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长微直管道内多流态并存的流动特性研究不仅有理论意义 ,而且在太空飞行器的控制系统中有着重要的应用价值 .采用实验研究和理论模型近似分析相结合的方法研究了长微直管道内的气体流动特性 .实验中 ,以空气为工作介质 ,进口压力分别设定为 1 30 ,2 5 0 ,32 0kPa ,出口压力变化范围为 9— 1 0 0kPa .沿程分布有五个测压点 ,进出口设有温度传感器 ,测量出口流量的同时可以得到沿程压力分布 .近似理论模型采用二维平板近似模型 .研究发现 ,在保持进口压力不变、不断降低出口压力的条件下 ,当进出口压比低于 5 .3左右时 ,质量流量随压比增加而增加 ;当进出口压比高于 5 .3左右后 ,微管道内流动的质量流量随压比的增加变化很小 ,基本上趋近于某个常数 ,并且出口处的压力扰动波很难向上游传播 .将此现象定义为亚堵塞现象 ,并将发生该现象时对应的进出口压比定义为亚堵塞临界压比 .同时进一步研究了亚堵塞现象与S V(表面积与体积比 )值之间的关系
The research on the flow characteristics of co-existence of multi-flow in a long and straight pipe is not only of theoretical significance, but also has important application value in the control system of a spacecraft. By means of the combination of experimental research and theoretical model approximation, In the experiment, the air as the working medium, the inlet pressure were set to 130, 250, 32 0kPa, the outlet pressure range of 9-1 0 0 kPa along the distribution of five manometry Point, the inlet and outlet with a temperature sensor, the outlet flow measurement can be obtained along the pressure distribution along the way.Approximate theoretical model using two-dimensional flat-panel approximation model.Studies found that maintaining the inlet pressure constant, continuously reducing the outlet pressure conditions, when When the pressure ratio of inlet and outlet is lower than about 5.3, the mass flow rate increases with the increase of the pressure ratio. When the pressure ratio of inlet and outlet is higher than about 5.3, the mass flow in the microchannel changes little with increasing pressure ratio, Basically close to a certain constant, and the outlet of the pressure disturbance wave is difficult to spread upstream.This phenomenon is defined as the phenomenon of sub-clogging, and the phenomenon of the corresponding import and export pressure Ratio is defined as the critical pressure ratio of sub-blockage.At the same time, the relationship between sub-blockage and S V (surface area to volume ratio)