Estimation of Pressure Loss in Ring-Type Exit Chambers

A simple Borda-Carnot type of analysis is presented which enables an estimate to be made of the pressure loss in the exit chamber of an axial-flow turbomachine. Based upon the recent experimental investigation of Escudier and Merkli [1], it is argued that the loss is primarily accounted for by dissipation of the vortex generated in ring-type exit chambers by the tangential inflow. For the most part this dissipation occurs in the outlet tube from the exit chamber. The analysis is particularly useful in providing a qualitative guide for the design engineer as to the influence on performance of changing the geometric proportions of an exit chamber.