射流流量计的仿真与试验研究

以流场仿真为基础,设计射流流量计内部流道结构,研究射流流量计内部流场的速度分布和压力分布,并研究射流附壁诱发流体交替振荡的机理,提出主射流的偏转过程实际上是两个共同作用于主射流的涡流强弱交替的过程。在此基础上,以仿真模型优化射流流量计,通过试验验证射流振荡的效果以及管道流速与流体振动频率之间的特性关系。并设计出计量范围0．55～6．50 m／s(气体介质)、精度等级高于2级的射流传感器,为射流流量计的结构改进和优化设计提供了有效的途径。

NUMERICAL SIMULATION AND EXPERIMENTAL STUDY ON FLUIDIC FLOWMETER

Numerical simulation is applied to design the internal flow passage of a fluidic flowmeter and research on the velocity distribution and pressure distribution of the flow field in the fluidic flowmeter, as well as the mechanism of fluid alternation and oscillation induced by the Coanda effect. The results of the simulation indicate that the deflection of main jet is always accompanied with strength alternation of two vortexes acting on the main jet together. Subsequently a fluidic flowmeter prototypeis optimized based on the simulation model. Experimental study is carried out to verify the effects of fluidic vibration and the characteristic relationship between conduit velocity and vibration frequency. A fluidic flow sensor with a measuring range from 0.55 m/s to 6.5 m/s for gas medium and an accuracy grade higher than grade 2 is finally developed. Hence effective methods of structural improvement and optimum design for fluidic flowmeter are provided.