DEVELOPMENT OF UNSTEADY GAS FLOW GENERATOR WITH HIGHLY PRECISE INLET FLOW RATE CONTROL SYSTEM

In industry, an unsteady flow rate measurement of gases is becoming important increasingly. Our group has been developed an unsteady flow generator with an isothermal chamber for gases and showed that the calibration of the dynamic characteristics for the tested flow meter was effective. However, not only the measurement of the instantaneous flow rate value but also the evaluation of the time mean value in the unsteady flow becomes important in industry. And it was difficult to control precisely the time mean value of the generated flow rate using the former unsteady flow generator which we developed. In this research, to improve the precision of the generated flow rate with the unsteady flow generator, we suggest the inlet flow rate control method with the sonic nozzle and the high precise pressure control system and apply this method to the developed generator. Moreover, we perform the experiments and uncertainty analysis and confirm the effective of the suggested method.