechanics Research Lab at 91社区 that is accurate and non-invasive. This novelty is protected via apparatus and method patent applications now in PCT phase (CA2021050696). Further, this approach has been shown effective in two- clinical trials thus far.

A second iteration of the test device will be developed and finalized over the summer. Technical drawings and production will take place to have a functional prototype in hand while working with a graduate student from the lab. Next, field studies are required to judge the usability and further validate the device. This will build on the above-mentioned validity studies performed thus far on human and cadavers. Specifically, field studies will be conducted in physical therapy clinics and sport performance training centers. This will be conducted under the currently approved and extended IRB Study Number A12-M63-19A (19-12-043). i) To begin a Human Factor Engineering (HFE) and Usability Engineering (UE) plan will be produced. ii) Then a formative round of testing will be conducted with our various collaborators such as physical therapist, health practitioners, and athletic trainer participation. Student will assist in administering this process of the new device.

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Vehicles that are able to autonomously move in the air, on the ground, or underwater must fuse various forms of sensor data together in order to ascertain the vehicles precise location relative to objects. This process is called navigation. Typical sensor data includes inertial measurement unit (IMU) data, and some sort of range data from an optical camera or time of flight sensor (e.g., ultra wide band radio, LIDAR). The SURE student(s) will focus on sensor fusion for the purposes of robot navigation. Specifically, the student(s) will likely work on one of the following sub-projects: monocular camera based navigation for ground robots, navigation using a magnetic field map for a team of ground and/or aerial robots, marine robot navigation, autonomous train navigation. Students best fit for this position are those interested in using kinematics/dynamics, linear algebra, probability theory, and numerical methods, to solve real-world problems found in robotics. Comfort with python/matlab/C++ programming is desired. Depending on the student's interest and/or experience, the students may work more with data and hardware, or more with theory. Year 2 and 3 students will be considered (that is, students who have taken MECH 309 or equivalent.)

- Formulate and solve the research problem (with assistance from Prof. Forbes and DECAR systems group members). - Write code to test the algorithm in a simulation. - Test using simulation and/or experimental data (if available).

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The motion of dense particle clouds accelerated with a shock wave is poorly understood, particularly the role of particle-particle interactions on the relative motion of the particles. To probe the physics of the two-phase flow, we are developing a gauge that detects the arrival of a particle at a given location based on the use of a triboluminescent powder, i.e., a material that emits a flash of light when impacted. The light is collected and recorded with a photomultiplier tube. The project involves calibrating and testing our prototype gauge using a high-speed flow of particles. The particles will be accelerated by placing a layer of particles at the exit of a shock tube. Analysis of the light output of the gauge will be used to determine the rate of particle impacts.

The existing triboluminescent gauge will be first be calibrated by impacting the gauge surface with a single particle moving at a known speed. This will be followed by the construction of a shock tube for accelerating a layer of particles. Analysis of the gauge output will be carried out to infer the rate of arrival of particles at the gauge location.

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Fine metal powder can burn at high temperature to provide a carbon-free energy source for propulsion and power generation applications. While considerable information is available about the combustion of single metal particles in quiescent conditions, the effect of ambient flow on the combustion characteristics, including the particle burn time, particle temperature, and the existence of a critical flow velocity for combustion extinction, is poorly understood. We are developing an apparatus to study the effect of flow on metal particle combustion. The apparatus consists of a mechanism to feed a metal wire and a spark discharge to melt and ignite a metal droplet, together with an optical system to observe the droplet. Most of the apparatus components are available, but the apparatus must be assembled and tested before systematic experiments on metal combustion can be carried out. Please contact Jake Boening (jake.boening [at] mail.mcgill.ca) to apply for this position.

The experimental components must be assembled and tested to determine the operating parameters of the system, including the wire diameter and material, feeding rate, spark discharge properties, and so on. Some work is needed to finalize the design of the spark discharge system as well as the system for generating gas flow. The ability of the system to generate and ignite metal droplets will be determined as a function of system parameters and observed with the high-magnification optical system.

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Directed energy via laser beam is an effective way of overcoming the limitations of conventional aerospace propulsion by "leaving the power source at home." This project explores two approaches to laser propulsion: laser thermal rockets and photon pressure lightsails. In laser thermal propulsion, a laser beam from Earth is used to heat a propellant that is expanded through a nozzle to generate thrust. This technology is well-suited for missions in the solar system. For a lightsail, the reflection of laser photons from the sail imparts momentum on the sail. The laser lightsail approach has the potential to achieve true interstellar flight. This project examines the fundamental interactions of lasers with matter, either hydrogen propellant or the laser lightsail. The issues of radiative transport, nonequilibrium product expansion, and photon reflection between reflective surfaces will be studied both theoretically and experimentally.

Student 1 will set up an apparatus with a pulsed laser to experimentally examine laser-matter interaction. This will include designing safety enclosures, target chamber, and associated diagnostics. Student 2 will conduct modelling on laser absorption in gases (hydrogen) and the subsequent nonequilibrium expansion of the gas. Effects of radiative transport and finite rate chemistry will be examined via one-dimensional and two-dimensional modelling. Student 3 will engage the problem of photon reflection and assess the feasibility of photon 鈥渞ecycling.鈥� Experimental work will include using the existing photonic Doppler velocimetry (PDV) apparatus at 91社区 to examine the dynamics of lightsails.

