Abstract
In this study, the analysis of the turbulent flow separation on the wall of the main conduit in a pipe fitting with branching angleθp of 135° is presented. The flow in the pipe fitting is analyzed by the free-streamline theory. Then the separation point of the turbulent flow is analyzed using the boundary layer theory. The calculated results indicate that the separation point χs/h1 (h1 denotes the upstream section of the main conduit.) depends on the area ratio m, the length of the upstream section of the main conduit l1d/h1, the Reynolds number Re1r and the ratio of lateral discharge to total discharge Q2/Q1. Also, the experiments were made on the same conditions for the analysis. The experimental reseults show that χs/h1 is dependent on m and Q2/Q1. When l1d/h1 and Re1r are large enough, the values of χs/h1 obtained by the experiment indicate that the same tendency as the calculated ones. But the values of χs/h1 obtained by experiment are usually smaller than those obtained by the calculation. Therefore, the separation point of the real flow exists farther upstream than that of the calculation.
