Peter Oshkai

Peter  Oshkai
Mechanical Engineering
Office: Engineering Office Wing, Room 529

BA (Lehigh), MS (Lehigh), PhD (Lehigh)

Area of expertise

Unsteady flows, flow-acoustic coupling, fluid-structure interactions

Research description

Peter Oshkai's research focuses on complex flows using techniques of quantitative imaging and computational fluid dynamics (CFD). Research at the Fluid Mechanics Laboratory aims at revealing new physical phenomena that have a major impact both in terms of applied technology and fundamental knowledge. Applications include:

  • flow-induced noise and vibrations,
  • multi-phase flows,
  • energy harvesting,
  • biomimetic propulsion,
  • biomedical devices.

Our current focus areas are:

Underwater radiated noise (URN) from marine vessels

Propeller-induced cavitation dominates the URN emitted by ships, presenting a significant threat to marine ecosystems. Designing mitigation strategies for noise pollution requires predictive models, which are challenging to develop due to the varied, multiscale, and multi-physical nature of the phenomenon. We use a combination of CFD solutions of the flow in the wake of ships, experimental investigation of the cavitation bubble dynamics and field measurements of the URN of ships.

Tidal turbines

Marine renewable energy sector has received significant attention from the countries around the world. Canada’s longest coastline in the world offers a great potential for clean energy and economic opportunities in this area. Our current research focusses on vertical-axis tidal turbines that have a number of advantages over other configurations, including relative ease of installation and maintenance and reduced impact on aquatic life. Despite these advantages, a number of technical challenges exist for large-scale projects that involve operation of turbine arrays. These include uncertainties associated with the effects of turbulence and complex seafloor topography on the turbine operation. Our research aims to address these issues by performing a comprehensive experimental study of model-scale turbines under repeatable laboratory conditions using state-of-the-art laser-based flow imaging techniques. 

Energy harvesting by oscillating foils

The use of oscillating foils for hydrokinetic energy harvesting has been receiving interest in recent years, promising to overcome some of the limitations of established renewable energy technologies related to cost effectiveness and intermittency energy supply. These systems consist of a foil that undergoes periodic translating and rotating motions in an incoming flow. These lift-based turbines have been shown to reach energy extraction efficiencies matching or exceeding their traditional rotary counterparts. Oscillating foil turbines are particularly well-suited for shallow and wide flow channels, where their rectangular cross-sections can harvest large portions of the flow. Moreover, they can operate efficiently in slower flows than conventional rotary designs. We aim to improve performance of  passively oscillating foil turbines by investigating the governing mechanisms of the fluid-structure interactions using a combination of particle image velocimetry (PIV) and CFD.

Droplet impact dynamics

Impact of liquid droplets on dry or wet surfaces is a complex physical phenomenon that is common in nature and engineering. The range of practical applications of droplet impacts include fuel injection, spray coating, spray cooling and biomedical devices. Our research aims to provide insight into the governing physics and to develop methods of control of the splash dynamics with application to bioprinting. Using multiple types of cells in 3D bioprinting requires robust methods of cell differentiation. Some of the promising techniques involve cell differentiation by mechanical means, i.e. pressure and shear stress. Our current research involves high-speed photography of the droplet impacts under varying ambient pressure conditions. The goal is to improve the understanding of the resulting splash dynamics, which would enable development of novel bioprinting technology.