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The energy necessary for interstellar flight is the primary challenge for sending spacecraft to other solar systems. Recently, the concept of tapping into sources of energy available in space, in particular, the flow of charged particles that comprise the solar wind, has been considered. The ability of electromagnetic fields to interact with the tenuous flow of charged particles over enormous distances has the potential to tap into this source of energy for propulsive purposes. One approach will consider the relative motion of a magnetic structures generated by driving currents through the space plasma (the so-called Plasma Magnet) to generate high energy charged particles. A related approach will examine how to concentrate the energy of the solar wind into a coherent beam that would be capable of acting as an directed energy source. Finally, this project will consider some engineering requirements of these concepts, which typically involved deploying superconducting cables, so the radiative cooling and dynamics of electromagnetically supported cables will be considered. While the work with be predominately theoretical and modelling, simple experiments were be performed at 91社区 and in field experiments to demonstrate the operating principles and to explore engineering implementations.

Student 1 will perform simulations of charged particles interacting with the relative motion of a magnetic dipole to explore the maximum energy that can be achieved. Student 2 will examine how interactions with the solar wind can be used to drive charged particle beams that鈥攊n turn鈥攎ay be used to accelerate a spacecraft. Student 3 will work on the practical implementation of some engineering aspects of these concepts including potential field experiments to examine radiative cooling and deployment of superconducting cables.

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While thermoset polymer matrix carbon fibre composites are widespread in the industry, thermoplastic composites(TPC鈥檚) are rapidly becoming increasingly popular due to their increased usage as observed in recent trends. Thermoplastic polymers can be melted, remelted, and reformed. In addition, TPC鈥檚 have short processing times, and they have the potential to be recycled and repaired, making them excellent sustainable materials. In addition, TPC鈥檚 have higher fracture toughness, better strength-to-weight ratios, and superior impact resistance and fatigue performance when compared to their metallic and thermoset composite counterparts. Currently, there is no viable method to repair aircraft structures made with thermoplastic composites as there are challenges associated with the current repair techniques used on thermoset polymer composite structures. Fusion bonding, in particular induction, resistance, and ultrasonic welding have been identified as potential techniques for repair. To fully take advantage of TPC鈥檚 on aircraft structures and to be able to certify them, it is key to develop a systematic methodology for repair.

a) Performing experiments in the effort to develop process maps for thermoplastic composite repair b) Assisting with the manufacturing and testing composite substrates joined using a fusion bonding technique or a combination of the most promising methods (i.e., induction, resistance, and ultrasonic welding)

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Graphene is a 2D sp2 hybridized network of carbon atoms that was first discovered in 2004 at the University of Manchester [1]. It has since then seen an ever-growing interest from industry principally due to its incredible intrinsic properties with an elastic modulus up to 1TPa and an electrical conductivity of 108 S/m [2] [3]. Consequently, the use of such material as a filler in composite materials has impressive effects on the mechanical and electrical properties of the part. There is, however, still many challenges in order to have commercial applications of such systems. The dispersion of the particles and their interactions with the resin system are key parameters to understand and optimize the properties system. The dispersion is usually measured in term of dispersion index that is obtained by optical microscopy followed by an automated image analysis [4]. The interaction between the particles and the media are measured in term of a zeta potential obtained by Dynamic Light Scattering (DLS). In this project, we propose to investigate the interactions between graphene and two thermosetting system, as well as the resulting effects on the electrical and mechanical properties.

The work will include the following tasks: - Prepare the samples to measure the zeta potential of graphene in different media. - Investigate the effect of different surfactant compositions on the zeta potential. - Investigate the effect of different surfactant on the dispersion index. - Select composition of interest and produce composite samples by compression molding. - Measure electrical conductivity and mechanical properties of the produced plates.

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The printability of FFF filaments is a concept that depends on the polymeric material behavior and type of the 3D printer. As indicated earlier, this characteristic can be quantified by measuring the toughness of filament using a texture analyzer. In this method which is also known as Repka-Zhang test, a threshold value is found for toughness of FFF filaments in a way that any filament demonstrating toughness above that value can be considered printable. This threshold is different for different 3D-printers [4]. There are several other mechanical properties that might be related to printability of FFF filaments and can be measured by more common equipment such as tensile testing machine which is more available in mechanical laboratories than a texture analyzer. This project aims to study the mechanical properties of different FFF filaments such as tensile strength, tensile modulus, flexural modulus, toughness, and stiffness in order to investigate the possible relationship between those properties and the printability of the FFF filaments. The mentioned properties will be measured using MTS testing machines located in Structures and Composite Materials Laboratory. The characterized filaments will be fed into AON 3D-printer in order to evaluate their printability and investigate its possible association with measured mechanical properties.

