内燃波转子热射流点火装置射流特性研究

Research on Jet Performance of a Hot Jet Igniter

关键词:  内燃波转子  点火  热射流点火  射流核心  射流特性

Key words:  Wave rotor combustor  Ignition  Hot jet ignition  Jet core  Jet performance

摘要:

为了将热射流点火更好地应用于内燃波转子，采用数值模拟的方法，针对所设计的热射流点火装置进行射流特性研究，分别研究了流量变化与喷管结构对热射流特性的影响。研究结果表明随着进口流量的增加，射流核心长度增加，而喷管出口面积减小并不能增加射流核心长度，如在进口流量为1.23g/s时，喷管直径小于7mm后射流核心长度急剧下降，但是喷管出口面积减小大幅度增加了射流动量。在相同位置特征截面上，核心区射流能量随质量变化呈线性分布，动量呈二次分布。

Abstract:

For better application of the hot jet igniter to wave rotor combustor，a numerical study on hot jet performance is conducted according to a specially designed hot jet igniter. The effects of mass flow rate and nozzle structure on the hot jet characteristics are studied respectively. The results indicate that the jet core length increases with the increase of inlet mass flow rate. However，decreasing the nozzle outlet area would not increase the jet core length，for example，jet core length decreases sharply when inlet mass flow rate is 1.23g/s on the condition that nozzle diameter is less than 7mm. Besides the decrease of nozzle outlet area leads to the increase of jet momentum substantially. Jet energy in the core region presents linear distribution while the momentum shows quadratic distribution with respect to mass flow rate in the same characteristic section.