爆震室壁面条件对脉冲爆震发动机爆震性能的影响

发布时间：2018-05-05 09:42

本文选题：脉冲爆震发动机 + 增强装置　；参考：《力学季刊》2016年04期

【摘要】：在爆震室内快速形成稳定传播的爆轰波是脉冲爆震发动机的关键.本文利用有限速率化学反应模型,考虑粘性、热对流,基于N-S方程对氢气与空气/氧气为反应混合物的爆震发动机爆震室内流场进行计算.从流场压力、速度、涡量、湍流动能等方面研究爆震室壁面条件对燃烧爆轰性能的影响,分析流场爆轰波压力与流场湍动能的关系,讨论可燃气体燃烧转爆轰的机理.结果表明:爆震室内燃烧爆轰机理受到化学反应能量释放、壁面摩擦效应、壁面与外界热交换的影响.在文中讨论的范围内,相比于半圆形和三角形的爆震室装置,矩形的爆震室增强装置能在更短的时间内得到较高的爆轰波压力和湍动能峰值.壁面粗糙层高度(粗糙度)影响爆震室的燃烧爆轰性质.当壁面粗糙度为0.15mm时,粗糙度对爆轰的激励作用大于抑制作用,能较快形成稳定的爆轰波,且推力为35.5N;随着壁面对流换热系数的增大,爆震室壁面的散热加剧.当壁面对流换热系数大于临界值2.6W/(m2·K)时,爆震室内不能形成稳定的爆震波.
[Abstract]:The rapid formation of stable detonation wave in detonation chamber is the key of pulse detonation engine. In this paper, a finite rate chemical reaction model is used to calculate the detonation chamber flow field of a detonation engine based on N-S equation considering viscosity and heat convection. The effects of wall conditions of detonation chamber on combustion detonation performance are studied from the aspects of flow field pressure, velocity, vorticity and turbulent kinetic energy. The relationship between detonation wave pressure and turbulent kinetic energy in flow field is analyzed, and the mechanism of combustion to detonation of combustible gas is discussed. The results show that the detonation mechanism in detonation chamber is affected by chemical reaction energy release, wall friction effect and heat exchange between wall and outside. In the range discussed in this paper, compared with the semi-circular and triangular detonation chamber devices, the rectangular detonation chamber intensifier can obtain higher detonation pressure and turbulent kinetic energy peak in a shorter time. The height of rough layer (roughness) affects the detonation properties of detonation chamber. When the wall roughness is 0.15mm, the excitation effect of roughness on detonation is greater than that of suppression, and the stable detonation wave can be formed quickly, and the thrust is 35.5N. with the increase of wall convection heat transfer coefficient, the wall heat dissipation of detonation chamber increases. When the wall convection heat transfer coefficient is larger than the critical value 2.6W/(m2 K), the detonation chamber can not form stable detonation waves.
【作者单位】：上海大学上海市应用数学和力学研究所;
【分类号】：O382.1

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