Calculation of Lobe Mixer Flow with Reynolds Stress Model

Abstract

Lobe mixer is a special nozzle equiped in a turbofan engine to increase the thrust efftciency and suppress the noise. At present the design depends on systematic experiment because the flow field is too complex to be represented with an eddy viscosity model. Although it is neccesary to use a Reynolds stress model(RSM), conventional ones have not taken account of 3 dimensional application. We extended Launder-Reece-Redi model and constructed a new low Reynolds number type RSM. To determine unknown constants and to confirm the ability 2 dimensional channel flow was calculated. The agreement between the calculation and the experiment is satisfactorily good. Then we applied it to the lobe mixer and showed that it can reproduce the flow qualitatively.