Paper 2: Behaviour of Rarefaction Waves at the Junction of a Branched Duct
The results of an investigation into the behaviour of rarefaction waves at a junction formed by the intersection of two ducts are presented. Pressure measurements have been made in junctions in which the side branch forms an angle of 45°, 90°, and 135° with the main branch. In the 90° junction the effect of the area of the side branch to that of the main branch is examined; the values of the ratios being 1·0, 0·5, and 0·25. The amplitude of the incident rarefaction waves varies from 3 to 20 inHg. The development of the quasi-steady flow pattern has been obtained by Schlieren photography. This information, together with the pressure measurements, has been used to develop a quasi-steady, one-dimensional, semi-empirical analysis of the flow. The results of this analysis are in good agreement with the pressure measurements and can be used as boundary conditions for the examination of pipe networks by the method of characteristics.