Optimization of a micro turbojet engine combustion chamber
LI Dongjie1, ZHOU Bohao1, LIANG Qian2, LAN Xudong1
1. Aero Engine Research Center, School of Aerospace Engineering, Tsinghua University, Beijing 100084, China; 2. Beijing Institute of Space Long March Vehicle, Beijing 100076, China
Abstract：Micro turbojet engine combustor designs cannot be directly scaled from large aero-engine combustion chamber designs due to the different fuel supply modes and inflow conditions that affect the micro turbojet combustor efficiency. Bad designs lead to high wall temperatures, poor combustion stability and nonuniform outlet temperature distributions. Both ANSYS and CFX were used in this study to analyze the air flow and combustion characteristics in the combustion chamber of a micro turbojet engine. The numerical simulations were validated by comparisons with cold state tests. A "gas swirling liquid" design was then developed to improve the combustion. The numerical simulation results show that this design reduces the combustion chamber outlet temperature distribution coefficient from the traditional 0.54 to 0.15, which greatly improves the combustion chamber and turbine efficiencies and the thermal efficiency, and the thrust of the micro turbojet.
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2021, Vol. 61 