Specifically, the following tasks should be fulfilled for this project: 鈥� Brief review of available literature on FFF 3D printing and printability of FFF filaments 鈥� Learn how to use AON 3D-printer 鈥� Learn how to use MTS testing machine and its different fixtures 鈥� Build a test plan for mechanical testing of filaments 鈥� Perform mechanical tests (tensile test, compression test, 3-points bending test) on different filaments and interpret the results 鈥� Calculate the mechanical properties such as toughness and stiffness using the mechanical tests results

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Additive manufacturing (AM) alias 3D printing is emerging as an enabling technology and predicted to revolutionize the fabrication of the materials. Fused filament fabrication (FFF) is one of the most utilized AM techniques due to its ability to manufacture simple to complex geometries, customizations, rapid prototyping and less costly compared to other AM techniques. Nevertheless, FFF exhibit some limitations such as poor interlaminar adhesion that led to shrinkage which finally affects the mechanical properties of the materials. To improve the interlayer adhesion in the 3D printed parts, additives can be added. The aim of this work to study and understand the behaviour of 3D printed parts. In this study low concentration of nanomaterials such as carbon nanotubes (CNT), graphene (GP) and halloysite nanotubes (HNT) will be added using spray technique. Various polymer systems will be explored including polyetherimide (PEI), polyphenylene sulfide (PPS), and polyamide (PA). Moisture analysis, porosity test and contact angle tests will be performed to observe the properties of the coated filament that will be used for the printing. Furthermore, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), tensile testing will be employed to test the thermo-mechanical properties of the printed part.

Step 1: Literature review on the topic Step 2: Prepare a suspension of nanomaterials (CNT, GP, HNT) in water and or organic solvents Step 3: Apply this dispersed suspension of nanomaterials (0.1, 0.5 and 1 wt%) onto the surface of the commercial filaments using spray technique Step 4: Dry these nanomaterials coated filament in the oven Step 5: Characterize the properties of the coated filaments: porosity, moisture test, contact angle Step 6: Use these filaments to print tensile samples by 3D printer and optimize the print parameters Step 7: Test the mechanical and thermal properties of the printed dog-bone samples by tensile test and DMTA, DSC, TGA Step 8: Compile all the results and write a short report

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Compression Moulding of Carbon Fibre Sheet Moulding Compounds is a highly efficient way to produce high performance composite parts in quick succession. The moulds required for this process must withstand extreme forces and high temperatures during compression and thus constitute sizable initial investments for every part to be produced. Join us in experimentally investigating the process itself, and its effect on the quality of the moulded composite samples. You will be making samples and characterize the SMC compound while closely monitoring the processing data. The quality of the samples will be measured by microscopy.

鈥� Validate overall the Compression Moulding process to produce parts free of major defects 鈥� Monitor and evaluate the temperature uniformity during processing 鈥� Inspect the quality of the moulded samples 鈥� Investigate the mechanical properties of the moulded samples

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Electric-powered aircraft are becoming increasingly popular in the aviation community due to modern sustainability awareness. Compared to traditional combustion engines, electric motors allow more flexibility to position the propulsors and have better integration of propulsion system to the airframe. It also enables the development of new aircraft concepts such as eS/VTOL which utilizes the distributed electric propulsion (DEP) configuration. In this project, impact of the DEP propeller, mounted at the tip of a rectangular semi-wing model, on the tip vortex flow at different ground distances will be investigated in the J. Bombardier wind tunnel in the Aerodynamics Laboratory in the Department of Mechanical Engineering. Special emphasis will be placed on the propeller slipstream on the change in the induced drag and the characteristics of the tip vortex. For qualitative study, a small wing model will also be constructed and tested in a small water tunnel facility. Dye flow visualization will be performed to better understand the overall behavior of the tip vortex flow structure and propeller-wing interaction at selected angles of attack and propeller rotations. In addition to the experimental measurements, the SURE student is also expected to participate heavily in the design and 3D construction of the wing models.

Design of wing models and conduct some measurements

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Differential equations are ubiquitous in engineering applications. In particular, they are used as models in elastodynamics. A wide range of techniques exist to solve them including finite element, finite volume, and discontinuous Galerkin schemes. These techniques perform very well for a wide range of problems. It is now clear that Machine Learning techniques are also able to cope with differential equations by creating models to approximate the relationship between two sets of data (inputs and outputs). A subset of machine learning techniques involves what are called Neural Networks in which a model is set up with adjustable parameters that are tuned such that the model fits a desired behaviour. The objective of this research project is to apply this method to the solution of differential equations, and time dependent problems in particular , with a focus on periodic solutions, known to be of high importance in vibration analysis of mechanical systems.

The main objective of the project is to use existing Jupyter notebooks investigating the use of Neural Networks for solving Partial Differential Equations and available on the net and to adapt them to the investigation of the dynamics of simplified and possibly nonlinear oscillators.

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Composite Materials such as Fiberglass are not easily recycled. There is a project underway to develop methods of recycling composites into materials that will be used in 3D printing. The fibers improve the properties of the 3D printing material, however, the recycled fibers complicate the printing process. Through characterization and experimenting with the process, a sustainable recycling method is to be developed.

