Sina Kheirkhah

Associate Professor

Mechanical

Office: EME4233
Phone: 250.807.9428
Email: sina.kheirkhah@ubc.ca

Research Summary

Combustion; Turbulence; Laser-based diagnostics; Low/zero carbon fuels; Sprays; Gas turbine engines.

Courses & Teaching

Combustion Processes; Thermodynamics, Laser-based measurements for fluid flows.

Biography

Dr. Kheirkhah is an assistant professor at the University of British Columbia at the Okanagan campus. He received his Ph.D. from the University of Toronto Institute for Aerospace Studies (UTIAS), investigating fundamental combustion science at the propulsion and combustion laboratory. Following his doctoral degree, he was awarded the NSERC postdoctoral fellowship, and he studied combustion instabilities, specifically thermo-acoustics, that occur in commercial aircraft gas turbine engine combustors at the University of Toronto’s experimental engines laboratory. Dr. Kheirkhah has lectured combustion processes and fluid mechanics at the University of Toronto’s faculty of engineering and applied science prior to joining UBC.

Combustion for Propulsion and Power laboratory aims at training highly qualified researchers whose investigations will allow for developing technology, tools, and knowledge that help aircraft and large-scale power generation industries for mitigation of combustion instabilities and design/improvement of next generation combustion engines. Our laboratory always looks for hiring motivated students; for opportunities (both Ph.D. and masters positions), please contact Dr. Kheirkhah.

Websites

Combustion for Propulsion and Power Laboratory

Degrees

NSERC Postdoctoral Fellow, University of Toronto
Ph.D. in Aerospace Engineering, University of Toronto
M.A.Sc. in Mechanical Engineering, University of Waterloo
B.Sc. in Mechanical Engineering, Sharif University of Technology

Research Interests & Projects

Thermoacoustics

Thermoacoustics (heat release and pressure) oscillations often arise in combustion equipment, e.g., gas turbine engines. In-phase heat release and pressure oscillations result in a positive net energy transfer to the engine, which causes resonance, and, in extreme cases, engine destruction.

The figure below is obtained from simultaneous and spatio-temporally resolved measurements of pressure and heat release rate inside a gas turbine engine combustor. The blue and red regions are associated with positive and negative energy transfer to the system, respectively. Studying dynamics of these oscillations allows for understanding the underlying reasons that drives themoacoustic oscillations. This understanding is crucial for development of themroacoustic mitigation technology.

Turbulent Premixed Combustion

Development of current and next generation gas turbine engine combustors requires computation fluid dynamics efforts, specifically, large eddy simulations. These simulations substantially rely on accurate sub grid scale models that can be obtained from experiments. These models will have to be developed for conditions that replicate real engineering applications. Figure below demonstrates how imporoving turbulence conditions towards those of realistic engineering applications changes topology of turbulent premixed flames.

Flame-Vortex Interaction

Turbulence is a complex subject by nature. It is even more complex at the presence of heat release- that is when flames are present. Interaction of turbulent flow with flame fronts simplified to interaction of an individual vortex with a flame surface can provide stepping stones towards understanding and solving the complex problem of turbulent combustion. Studying this interaction allows for development of efficiency functions used in simulation of turbulent flames that are in turn utilized in design of engineering equipment. Figure below is obtained from high resolution Rayleigh scattering measurement and shows how temperature fields evolve during such vortex and flame interactions. Blue and red regions are associated with minimum and maximum temperatures, respectively. This project requires combination of several high resolution and/or high speed cameras along with pulsed lasers. Thus, the project is currently performed within measurement campaigns and in collaboration with Professors Fabien Halter (from University of Orleans, France) and Adam Steinberg (from University of Toronto, Canada).

 

Selected Publications & Presentations

The list of publications