NUMERICAL INVESTIGATION ON THE EFFECT OF THE SIZE AND NUMBER OF STAGES ON THE TESLA MICROVALVE EFFICIENCY

In the present study, the effect of the number of stages of Tesla Micro-Valve (TMV), as well as the dependency of Reynolds number, Re, on the valve performance has been analyzed. For this purpose, different layouts include one to four-stage with different sizes are investigated numerically. The main criterion for evaluation of valves performance is diodicity, Di. Unsteady and steady flow in valve have been simulated and compared. It is shown that although there are some difference but the trend is similar for both responses. Finally, 2-D and steady state computations of the fluid flow have been utilized that reveal a strong dependence of Di on Re and pressure drop, P. The results showed that the maximum Di of the two-stage microvalve is approximately 1.45 times of that of one-stage. Additional stages increase the complexity, and they do not change Di appreciably. It is concluded that two-stage layout of Tesla type valve is the best option. Also, the two-stage valve performance for three different sizes is compared with Nozzle-Diffuser type Micro-Valve (NDMV). Comparisons, which are performed based on calculation Di in applicable range of Re, showed that Di as a function of Re is independent of the valve size. Also, the superiority of the Tesla type valve at higher Re and its weakness at lower Re is observed.