STG-4 Experimental Study of the Shell Nozzle Entry Region
Three different impingement devices for the shell nozzle entry region—solid plates, perforated plates, and rod grids—have been studied experimentally in a small model unit using air as the test fluid. The effect of various geometric parameters on the pressure drop and the flow distribution was studied for each impingement device. A comparison of different devices was made, which showed that the rod grid device gives best overall results in terms of velocity distribution and pressure drop. Inlet zone pressure drops were correlated over a wide range of geometry variations by empirical approaches. Resulting predictions were very good for the data from this model unit. The methods used will be further evaluated with respect to possible update of general nozzle pressure drop prediction methods in the HTRI computer programs.