Master one of the labs 3D printers. Learn the recycling method for composites. Learn the reinforced filament making process for input into 3D printers Life cycle analysis Produce recycled parts

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Aneurysms are balloon-like bulges of an artery wall and are associated with a weakening of the structure of the artery. Intercranial aneurysms are located deep within the arteries of the brain and are highly susceptible to rupture, resulting in high morbidity and mortality. Successful treatment of ruptured and unruptured aneurysms is crucial in preventing the dire consequences of these events. The most common treatment is through endovascular embolization of the aneurysm. Thin platinum coils are delivered by a micro-catheter and packed into the aneurysm sac. Once inside, the coils slow the flow of blood within the aneurysm and induce clotting which embolizes the aneurysm. Although generally an effective technique, endovascular coiling has some deficiencies that can limit its effectiveness. Wide-necked aneurysms can allow for coils to migrate or unravel from the aneurysm into the parent artery, increasing the risk for aneurysm re-growth and rupture or stroke. Furthermore, incomplete filling of the aneurysm can lead to coil compaction and subsequent aneurysm recurrence. This project aims to improve current coil designs by using bioactive coatings to increase coil packing densities and induce clotting within the aneurysm sac. Additionally, adhesion between the bioactive coating and the arterial wall will help to form a more stable occlusion, further preventing coil migration and compaction. The performance of this device will be validated by in vitro studies using vascular models to simulate endovascular treatment of an aneurysm.

Device fabrication, mechanical testing, material synthesis, in vitro model development, validation

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Presence of space debris has become a serious problem for safe operation of satellites. Hence, it is necessary to remove these space objects and transfer them to a graveyard orbit or to the upper atmosphere so that they can get burnt there. Several methods can be used to capture space debris. After capture, the debris can be towed using a space tug to the required altitude. There are many dynamics and control issues associated with optimal towing of space debris. This project will study these issues and investigate methods to minimize the fuel expenditure for debris removal.

The student will develop a mathematical model to describe the orbital and attitude dynamics associated with space debris towing. This will be followed by computer simulation of the system dynamics. Optimal control of the orbital transfer will then be carried out. The work will involve analytical as well as computational tools such as Matlab.

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The project consists in exposing immortalized human vocal fold fibroblast cells encapsulated in porous scaffold materials to various regimen of ultrasonic excitation and evaluate the effects of high frequency stresses and strains on their viability, motility, and biological response.

Student 1 will work on the transduction aspects and design a generator and actuator to isonify the cells. The second student will evaluate the sound field in the scaffold and the specific acoustic attenuation of the scaffold medium. The third student will measure the expression of key genes and as well as the level of various cytokines in the medium.

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A new material with elastic properties and fracture toughness similar to soft oral mucosa will be investigated, called PHEMA. The new material is porous, with mechanical fracture, permeability and diffusion properties that better mimic human soft tissues that gelatin.

The student will prepare material carrots, perform torsional rheometry and traction tests, and perform tests on an existing test bench.

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Hot-wire anemometers and cold-wire thermometers are devices employed to (most commonly) measure the velocity and temperature fields of turbulent flows. Their strength lies in their i) high temporal resolution, ii) high spatial resolution, and iii) good signal-to-noise ratio. However, commercial hot-wire anemometry systems are produced by only 3 companies and can be excessively expensive (>$30K). Moreover, modern designs suffer from a certain failing, which leads to increased drift (see: Hewes et al., 2020. Drift compensation in thermal anemometry, Measurement Science and Technology 31 (4), 045302). The proposed project involves the design and construction of a custom-built hot-wire anemometer and (time permitting) a complementary cold-wire thermometry system, followed by its benchmarking / testing in the 91社区 Aerodynamics Laboratory. If successful, commercialization is possible, given that there exists a need for high-performance / low-cost anemometry and thermometry systems.

1) Become familiar with the theory underlying hot-wire anemometry and cold-wire thermometry, including the necessary electronics. 2) Lean how to make hot-wire anemometry and cold-wire thermometry measurements. 3) Undertake a literature review of hot-wire anemometry and cold-wire thermometry circuits in the literature. 4) Propose a refined design to improve their performance. 5) Build prototype(s). 6) Benchmark prototypes against commercially available systems. 7) If successful, perform a market analysis with the possible aim of commercialization. 8) Prepare a report summarizing the student's activities.

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As the effects of climate change increasingly impact the lives of people across the globe, the need for accurate models of climate prediction is crucial. From the Canadian perspective, melting of perennial snowfields and glaciers are causing the country to warm two to three times faster than the remainder of the world. Moreover, our melting ice caps, which drain to the Arctic ocean, hold the greatest potential contribution to global sea level rise from Canadian territory. To better predict the melting of perennial snowfields and glaciers, improved models of the turbulent heat transfer between the (turbulent) atmospheric wind and snow/ice surfaces are required. To this end, the proposed research will serve to improve our understanding of the heat transfer between air and snow/ice, by way of wind-tunnel experiments undertaken in the 91社区 Aerodynamics Laboratory. In this laboratory, a wind tunnel with a novel 鈥渁ctive grid鈥� will be used to emulate atmospheric wind conditions. Effects of snow density, wind speed, and turbulence intensity of the wind on the heat transfer rates will be investigated.

