Session: 04-10 Combustion V

Submission Number: 178420

Research on Effects of Carbon Soot on Lean Blowout Limit of Evaporative Flameholder 

Abstract: The Air Turbo Rocket (ATR) Engine, which is composed of gas generator, turbo and afterburner, is characterized by its wide velocity domain and large airspace. The function of the afterburner is to facilitate the efficient combustion of the gas produced by the fuel-rich combustion of liquid oxygen and kerosene within the gas generator, together with the compressed air by the compressor. Due to the fuel-rich combustion in the gas generator, the presence of evident carbon soot in the core gas significantly affects the lean blowout (LBO) limit of the afterburner. In this paper, an experiment and numerical simulation were conducted on a model combustor assembled with an evaporative flameholder to study the LBO performance, flame structure and carbon soot distribution under different inflow conditions. Some conclusions are obtained as follows: 1) The effect of carbon soot mass flow rate on LBO FAR(fuel/air ratio) is different under different incoming temperature. When the carbon soot mass flow rate is 0.9g/s and 1.7g/s, the LBO FAR is decreased by 16.7% and 26.6% compared with that there is no carbon soot in incoming flows under the inlet temperature is 463K. When the inlet temperature is increased to 533K, the FAR at LBO is increased by 22% and 31.7% under the carbon soot of 0.9g/s and 1.7g/s. 2) When the mass flow rate of carbon soot is 0 g/s, the FAR at LBO is decreased firstly and then increased with the increase of the tailing edge velocity, whereas for carbon soot mass flow rates of 0.9 g/s and 1.7 g/s, the FAR at LBO shows a monotonically increasing trend. The mass flow rate ratio of incoming carbon soot to incoming air is between 0.16% and 0.48%, which is matched with the carbon soot concentration in the ATR engine's afterburner. 3) In terms of the flame structure, as the mass flow rate of carbon soot is increased, the flame surface exhibits greater fluctuations and the flame area is increased. 4) According to the results obtained by laser induced incandescence (LII), it is observed that the high carbon soot concentration region is located at the center of recirculation region, showing a V-shaped distribution. When the mass flow rate of carbon soot is changed from 0 g/s to 1.7 g/s, the carbon soot distribution is changed from a V-shaped distribution to a uniform distribution, and the recirculation zone disappears.

Keywords: carbon soot, lean blowout limit, flameholder, laser induced incandescence, recirculation regions.

Presenting Author: Qing Liu School of Aeroengine, Shenyang Aerospace University

Presenting Author Biography: This author is a doctoral student, and his main research area is combustion in the afterburner.

Authors:

Qing Liu School of Aeroengine, Shenyang Aerospace University
Wen Zeng School of Aeroengine, Shenyang Aerospace University
Bin Hu Institute of Engineering Thermophysics, Chinese Academy of Sciences;National Key Laboratory of Science and Technology on Advanced Light-duty Gas turbine, Institute of Engineering Thermophysics;School of Aeronautics and Astronautics, University of Chinese Academy of Sciences;Jinan Institute of Advanced Gas-turbine
Zhonghua Wang Institute of Engineering Thermophysics, Chinese Academy of Sciences;Jinan Institute of Advanced Gas-turbine
Wei Zhao Institute of Engineering Thermophysics, Chinese Academy of Sciences;National Key Laboratory of Science and Technology on Advanced Light-duty Gas turbine, Institute of Engineering Thermophysics;School of Aeronautics and Astronautics, University of Chinese Academy of Sciences;Jinan Institute of Advanced Gas-turbine
Qingjun Zhao Institute of Engineering Thermophysics, Chinese Academy of Sciences;National Key Laboratory of Science and Technology on Advanced Light-duty Gas turbine, Institute of Engineering Thermophysics;School of Aeronautics and Astronautics, University of Chinese Academy of Sciences;Jinan Institute of Advanced Gas-turbine;Beijing Key Laboratory of Distributed Combined Cooling Heating and Power System, Institute of Engineering Thermophysics, Chinese Academy of Sciences