微型喷管内气体流动的流量壅塞现象  

Phenomenon of Gas Flow Choking in Micro-Nozzles

作　　者：丁英涛[1] 谢君堂[1] 仲顺安[1] 

机构地区：[1]北京理工大学信息科学技术学院电子工程系,北京100081

出　　处：《北京理工大学学报》2006年第12期1086-1089,共4页Transactions of Beijing Institute of Technology

摘　　要：基于MEMS微加工工艺,在硅片上加工出带有内部测压孔的微型喷管,其喉部宽度为20μm,深度为240μm,扩张比为1.7,采用实验研究和数值计算相结合的手段研究了微型喷管内气体的流动特性.研究结果表明:保持进口压力不变,不断降低背压,当喉部马赫数达到0.8时,内部流动出现了质量流量壅塞现象.此时对应的壅塞临界压比为0.650;同时发现,当进出口压差为48 kPa和66 kPa时,喉部下游扩张段出现了局部超声速环.这些异于常规喷管流动特性的现象主要归因于微型喷管内较大的粘性耗散.With micro fabrication technology, a micro nozzle with a throat width of 20μm, depth of 24μm and expansion ratio 1.7 was fabricated on a silicon wafer. Experiments and numerical simulation were done for a study of flow chracteristics. The mass flow rate and pressure distributions were measured under different inlet-outlet pressure difference. Results of numerical simulation showed that when the throat＇s Mach number came near to 0.8, the choking of mass flow rate appeared and the corresponding choking critical-pressure-ratio was about 0. 650. Moreover, in the divergent area of the micro nozzle, a closed supersonic region occured when the inlet-outlet pressure difference were near 48 kPa and 66 kPa. These particular phenomena as were different from conventional scale could be attributed to the higher viscous dissipation owned by the micro nozzles.

关 键 词：微型喷管 流量壅塞 数值计算 声速点 

分 类 号：TN4[电子电信—微电子学与固体电子学]