The effects of different ratios of height to width of lobe mixers on the flow field

thermal mixing efficiency

total-pressure recovery coefficient and thrust coefficient were studied when the areas of inner duct and outlet duct kept constant in turbofan aero-engine forced mixing exhaust system. Geometric models with various ratios of height to width of lobed mixer in turbofan aero-engine forced mixing exhaust system were built

and the numerical simulation methods based on Navier-Stokes equations were conducted. The results indicate that at the exit section

if the areas of inner duct and outlet duct keep constant

in a range of ratios of height to width of 2 to 4.5

the thermal efficiency of lobed mixer has the trend of increasing

decreasing and increasing again

and at last the inflection points of efficiency function curve are at 3 and 3.21. In addition

with the increase of ratio of height to width

the total-pressure recovery coefficient and thrust coefficient also decrease.