1) Learn about the fundamentals of turbulent heat transfer, focusing on that over surfaces undergoing phase change. 2) Become familiar with the wind tunnel and other equipment to be used in the experiments (e.g. hot-wire anemometer, thermocouples, data acquisition system, etc.). 3) Design and build an apparatus to insert snow and ice into the wind tunnel. 4) Benchmark the flow in the wind tunnel. 5) Undertake experiments that quantify the dependence of the heat transfer on the snow density, wind speed (Reynolds number), and turbulence intensity of the flow. 6) Prepare a report summarizing the student's activities.

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The ability of turbulence to mix one or more scalars (e.g. temperature, chemical species concentration, etc.) within a fluid is of particular relevance to a variety of engineering applications (e.g. heat transfer, combustion, environmental pollution dispersion). In general, the turbulent mixing process stretches and stirs the scalar field, which serves to increase the scalar gradients. The scalar fluctuations are then smoothed out by the molecular mixing that principally occurs at the smallest scales of the turbulence. However, our comprehension and ability to predict turbulent mixing are limited because the fluid mechanics that govern turbulent mixing involve multi-scale phenomena for which the details are not yet fully understood, due the complex, nonlinear and chaotic nature of turbulent flows. The objective of the proposed work is to improve our understanding of the turbulent scalar mixing process in internal flows (e.g. pipes, ducts and channels). To this end, direct numerical simulations will be undertaken to simulate the full range of scales in turbulent flows without resorting to any turbulent models. They will be undertaken using a code entitled 3DFLUX (Germaine et al., 2013. 3DFLUX: A high-order fully three-dimensional flux integral solver for the scalar transport equation, Journal of Computational Physics 240, pp. 121-144). The simulations will focus in the effect of the injection method of the scalar on its subsequent mixing in the channel.

1) Become familiar with the fundamentals of turbulent flow and scalar mixing therein. 2) Learn about the code being used, the platform on which the simulations will be undertaken, and post-processing tools. 3) Undertake some fundamental, smaller (low-Reynolds-number) simulations to benchmark the code and data analysis / post-processing techniques. 4) Once validated, undertake simulations in which the scalar is injected in different manners, to investigate the dependence of the scalar mixing on its initial conditions. 5) Prepare a report summarizing the student's activities.

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There is no shortage of natural or engineering processes in which two fluids mix. These include the confluence of two rivers, fuel and oxidizer mixing in any combustion system, a smokestack emitting a pollutant into the atmosphere, or a sneeze/cough propagating in a room. To quantify the mixing of the two fluids, one must be able to measure the concentration of one fluid in the other. However, to fully understand the mixing process itself (so that the mixing of the fluids can be predicted and/or improved), one must be able to simultaneously measure the velocity and concentration of one fluid as it mixes with the other. Moreover, given that i) the vast majority of flows are turbulent, and ii) turbulent flows are characterized by a large range of time and length scales (which are regularly sub-millisecond and sub-millimeter), high-resolution measurement techniques are required. My research group has developed a technique to simultaneously measure velocity and concentration of a gas (e.g. helium) at high resolution (Hewes and Mydlarski, 2021. Design of thermal-anemometry-based probes for the simultaneous measurement of velocity and gas concentration in turbulent flows. Measurement Science and Technology, vol. 32 (10), 105305). However, we believe that the approach can be both optimized and simplified by way of some modifications. To this end, the current project will aim to further improve and simplify this measurement technique. Having done so, it will be tested by studying a jet emitted into a co-flow, which is typical of many turbulent mixing processes.

1) Become familiar with the theory underlying hot-wire anemometry and related measurement equipment. 2) Become familiar with the fundamentals of turbulent flow and mixing therein. 3) Learn how to fabricate a hot-wire anemometry sensor. 4) Propose a refined design to both simplify and improve the performance of the measurement technique. 5) Validate the new measurement technique by making measurements in the turbulent channel flow facility of a jet emitted into a confined co-flow. 6) Prepare a report summarizing the student's activities.

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Design of aerodynamic surfaces using high-fidelity approaches have typically been demonstrated through gradient-based optimization techniques for their lower computational cost but these approaches can only guarantee local optimum solutions. Traditional artificial intelligence using genetic algorithms and/or surrogate modeling based neural-network techniques have not been able to compete non only in terms of the lower computational cost of gradient-based techniques but these approaches have not been able to realize global optimum solutions that are superior to gradient-based approaches. Both approaches have been employed and compared within the computational aerodynamic design community for a series of benchmark aerodynamic design cases in the past with inconclusive results. The objective of this summer research project is to revisit this research problem and systematically establish a comprehensive comparison between the approaches.

The summer students will employ common approaches in neural network techniques and couple the code to our in-house computational aerodynamics analysis and design code. The student will then compare the approaches for a standard series of benchmark problems and identify their strengths and weaknesses. Student 1. The student will develop a low-order nonlinear model based on model-reduction approaches to provide functional values. Student 2. The student will extend the current POD-Galerkin approach, and investigate adaptive methods to improve the accuracy of functionals such as lift and drag.

