| The louvered fin radiator was widely used in the cooling system of automobile due to its high compactness, low weight and low cost. Although the louvered fin geometry of heat exchanger had been proposed in 1950s, the flow and heat transfer characteristics of the louvered fin radiator weren't be analyzed and understood until 1970s. Because of the complexity of the geometrical structure and flow structure, the experiment researches on the louvered fin radiator were very difficult. By employing the numerical simulation, the distribution and variation of thermal parameters such as pressure, velocity and so on in the louvered fins can be conducted in detail, on the basis of which, we can optimize the geometry structure, shorten the design period and reduce the experimental and design cost. In previous researches, the numerical simulations were mainly focused on the convective heat transfer in the fluid zone of the louvered fin geometry. Virtually, the heat conduction in the fins and the convective heat transfer of air are coupled each other. In this paper, the numerical method was used to investigate the 3-D coupled heat conduction-convective heat transfer, the structured unstructured meshes were applied to discretize the computational zone. The effect of fin pitch, louver pitch, louver angle and etc. on the heat transfer and flow performance were studied. The computed results showed that: a. It is feasible for CFD software to be used to simulate the coupled heat transfer in the louvered fingeometry. b. A little fin pitch can result in better heat transfer performance under the same other structure parameters. c. A little louver pitch can result in better heat transfer performance under the same other structure parameters. d. When the ratio of louver pitch to fin pitch is LP/FP=1.25, the integral performance of the louvered fin radiator is favourable. In this paper, the complex flow and coupled heat transfer in the louvered fin radiator were numerically simulated, and the effect of each geometry structure parameter was systematically analyzed. The studied results provide scientific basis for the design and optimization of the louvered fin radiator, which have an important engineering value in a certain extent, it is useful to optimize the automobile cooling system. |
