Heat Dissipation Characteristics Analysis of Surface Air-Oil Heat Exchanger Applied in Aircraft Engine

In order to enhance aircraft engine heat transfer performance in the conditions of ground idle speed or low flying speed, a surface air-oil exchanger was presented using air inlet passage as its dissipation area. Its heat dissipation characteristics, as well as districted simulation equivalence, were investigated through the studies of 4 districted mode, 7 districted mode and the mode of using flat surface to replace arc surface. The numerical results demonstrate that temperature distributions in air side are almost the same in the cases of 4 districted mode, 7 districted mode and the mode used flat surface to replace arc surface in the simulations. All of their temperature differences are smaller than 1 K, and the discrepancies of calculated heat dissipation power are below 5%. The phenomena of heat transfer in oil side are also the same in the three cases. The research validates the feasibility and reliability of the methods of using districted simulation and using flat surface instead of arc surface where the ratio of arc length to diameter is below 0.203, when analyzing thermal characteristics of a large surface heat exchanger.