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Browsing Articles by Author "Adair, D."

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    CFD Modelling of Flow Characteristics in Micro Shock Tubes
    (Journal of Applied Fluid Mechanics, 2017-04-12) Mukhambetiyar, A.; Jaeger, M.; Adair, D.
    The use of micro shock tubes has become common in many instruments requiring a high velocity and temperature flow field, for example in micro-propulsion systems and drug delivery devices for medical systems. A shock tube has closed ends, and the flow is generated by the rupture of a diaphragm separating a driver gas at high pressure from a driven gas at relatively low pressure. The rupture results in the movement of a shock wave and contact discontinuity into the low-pressure gas, and an expansion wave into the high pressure gas. The characteristics of the resulting unsteady flow for micro shock tubes are not well known as the physics of such tubes includes additional phenomena such as rarefaction and complex viscous effects at low Reynolds numbers. In the present study, computational fluid dynamics (CFD) calculations are made for unsteady compressible flow within a micro shock tube using the van-Leer MUSCL scheme and the two-layer turbulence model. Novel results have been obtained and discussed of the effects of using different diaphragm pressure ratios, shock tube diameters and wall boundary conditions, namely no slip and slip walls.
  • Thumbnail Image
    ItemOpen Access
    CFD Modelling of Flow Characteristics in Micro Shock Tubes
    (Journal of Applied Fluid Mechanics, 2017) Mukhambetiyar, A.; Jaeger, M.; Adair, D.
    The use of micro shock tubes has become common in many instruments requiring a high velocity and temperature flow field, for example in micro-propulsion systems and drug delivery devices for medical systems. A shock tube has closed ends, and the flow is generated by the rupture of a diaphragm separating a driver gas at high pressure from a driven gas at relatively low pressure. The rupture results in the movement of a shock wave and contact discontinuity into the low-pressure gas, and an expansion wave into the high pressure gas. The characteristics of the resulting unsteady flow for micro shock tubes are not well known as the physics of such tubes includes additional phenomena such as rarefaction and complex viscous effects at low Reynolds numbers. In the present study, computational fluid dynamics (CFD) calculations are made for unsteady compressible flow within a micro shock tube using the van-Leer MUSCL scheme and the two-layer turbulence model. Novel results have been obtained and discussed of the effects of using different diaphragm pressure ratios, shock tube diameters and wall boundary conditions, namely no slip and slip walls.
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    Development of a Design Tool for Optimization of Voltage Generation from a Bimorph Piezoelectric Cantilever Beam
    (Materials Today: Proceedings, 2017-01-01) Mukhanov, A.; Abdigaliyev, A.; Jangeldinov, B.; Zhussip, M.; Zhapparov, R.; Ruderman, A.; Adair, D.; A., Mukhanov
    Abstract Mechanical energy is one of the most common forms of energy which can be harvested from our everyday environment, and, piezoelectric (PZT) materials are widely used as transducers for converting mechanical energy, often in the form ambient motion (usually vibration) into electrical energy. Central to the design process of the energy harvesting device, which involves various interrelated parameters, is the need to quickly and efficiently optimize the key design parameters using validated analytical modelling. Hence in this work, a design tool built on vibration theory of an Euler-Bernoulli cantilever beam, and, a realistic equivalent circuit model for a piezoelectric generator with a resistive load is developed.