三股互击式喷注器及燃烧室流场的数值模拟

摘要

The chemical reactions in combustor are described by integrating Eddy-Dissipation Model with Arrhenius rate coefficients.The cold and react flow fields of triplet impingement injector and combustor are simulated using the three-dimensional computational fluid dynamics method.Both helicity and mixing length are introduced to study the mixing mechanism and the effect of triplet impingement injector.The key characteristic parameters of combustor,e.g.,spatial distributions of total temperature and pressure,residence time of gas flow in combustor,are obtained.The flow field characteristics of triplet impingement injector and combustor for Fuel-Oxidizer-Fuel （F-O-F） and Oxidizer-Fuel-Oxidizer（O-F-O） triplet arrangements are analyzed.The degree of F_2 dissociation in combustor exit plane for O-F-O triplet arrangement is 13.5%higher than that for the F-O-F triplet arrangement under conditions of specified composition proportioning and combustor characteristic length.Experimental result demonstrates that the output power of laser is increased by 17%.%结合旋涡耗散模型及Arrhenius化学反应速率系数来描述燃烧室内的化学反应,对三股互击式喷注器及燃烧室的冷流场及有反应流场进行了三维的数值模拟研究.引入螺旋度及混合长度参量分析了三股互击式喷注器的混合机理和混合效果,获取了燃烧室的关键特征参数,如总温、总温的空间分布、气流在燃烧室内的驻留时间等.对燃料组合分别采用F-O-F,O-F-O的喷注器及燃烧室的流场特性进行了比较分析.对于一定的燃料配比和燃烧室特征长度,燃料组合采用O-F-O时,在燃烧室出口的F2解离度比F-O-F要高出13.5%.实验证实激光器出光功率提升了17%.