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The Aerospace Mechatronics Laboratory houses a wide range of unmanned aerial vehicles, including airships, quadrotors, gliders, fixed-wing and hybrid aircraft. The overall objective of our research is to develop platforms for a range of tasks. Example applications include gliders for wildfire monitoring and fixed-wing aircraft for autonomous acrobatic flight through obstacle fields. Two SURE students are sought with strong interest and aptitude for research in the areas of robotics, mechatronics and aerial systems. One of the positions will be oriented toward design and modeling of small indoor airships. The second position will focus more on the modeling and control of fixed-wing UAVs. Some experimental testing of components and associated flight tests will be involved, particularly for the second position. In addition, the students will be involved with interfacing new sensors into the platforms, for the purposes of acquiring data and for closed loop control. Some programming experience would be useful for the development of a real-time hardware-in-the-loop simulation. The students are expected to assist with hardware interfacing, programming, conducting experiments, and processing the data.

The tasks will be varied and could accommodate mechanical, electrical or software engineering students; but ideally someone with experience in all aspects. The first position will be best served by a student with knowledge of CAD modeling and Matlab/Simulink and/or other physics-based modeling tools such as Gazebo and ROS. The second position will be best served by a student with knowledge of interfacing of sensing hardware with microprocessors; and programming. Both students will be involved in experimental testing in the field.

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Nuclear Fusion has the potential to deliver clean, safe and abundant electrical power on an industrial scale. Industrial fusion however remains elusive, due to the extreme conditions required involving temperatures of hundreds of degrees Celsius. In a concept called Magnetized Target Fusion (MTF), plasma is compressed to fusion conditions using a collapsing cavity of liquid metal. The liquid is spun by a rotor to form a cylindrical cavity which is collapsed by injecting fluid through channels in the rotor walls. 1) As fluid is ejected from the channels, irreversible viscous losses occur which limit the speed of the compression process and ultimately the temperatures and pressures which can be achieved. It is critical to characterise these losses to inform rotor designs of future MTF machines. 2) Once compression happens, pressure waves cause cavitation to occur, which need to be understood.

1) The student will develop experimental hardware and measurement techniques, including unsteady pressure measurements and optical diagnostic techniques. The student will also develop data analysis procedures. A key challenge will be scaling the results from the lab conditions to the operating conditions of the real MTF machine (U1/U2 level). 2) The resultant wave activity and fluid cavitation will be monitored via piezoelectric pressure transducers and direct visualization of liquid interfaces via high-speed videography through a glass window. The experimental results will be validated with the development of a quasi-one-dimensional model of fluid motion and wave-tracking of acoustic waves (U3 level)

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The increasing growth and popularity of multirotor vehicles has similarly seen an increase in the breadth and scope of their applications. In particular, the need to fly these vehicles near surfaces, or in the wake of other vehicles, has led to new challenges in predicting the performance of the vehicle/propeller. The project will explore some of these challenges.

Project is broad in scope, so the applicant will have the opportunity to develop their own research plan. In general, tasks include: 1) Develop analytical model to account for change in propeller performance for given condition 2) Verify model against experimental data collected in the lab

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Turbulent separated flows are a common feature in many engineering problems. Examples of turbulent separations include the wake behind a car body or the flow in the corner of a bladerow in a jet engine. Turbulent separations in many real applications exhibit a bizarre chaotic behaviour in which the size or shape of the separation changes drastically over timescales many hundreds of times longer than any turbulent eddy in the flow. Until recently, the mechanism has been poorly understood. Recent progress has provided an explanation for behaviour in the simple case of a turbulent wake behind an obstacle. The aim of this project is to extend this understanding to more complex flows in industrial problems. This will be approached using a novel experiment which will bridge the gap between the simplified case of the wake behind and obstacle, and internal flows such as those found in jet engines.

The student will help develop the novel experiment. This will involve the design of experimental hardware and the installation of aerodynamic instrumentation.

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The student will be trained by the PI in carrying out experimental testing of foldable paper-based metamaterials responding to mechanical input and temperature variation. Involvement in the fabrication aspects of cm-scale prototypes will also part of the training. The student will learn how to use laser cutting and other 3D printing technologies. He will be exposed to mechanical and thermal testing of samples tested in a controlled environment. Training of digital image correlation will be given to assess deformation.

Fabrication and testing of paper-based origami materials

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Internal damping forces are present in soft materials ranging from rubber to biotissues. The combination of these damping forces with elastic forces is know as viscoelasticity. Soft robots could leverage their viscoelasticity to be more effective in bioengineering applications such as implants, surgery, and wearable robotic devices: they might match damping and elastic characteristics of the user to provide better placement or more precise control. Yet, it is often difficult to synthesize materials with desired viscoelastic parameters. This project will investigate how to build meta-materials with tunable elasticity and damping by adhering and patterning existing materials together. You will investigate adhesives for meta-material synthesis, perform physical characterization experiments, and gain exposure to modelling techniques in solid mechanics. This project is jointly advised with Prof. Jianyu Li.

a) Investigate adhesives and bioadhesives for meta-material synthesis through a literature review and a suite of adhesion experiments. b) Physically characterize resulting meta-materials using known test standard from solid mechanics. c) Devise an application-informed design methodology for design of viscoelastic meta-materials in soft robotic, biomedical, or wearable applications.

