不同结构的冷却管脉冲射流流动响应特性

探究了结构参数对脉冲射流经冷却管内流动响应规律。在脉冲频率为1 Hz，雷诺数为5 000，脉冲射流占空比为50%的气动参数下，对冷却管管径、射流孔孔径、孔间距的变化对脉冲射流流动响应特性带来的影响依次分析，对结构参数对脉冲射流在冷却管内流动响应特性产生影响的内在机制进行综合阐述。针对上述结构参数拟合出冷却管射流质量系数随冷却管管径、射流孔孔径、孔间距变化的经验关系式，为优化阵列脉冲射流的冷却管结构设计提供数据基础。研究发现，冷却管射流速度的响应时间、迟滞时间均随着冷却管管径、射流孔孔间距和孔径的增加而减小。随着冷却管管径增大，射流孔孔径减少，孔间距减少，冷却管内射流速度系数增大，冷却管内压力增大，流容减少。 

Pulse jet flow response characteristics of cooling pipe with different structures

The flow response law of pulse jet through cooling pipe with structural parameters was explored. Under the aerodynamic parameters of pulse frequency of 1 Hz，Reynolds number of 5 000 and pulse jet duty ratio of 50%，the influences of cooling pipe diameter，jet hole diameter，hole spacing on the pulse jet flow response characteristics were analyzed successively and the internal mechanism of the influence of structural parameters on the flow response characteristics of pulse jet in the cooling pipe was comprehensively described.In view of the structural parameters，empirical formulae of the cooling pipe jet quality coefficients with cooling pipe diameter，jet hole diameter，hole spacing were fitted to optimize the array of pulse jet cooling pipe chamber，providing a reference for structure design.It was found that the response time and hysteresis time of cooling pipe jet velocity decreased with the increase of cooling pipe diameter，hole spacing and jet hole diameter.With the increase of cooling pipe diameter，the decrease of jet hole diameter and hole spacing，the pressure in the cooling pipe and the jet velocity coefficient increased，and the flow capacity decreased.