Study of Compressible High Speed Gas Flow in Piping System : 3rd Report, Flow Characteristics in Junctions

抄録

The effects of compressibility on the flow losses at the high sub-sonic speed in piping systems with junctions are investigated experimentally in this report. Experiments were carried out varying the angle between the axes of pipes, the size of the radius of the edge at the joining corners and inner surface roughness of the pipe junctions as well as the flow Mach number. The effects of compressibility on Kc are expressed by the following empirical formula, Kc/Ki=1.0+α Mβ where Kc is the compressible flow loss coefficient at junctions, sub-script i refers to an incompressible flow and α, β are experimental constants. Furthermore, the flow patterns at junctions were visualized by means of Schlieren techniques, and loss characteristics were discussed on the basis of the photographic records. Finally, a practical computing method of the flow losses in a high speed pipe flow is described.