Geometric and numerical simulation models of lobed mixer with variation of the ratio of height to width (h/b) of lobe were created based on a lobed mixer in the forced mixing exhaust system of turbofan engine with constant lobe number and lobe length.Though three-dimensional numerical simulation

the principle of the effect of different ratios of height to width in a forced mixing exhaust system was obtained.The results show that at the exit section of the force mixing exhaust system

when the width of lobe is constant

the thermal mixing efficiency rises as h/b increases;however

when the height of lobe is constant

the mixing efficiency declines with rise of h/b.Besides

as h/b augments

the total-pressure recovery coefficient decreases if the width of lobe is unchanged

or increases if the height of lobe is invariable.