摘要
一、数据的采集与处理 热线所采集的瞬时电压值E与实际速度值的关系可由下两式表达: E^2=A+BZ^(1/2)+CZ,Z^2=V^2+GU^2+KW^2 (1)其中Z为有效冷却速度,V、U、W为三方向瞬时速度,其余为相应的系数。按以上关系可用直单丝进行三维流场的测量。本文与文献[1]的主要区别有以下两点: 1.改进采集方式:由于文献[1]的采集与处理是利用二次仪表一均方根电压表进行的,而(1)式却无法将有效冷却速度Z直接表达为平均电压或均方电压O_E^2的函数,
Periodic flow appears in many practical flow fields, such as the flow in compressors. The unsteady flows induced by both periodic fluctuation and the turbulence may dramatically affect the flow which is often three-dimensional . A modification to the single hot wire technique developed in Ref. [1] has been made to measure time mean 3-D turbulent flow field. It incorporates computer-controlled sampling, disposing and analyzing. The Triple Decomposition method has been further incorporated into the technique to treat 3-D unsteady turbulent flow. The measuring system is fully automized. The experiments done in authors'laboratory have demonstrated the advantages of the technique.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
1989年第2期155-157,共3页
Journal of Aerospace Power