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Unlike traditional robots, soft robots can take a variety of unusual 3D shapes. However, it is challenging to estimate the shape of a soft robot while it operates, which makes precise control difficult. This project is inspired by Mark Kac鈥檚 question, 鈥淐an one hear the shape of a drum?鈥� (Short answer: not all the time, due to the existence of isospectral manifolds.) The work will analytically investigate 3D extensions of this problem and experimentally investigate fusion of acoustic sensing with other modes (e.g., cameras) to estimate the 3D shape of soft robots as they operate. You will analyze acoustics and dynamics, build a variety of soft robot prototypes, develop sensing frameworks, and evaluate their performance. Two positions are available -- one for a more analysis-inclined student, and one for an experimentalist.

1. a) Gain exposure to differential geometry concepts useful in dynamics b) Perform analysis investigating vibrations of in a 3D space (such as the inside of a soft, inflatable robot!) c) Together with other student, work with experimental data to derive insight relevant to design and control of soft robots 2. a) Gain exposure to applied electronics concepts including circuit prototyping and sensor fusion. b) Perform experiments measuring acoustic sensor output under various soft robot states c) Together with other student, work with experimental data to derive insight relevant to design and control of soft robots

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Soft, compliant robots exhibit morphological intelligence. By conforming with their surroundings, they are able to operate in safe and effective ways without complicated control systems. Pressurized air is an ideal way to actuate such soft robots, because it can take the same shape as its surroundings. Yet, air can require large tubes and bulky pressure regulation equipment, resulting in soft robots that are limited by heavy tethers. This project proposes to build sequences into soft robot behavior by including 鈥減inch points,鈥� which limit air flow, in the design. You will analyze the effect of these pinch points on air flow into a soft robot, validate this analysis on experimental data, and build a morphologically intelligent soft robot demonstration. This project will involve data analysis, physics, and fabrication.

1) Analyze soft, sequential robot data to gain design insight 2) Gain exposure to soft robot design literature 3) Develop design methodology for soft, sequential robots 4) Develop application-informed soft robot prototype using design methodology

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Professor Sharf is working with FPInnovations on increasing robotics and automation in tree harvesting machinery. These are large and powerful mobile manipulators. Several projects are being worked on by her graduate students. As part of this research, we have developed a simulator in Vortex Studio which enables a user to operate the machine through a game pad, in a reasonably realistic simulation environment. We would like to make a number of improvements to the simulator, such as: introducing sensors on the machine, integration with ROS, integration with VR set. We also plan to conduct some experimental testing on the log loader facility at FPInnovations. The student would work on providing assistance in working with this facility and in carrying out tests. Although the student will be primarily involved in the work related to the mobile manipulator systems, we may require the student to also help out with flight testing of some of our quadrotor platforms.

1) Assist with improving Vortex simulator of feller-buncher and forward machines. 2) Assist with setting up experiments on log-loader facility at FPInnovations 3) Assist with flight testing

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Harnessing the Sun鈥檚 energy into a renewable, low-carbon heat source for power generation is the basis of solar thermal energy technologies. Concentrated solar power (CSP) plants use mirrors to concentrate natural sunlight hundreds to thousands of times, producing excess thermal energy during the day that can be stored at low-cost, and used during night-time operation to dispatch electricity 24/7. The Thermal Energy Laboratory is currently developing a low cost molten salt solar receiver using specially developed engineered concrete materials. This work will involve developing various concrete mixtures, manufacturing concrete solar receivers/storage tanks, conducting various thermophysical property measurements, and testing the receivers with high temperature molten salts mixtures under the Thermal Energy Lab鈥檚 6.5kW solar simulator facility. This project is ideal for students interested in renewable energy and experimental heat transfer.

(1) Developing various concrete mixtures, (2) manufacturing concrete solar receivers/storage tanks, (3) conducting various thermophysical property measurements, and (4) testing the receivers with high temperature molten salts mixtures under the Thermal Energy Lab鈥檚 6.5kW solar simulator facility.

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Molten salts are excellent heat transfer fluids that can be used for a variety of thermal management applications and enable clean energy technologies with high power densities. However, they are typically very challenging to heat to high temperatures using internal electric heating systems rather than burning fossil fuels or using expensive circulation heaters. The Thermal energy Laboratory is currently developing alternate molten salt heating systems based on electrode and induction heating. These heating systems are to be used for molten salt thermal energy storage charging systems, as well as volumetric heating of molten salts for lab-scale nuclear power research and experimentation. This project is ideal for students interested in renewable energy and experimental heat transfer.

(1) Design a lab-scale experimental testing facility for an electrode and induction heating system, (2) purchase and assemble materials and equipment, and (3) conduct preliminary lab-scale experimentation.

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For surgical training, virtual surgical planning and numerical model validation, reproducible synthetic arterials mockups (phantoms) are needed. These models need to replicate the mechanical properties of native tissue (hyperelastic, anisotropic, heterogeneous). The large deformation, the layered structure and pathological degradation of the vessel need to be mimicked. In this regard, we initiated the development of anthropomorphic tissue-mimicking mockups (TMM) that exhibit the major mechanical, anatomical and pathological characteristics of vessels (hyperelasticity, viscoelasticity, friction). The TMM is made of a cryogel, polyvinyl alcohol cryogel (PVA-C), which has excellent biocompatibility and is suitable for imaging modalities. By varying the parameters during cryogel fabrication, it possible to tailor the mechanical properties of PVA-C to that of human arteries. The project aims particularly and the viscoelastic characterization.

