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针对发动机燃烧室由于高温升和低污染而使可用冷却空气大量减少的技术难题,设计了一套切向进气发散小孔的单管燃烧室模型.使用热流固耦合方法,通过对Navier-Stokes(N-S)方程的求解,对其流场特性和火焰筒壁温进行了数值模拟研究.计算在三维坐标系下,采用拉格朗日法计算燃油颗粒的轨迹,非预混模型计算燃烧,离散坐标模型计算辐射,使用标准k-ε湍流模型,在固壁附近运用壁面函数法,计算了两种工况的火焰筒壁温分布.结果表明,在燃烧室总油气比为0.046,冷却空气质量分数为30%,进口空气总温为830 K,总压为3 MPa工况下,燃烧室最高壁温为1 015 K,温度梯度最大为22.5 K/cm,完全满足推质比为12一级的军用发动机和民用发动机对燃烧室火焰筒在冷却空气质量分数为30%、总油气比为0.046条件下对于壁温的要求.
Aiming at the technical problem that the combustion chamber of the engine reduces the available cooling air greatly due to the high temperature rise and the low pollution, a single-tube combustion chamber model of tangential intake divergent orifice is designed.Using the method of thermo-fluid-solid coupling, (NS) equation, the numerical simulation of flow field characteristics and flamethick wall temperature was carried out.Calculation In the three-dimensional coordinate system, the trajectory of the fuel particles was calculated by Lagrangian method, the non-premixed model was used to calculate the combustion, discrete The standard model was used to calculate the radiation and the standard k-ε turbulence model was used to calculate the wall temperature distribution of the flame wall in two conditions by using the wall function method near the solid wall. The results showed that when the total gas-oil ratio in the combustion chamber was 0.046 and the cooling air quality The maximum wall temperature of the combustion chamber is 1 015 K and the maximum temperature gradient is 22.5 K / cm under the condition of 30% of the total inlet air temperature, 830 K of total inlet air pressure and 3 MPa of total pressure. Of the military engine and civilian engine on the combustion chamber flame tube cooling air mass fraction of 30%, total oil and gas ratio of 0.046 conditions for the wall temperature requirements.