Study on radiation heat transfer characteristics of aeroengine combustion chamber

航空发动机燃烧室辐射传热特性研究

School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China

Received: 30 June 2023

Abstract

The thermal radiation of gaseous combustion products in an aero-engine combustion chamber has obvious non-ash-body characteristics. In this paper, based on the OpenFOAM platform, a numerical study on multi-field coupled turbulence-combustion-radiation radiative heat transfer was carried out for a certain type of aero-engine combustion chamber using the mean weighted sum of grey gas (WSGG) gas radiation model, which can accurately describe the non-ash characteristics of the gas. The results show that the radiation heat transfer characteristics are influenced by several factors such as equivalent ratio, combustion pressure and wall emissivity, among which the equivalent ratio is dominant. Increasing the equivalence ratio from 0.11 to 0.4 resulted in a 189% increase in average incident radiation at the combustion chamber wall and a 233% increase in average incident radiation at the exit. Increasing the equivalent ratio, combustion pressure or wall emissivity will increase the average radiation intensity in the combustion chamber and the inhomogeneity of radiation distribution at the exit of the combustion chamber. The radial radiation distribution factor (RRDF) also increases with the increase of equivalent ratio, combustion pressure and wall emissivity.

摘要

航空发动机燃烧室气态燃烧产物热辐射具有明显的非灰体特性。基于OpenFOAM平台, 采用能准确描述气体非灰体特性的灰气体均值加权和(WSGG)气体辐射模型, 针对某型航空发动机燃烧室开展了湍流-燃烧-辐射多场耦合辐射换热数值研究。结果表明, 辐射换热特性受到当量比、燃烧压力、壁面发射率等多个因素的影响, 其中当量比占主要地位, 当量比从0.11提升至0.4, 燃烧室壁面平均入射辐射增加189%, 出口处平均入射辐射增加233%。当量比、燃烧压力、壁面发射率增大会提高燃烧室内平均辐射强度及燃烧室出口处辐射分布的不均匀性。径向辐射分布系数(radial radiation distribution factor, RRDF)随着当量比、燃烧压力、壁面发射率的增加而增大。