Research on Conjugate Heat Transfer and Flow of Rib and Film Cooling Structures under Anisotropic Thermal Conductivities
Numerical calculations were carried out on the overall heat transfer characteristics of conjugate heat transfer and flow of rib and film cooling structures under anisotropic thermal conductivities.The o-verall cooling efficiencies,the Biwer number,and the interaction of the film cooling with the rib and the effect of both on the cooling under the influence of anisotropic thermal conductivities for cooling channels with continuous rib,smooth and interrupted rib were compared and analyzed.Overall cooling characteris-tics of different cooling channel models were investigated under the conductivity ratios of 1,2 and 5 and main thermal conductivity directions along the X,Y and Z axes for flat plane.The results show that the increase of main thermal conductivity coefficients has little effect on the average overall cooling efficiency,but makes the cooling distribution more uniform.The average overall cooling efficiency under main ther-mal conductivity direction along the Z-axis is 5%-9%higher than any other case,the average overall cooling efficiency under main thermal conductivity direction along the X-axis is the lowest and the distri-bution of the cooling zone is more concentrated.The ribs can improve the average overall cooling efficien-cy by 2%to 5%compared with smooth channels,and the interrupted ribs have better performance than continuous ribs.The outlet temperature of the film hole is 14-18 K higher under main thermal conduc-tivity direction along the Z-axis than that under the other two directions,and this temperature affects the actual film cooling efficiencies.The total efficiency of the rib is about 1.7%higher under main thermal conductivity direction along the Z-axis compared to that under the other two directions and the total heat transfer coefficient is about 4.7 times higher than that under the other two directions.
anisotropic thermal conductivity coefficieintsfilm coolingribbed channelconjugate heat transfer and flownumerical simulation