Flow Characteristics and Methods of Flow Calculation of High-speed Compressible Flow through Pipe Orifices

Flow characteristics of a compressible gas flow through an orifice are investigated experimentally at pressure ratios below the regulation values of JIS and ASME. For practical mass flow measurements, a theoretical method of mass flow estimations is extended using one - dimensional flow theory and experimental data. Using the method, the accuracy of mass flow measurements with orifice meters is about ±1% in the Reynolds number range of turbulent flows and also in supercritical flows. Tables of the product of flow coefficient and expansion factor are obtained by the method at various diameter ratios, pressureratios, and specific heats.