燃料喷射位置对凹槽火焰稳定特性的影响

采用混合分数平衡化学模型,燃烧与紊流相互作用的PDF模型和离散液滴模型,研究了不同位置喷射燃料对双模态冲压发动机燃烧室中煤油超声速燃烧凹槽火焰稳定特性的影响。结果表明,凹槽内均出现燃料和空气的混气,以及燃烧产生的高温区,可以达到稳定火焰,增强燃烧的目的;从凹槽局部参数以及燃烧室壁面静压的分布来看,凹槽上游0位置喷射燃料,更有利于燃料与空气的混合、燃烧,并且燃烧室总压损失较小,是最佳的喷射方式。验证了我们在实验研究中的所采取的设计方案。同时,有关煤油超声速燃烧的研究可以通过数值实验,并对实验测量起到指导作用,从而减少风洞实验次数。

The effect of the different fuel injection on the cavity flame holding characteristic in kerosene supersonic combustion

The effect of the fuel injection with different location on the cavity flame-holding characteristic was numerically investigated in kerosene dual-mode supersonic combustion with the mixture-fraction equilibrium chemistry model and the probability density function model,combining with the discrete droplet model.There are air-fuel evaporation mixtures and high temperature regions in the cavities with re-circulation flow,so they would provide stable flame holding and enhance combustion.In view of the local parameters distributions in the cavities and the wall static pressure of the combustor,the injection of cavity with the upstream 0 location is very good for the mix and combustion of fuel and air, and the total pressure loss is relative small at the combustor exit.The 0 location injection is the optimum injection means.The result validates the design scheme in the experimental test.The CFD simulation is an important tool to predict the relative kerosene supersonic combustion and provides some directions for the test measure.So the test could be decreased in the tunnel.