摘要
为了进一步提升冲击冷却的强化换热潜力,在典型冲击/发散结构的基础上提出了一种冲击板为三维波纹板的冲击/发散冷却结构。三维波纹板由横向(X)及纵向(Y)的正弦波系叠加而成,冲击孔布置在正弦波的波谷位置。通过基于雷诺时均N-S方程的Realizable k-ε湍流模型进行了冲击/发散结构的数值模拟,对比了平板结构与三维波纹板结构在射流流动及靶面换热特性上的差异并研究了波纹板波幅(A/d)的影响规律。其中基于冲击孔直径d定义的射流雷诺数的研究范围为Red=300~3000,波纹板波幅的研究范围为A/d=0.5~1.1,冲击孔的横向间距、纵向间距及冲击距分别为S/d=10.0,P/d=5.0,H/d=3.0。结果表明:与实验结果相比,Realizable k-ε湍流模型能够对线平均及面平均努塞尔数(NuAve,^(—)Nu)给出准确的预测;三维波纹板结构相比平板结构降低了射流冲击靶面前的动量损失,显著提高了驻点附近的换热强度,当A/d=0.8时,距冲击驻点1.5d范围内NuAve的最大增幅为32.3%;随着A/d的增大,冲击驻点区的换热得到明显强化,但驻点区以外的换热基本不发生改变。改变A/d对^(—)Nu的增益效果受到Red的影响,在A/d=1.1时,Red由300增大到3000对应的^(—)Nu增幅由36.6%降低为11.6%;随着Red和A/d的增大,流量系数(Cd)逐渐增大,三维波纹板结构的流量系数大于平板结构,但增幅小于3%。
To further enhance the heat transfer potential of impingement cooling,an impingement/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-εturbulence 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 diameter(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 longitudinal 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-εturbulence model gives accurate predictions 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
作者
李国栋
郭涛
马钊
刘存良
孔德海
LI Guodong;GUO Tao;MA Zhao;LIU Cunliang;KONG Dehai(School of Power and Energy,Northwestern Polytechnical University,Shaanxi,Xi’an 710129,China;AECC Sichuan Gas Turbine Establishment,Sichuan,Chengdu 610500,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2024年第1期212-222,共11页
Journal of Engineering Thermophysics
基金
国家科技重大专项资助项目(No.J2019-III-0019-0063,No.J2019-II-0022-0043)。
关键词
矢量喷管
冲击发散冷却
三维波纹板
流动及换热特性
数值模拟
vectoring nozzle
impingement/effusion cooling
three-dimensional corrugated plate
flow and heat transfer characteristics
numerical simulation
