Skip to content. Skip to main navigation.

MAE Seminar: Ignition Transients in an Ethylene Fueled Scramjet Engine

Friday, September 20, 2019, 2:00 PM - 2:50 PM
Nedderman Hall Room 105

Add to Calendar

Liwei Zhang
Assistant Professor, UTA Dept. of Mechanical and Aerospace Engineering

Abstract:

The scramjet engine is one of the most promising candidates for hypersonic flight propulsion systems for air-launched vehicles for access to space. At high flight speeds (Mach numbers greater than 8), the flow remains completely supersonic throughout the scramjet combustion chamber. The shock waves in the inlet are relatively stable, and increase the pressure and temperature of the air being delivered to the combustion chamber. Fuel-air mixing, ignition and flame stability are, however, become serious concerns in the high-speed flow environment, especially with hydrocarbon fuels. The situation is particularly challenging during the engine start-up stage, when the low chamber pressure and unsettled fuel-air mixing tend to blow off the flame, even if a flame holding device such as a cavity is employed.

The first part of this presentation will introduce the basic concepts and recent advancement in the development of scramjet engines. The major concerns in engine component designs and propellant selections will be discussed.

The second part of this presentation will address the challenge of combustion at high speeds from the perspective of high-fidelity modelling and simulation. Modeling of these problems is complicated by the highly nonlinear source terms arising from compressibility effects and chemical reactions. The widely disparate time and length scales involved impose stringent requirements on numerical simulation algorithms, computing resources, and post-processing of results. An integrated theoretical and numerical framework has therefore been established to study injection, ignition, and combustion in a scramjet combustor test facility that simulates hypersonic conditions. Active control schemes have been developed to ensure rapid ignition and sustained combustion during the engine start-up stage. This presentation will highlight the complex physiochemical processes of mixing and combustion, and their significance in the performance of scramjet engines.

Bio:

Liwei ZhangLiwei Zhang is an assistant professor in the Department of Mechanical and Aerospace Engineering.  Before joining UTA, she was a research engineer in the Daniel Guggenheim School of Aerospace Engineering at the Georgia Institute of Technology.  She received a B.S. in Theoretical and Applied Mechanics from the University of Science and Technology of China and a Ph.D. in Mechanical Engineering from the Pennsylvania State University. Her research interests include multi-fidelity modeling and simulation of turbulent reactive flows, combustion dynamics in propulsion and energy-conversion systems, and data-enabled design and data science.

Return to Upcoming Events

 ∧