A general structural design methodology for multi-hole orifices and its experimental application

Compared to single-hole orifices (SOs), multi-hole orifices (MOs) have smaller orifice sizes and various patterns of orifice distribution. The geometric description of MOs is more complex, increasing the difficulty of MO structural design. Therefore, it is worthwhile to investigate the key factors affecting MO throttle or flow control characteristics and to develop a general MO design method. This work presents a practical geometric design methodology for MOs and applies this procedure in throttle experiments. To describe the MO geometry in detail, the methodology first introduces a comprehensive set of geometric architectures involving orifice arrangement criteria and geometric parameters such as the total orifice number, n; the orifice distribution density, Dd; and the equivalent diameter ratio, EDR. Then, a series of throttle tests in water flow are conducted to investigate the effect of various geometric features on the pressure loss characteristics of MOs. Finally, a simple model to calculate the pressure loss coefficient of MOs is presented.