| Radiator is a very important part of automobile cooling system, its ma in function is transfer the heat of the hot coolant to the outside air through the metal flat tube and fin, make the temperature of the coolant always stay within a reasonable range, and ensure the norma l operation of the engine. With the ascension of the modern engine technology, the engine deve lopment in the direction of the high power and low emissions, higher requirements of the automobile cooling system’s reliability, power consumption, quality and compact structure were proposed. We should improve the heat transfer performance, reduce the air side resistance, developing new and efficient heat transfer surface, light weight, sma ll size of the radiator at the primary stage of radiator development. Using CFD technology can greatly save development costs and shorten the development cycle.Using wind tunnel experiment to research the performance of louvered fin, quadratic polynomia ls were used to fit the test data, which maximum deviation is less than 5%. A three dimensiona l numerica l model was established for heat exchanger with louvered fin, using the CFD software FLUENT simulate the air side friction and the water side heat exchanger performance with the coupled compute method. It is found that both heat transfer and friction performance are in good agreement with the test result. By calculating the j factor, f factor and the optimum factor a of different fin spacing and fin heights, an optima l louvered fin structure was put forward. The result offers a principle and direction for optimal design of multi-louvered fins heat exchangers.Through the study of this article we can find that wind speed on the radiator cooling performance and the influence of the air side pressure drop is greater than the water flow. By calculating factor a of all mode ls in this paper, we can conclude that the fin height is 5.5 mm and 2.4 mm fin spacing of the radiator has the optimizing combination property. |
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