基于引射器函数法的程序优化设计及验证

针对考虑多因素综合影响的引射器优化问题,基于引射器函数法,深入研究了静压协调函数的数学特性并分析了其数学曲线上的奇异点。在此基础上,通过程序设计和基准推进归纳法得到了多分支工作特性曲线,分析了不同分支下解的特性。另外结合工作特性曲线重点研究了混合室背压、主次流总压比和混合不均匀度对引射性能的影响,提出了静压特性曲面、临界曲线的设计概念。通过试验数据对比分析验证了引射器函数法的可靠性。结论表明:靠近临界曲线工况时引射器设计性能较好;混合不均匀度对引射性能影响重大,不均匀度为1.5时对比理想状态,引射系数最大误差达到32.73％;考虑壁面摩擦设计时需对摩擦因数公式模型进行修正。研究结果为引射器优化设计提供了重要指导。 

Program optimization design and verification based on ejector function method

In view of the ejector optimization problem considering the comprehensive influence of multiple factors, based on the ejector function method, the mathematical characteristics of static pressure matching function were studied and the singular points on the mathematical curve were analyzed. On this basis, the multi branch characteristic curves were obtained by programming and benchmark progression induction method, and the characteristics of solutions under different branches were analyzed. In addition, the influences of mixing chamber back pressure, total pressure ratio of primary and secondary flow and mixing nonuniformity on the ejector performance were studied, and the design concepts of static pressure characteristic curve and critical curve were proposed. The reliability of the ejector function method was verified by comparing with the experimental data. The results showed that the design performance of the ejector was better when it was close to the critical curve. The mixing nonuniformity had a great influence on the ejector performance, when the nonuniformity was 1.5, compared with the ideal state, the maximum error of the ejecting coefficient reached 32.73%. When considering the wall friction design, the friction coefficient formula model should be modified. The results provide an important guidance for the optimal design of ejector.