Abstract:

The two-iblet micro aerodynamic valve is presented in this article to solve the lowefficiency problem of the micro triangular valve. Based on twostage contractive riblets with transition arc, the tworiblet aerodynamic valve reduces the pressure loss of the airflow in the positive direction, and divides the airflow in the negative direction into three currents. The three currents converge in "Y" shape afterwards, collide with each other intensely and then dissipate some kinetic energy, leading to the reduction of mass flow rate in the negative direction and the increase of the valve efficiency.The working principle of the two-riblet aerodynamic valve is studied and testified by numerical simulation.The triangular,trapeziform and two-riblet aerodynamic valve samples with a feature size of 1 mm are fabricated by means of wire-electron discharge machining and EDM.A new experiment method is designed and experimental studies are carried out on micro flow testing platform.The results show that the two-riblet aerodynamic valve improves efficiency remarkably: under incompressible condition,the efficiencies of the triangular and trapeziform valves are around 2%-3%,and that of the two-riblet aerodynamic valve is about 14%; under compressible condition,the two-riblet aerodynamic valve enhances the efficiency to 13% as compared with 2% of the other two valves.

Key words: active , flow , control,  , two-riblet , aerodynamic , valve,  , micro , valve,  , micro , jet,  , MEMS