High-Fidelity Simulation of Combustion Processes in Liquid Rocket Engines

摘要

The combustion characteristics of oxygen and kerosene in liquid rocket engines are investigated using large eddy simulation. These engines operate at pressure levels higher than the critical pressures of propellants, i.e., supercritical conditions. A theoretical and numerical framework along with real-fluid thermodynamic and transport properties is implemented. The turbulence/chemistry interaction is treated using a laminar flamelet approach. The resultant scheme provides high-fidelity information of flame fields that are extremely challenging to capture in experiments. Two types of swirl-related injectors are considered, bi-swirl and jet-swirl. Oxygen and kerosene are both tangentially introduced into the injector for the former, while oxygen is axially injected and kerosene is tangentially introduced for the latter. The flow and flame structures are presented. The flame anchors at the injector post in the recess region for both cases, and is further stabilized by the recirculation zone immediately downstream of the injector. The kerosene film flows along the injector surface because of the swirl-induced centrifugal force, and provides effective thermal protection to the surface against the heat flux in the flame zone. The dynamic responses of the combustion filed is currently underway to explore the stability characteristics.