Numerical Investigation on Flow and Heat Transfer Characteristics of Three-dimensional Corrugated Impingement/effusion Cooling System
To further enhance the heat transfer potential of impingement cooling,an impinge-ment/effusion cooling system in which the jet plate was designed as a three-dimensional corrugated shape is proposed based on a typical impingement/effusion system.The three-dimensional corrugated plate consists of a superposition of transverse(X)and longitudinal(Y)sinusoidal wave systems,and the jet holes are arranged at the trough of the sinusoidal waves.The numerical simulation of the impingement/effusion system was conducted by utilizing the Realizable k-ε turbulence model based on the Reynolds time-averaged Navier-Stokes equation.The differences in flow and heat transfer coefficient between the three-dimensional corrugated plate and the flat plate were compared and the effect of wave amplitude(A)was studied.The jet Reynolds number based on the jet hole diame-ter(Red)and dimensionless wave amplitude(A/d),with a parameter range of 300<Red<3000 and 0.5<A/d<1.1 were studied respectively.Meanwhile,the hole pitch at the transverse and longitudi-nal direction and impingement distance are fixed as S/d=10.0,P/d=5.0 and H/d=3.0,respectively.Compared with the experimental results,the Realizable K-ε turbulence model gives accurate predic-tions for the line-averaged and area-averaged Nusselt numbers(NuAve,(Nu)).The three-dimensional corrugated plate reduces the momentum loss before the jet impinges on the target(effusion)plate and significantly improves the heat transfer coefficient near the stagnation point.When A/d=0.8,the maximum improvement in the NuAve within 1.5d from the stagnation point is 32.3%.With the increase of A/d,the heat transfer in the stagnation region is enhanced,but the heat transfer outside the stagnation region is unchanged.The improvement of changing A/d on Nu is affected by Red,and the improvement of (Nu)corresponding to the increase of Red from 300 to 3000 is reduced from 36.6%to 11.6%.With the increase of Red and A/d,the flow coefficient gradually increases and the flow coefficient of the three-dimensional corrugated plate is higher than that of the flat plate,but the improvement is less than 3%.
vectoring nozzleimpingement/effusion coolingthree-dimensional corrugated plateflow and heat transfer characteristicsnumerical simulation