Abstract
It is difficult to measure the flow rate of compressible fluids especially the unsteady flow, because the density of them changes largely with the temperature. Therefore, there is no effective method for testing the dynamic characterisitics of air flowmeters. If there is an apparatus which could generate the unsteady flow, the dynamic characterisitics of air flowmeters could be measured. It is known from our previous study that the isothermal condition during air discharge or charge can almost be realized by stuffing the steel wool into the chamber. Then, the flow charged into or discharged from the chamber becomes only the function of pressure. Hence, the both steady and unsteady flow rate is obtained by differentiating the pressure in the chamber during air charge or discharge.
In this study, an apparatus which could generate the desired flow rate of compressible fluids using the isothermal chamber is proposed. The flow rate can be generated by controlling the pressure in the chamber during air discharge with a servo valve. Both the steady and unsteady oscillating flow could be generated with the apparatus. The performance of the generator was examined by experiments and confirmed its effectiveness.