The candidate will help in characterizing the mechanical properties of the synthetic vessels and pathological calcium synthetic inclusions, fabricating the phantoms and incorporating the calcium inclusions structures in the artificial vessels and subsequently test the phantoms using medical imaging.

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According to the American Heart Association cardiovascular disease affects 36.9% of the population, with approximately 30% of patients suffering from coronary artery disease. Acute Coronary Syndrome, associated with myocardial infarction, requires fast diagnosis and revascularization. Traditionally clinicians have chosen treatment methods by estimating the amount of flow going through the diseased coronary artery. Although several methods exist, catheter based pressure measurements are widespread among clinicians. Fractional flow reserve (FFR) is an index of the physiological significance of a coronary stenosis and is a measure of the maximal blood flow in a diseased artery to normal maximal flow. It is measured by comparing the pressure before and after the diseased arterial section, and thus indirectly estimating the loss of myocardial perfusion. Our partner has developed a FFR technology based on a photonic principle instead of the piezoelectric principle of the conventional technologies. This new photonic based technology has the potential to be more sensitive than current piezoelectric based technologies. We are currently in the stage of evaluating the navigation and positioning precision of their technology (delivery in tortuous vessels and positioning at the stenotic site). This project is about developing a testing rig that reproduces the physiological blood flow to test the new technology.

The candidate will help develop a dedicated dynamic phantom in-vitro model to study the navigation and positioning parameters and the associated hemodynamic disturbances associated with the technology.

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Vascular scaffolds have been widely studied for the treatment of critical limb ischemia (CLI). However, the risk of postoperative restenosis raises the need of other factors that regulate inflammation or intimal growth. A combination therapy with mechanical support using a bioresorbable scaffold (bioresorbable stent) and biochemical cues from stem cell-derived nanovesicles as a coating for drug deliver is put forward for better patient outcomes and faster recoveries. In this study, the main objective is to design, develop and test a new bioresorbable scaffold coated stent based on stem cell-derived nanovesicles for higher biocompatibility and enhanced therapeutic efficacy. Stent geometries will be generated and modelled numerically for assessing deployment and drug dispersion kinetics. The best concepts will be prototyped with laser micro-machining. In collaboration with the partner, the prototypes will be coated with the nano-vesicles technology.

The student will be involved in the stent geometry generation (CAD drawings), optimization for the application and prototyping using micro-laser machining.

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Transfer learning driven defect classification for metal additive manufacturing based on vision signals - machine learning experience preferred.

Metal additive manufacturing provides great promise to build complex geometries and repair worn out components. A key challenge lies in the lack of process reliability and repeatability. Process monitoring appears to be a suitable solution for early detection of defects. Among various monitoring techniques, vision-based process monitoring has been found to effectively capture the features of melt pool during material deposition. These techniques can generate large datasets from continuous monitoring of printing process. A major bottleneck lies in the accurate labeling of the samples for subsequent learning task. The labels come from expensive and time-consuming experiments and are relatively few as compared to available unlabeled data or complexity of learning task. As a result, we are interested to see if techniques such as transfer learning, domain adaptation, and multi-task learning can be used to find similarity between the labelled data and unlabeled samples. Specifically, feature-similarity based transfer learning techniques will be investigated to label images captured during the process monitoring. The augmented dataset will be used to train deep models to evaluate the effectiveness of transfer learning techniques used. There are two research tasks. Task 1: Develop an effective transfer learning/domain adaptation technique to label image dataset. Task 2: Evaluate the effectiveness of each technique by developing deep models on the augmented dataset

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Professor Sharf is carrying out research on increasing robotics and automation in tree harvesting machinery. These machines are mobile robots: they include a large crane-like manipulator and a mobile base. Several projects are being worked on by Sharf's graduate students. One project addresses the problem of motion planning for a forestry machine while maintaining stability of the machine. This work is motivated by the fact that these machines often operate on steep slopes and are prone to roll-over. In this context, we would like to carry out the following sub-projects: 1) We want to use the robotic arm in our lab, Jaco 2, to test the motion planning algorithms that we developed to ensure that the arm remains dynamically stable as it moves with or without a payload (in the context of forestry machines, the payload is trees or logs). To this end, we envision instrumenting the table supporting Jaco 2 with load cells which would measure the location of zero-moment point as the arm is moving and therefore allow us to validate our motion planning algorithms. 2) We have been working on the motion planning for forestry machines that take into account the uncertainties in the slope of the terrain. We would like to see if using low-cost IMU sensors, we could quantify the uncertainties in the terrain, by installing the IMU on a small vehicle and driving it over uneven surfaces. This work will be carried out in close collaboration with Professor Sharf's PhD student, Hunter Song.

1) design the experimental set up for determining the zero moment point for the Jaco 2 arm 2) spec out the required sensors and instrumentation 3) carry out experiments with Jaco 2 arm 4) post-process data 5) select a low-cost vehicle for driving on uneven ground and integrate an IMU box onto the vehicle 6) conduct tests with the vehicle to collect IMU data 7) post-process data

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