Study on the compressible viscous flows through a straight pipe

Abstract

When sonic nozzles of significantly smaller diameter are used as standard flow meters, the critical backpressure ratio is affected by the boundary layer at the nozzle throat. It is known that, as the flow pathway is complicated in actual valves, the critical pressure ratio differs from the ideal value. However, the effect of the boundary layer thickness on choking criteria is still controversial. Choking phenomenon in a sonic nozzle fitted with a straight circular pipe of variable length is investigated numerically and the results are compared with experimental and theoretical ones. The results show that the actual critical pressure ratio is less than the ideal value and it decreases with increase in pipe length. The effect of boundary layer thickness on main flow Mach number is also made clear in this work. In addition, sonic conductance and pressure loss in actual viscous flows computed are compared with the ISO 6358 standard.

The Taylor-Proudman column in a rapidly-rotating compressible fluid I. energy transports

“…(30a)-(30c) will be stated as the conditions for the T-P column in a compressible rotating fluid. The result may be helpful to further study such as a practical application on compressible pipe flow [Lijo et al [21]]…”

“…(34b). The above physical interpretations may be better understood by resorting to a more realistic exemplary flow such as compressible pipe flow [21]. Consider an isothermal horizontal disk which rotates faster than the interior flow.…”