Numerical Study of Internal and External Flow Mixing for Rectangular Nozzles with Large Aspect Ratio

The mixing characteristics of external flow with jets from five rectangular nozzles with aspect ratio of 1,4,8,12,16 and from an axisymmetric nozzle were studied numerically.All nozzles studied had equal exit area.The results show that the rectangular nozzles lead to a relatively shorter jet core region and faster velocity and temperature decay rate than the axisymmetric one on centerline.This trend increases with the increase of aspect ratio.