Research On Heat Transfer And Resistance Characteristics Of Low-finned Tube Oil-cooler

Research on the heat transfer and resistance characteristics of the low-finned tube tubularoil-cooler is carried on by the ways of numerical simulation and experimental investigation.The simulation is focused on the factors that affect the performance of the oil cooler, such asthe fins spacing(t), oil flow(ws),oil viscosity and oil temperatures(T) by using the Fluentsoftware, and a comprehensive factor () is introduced to determine the effects of each factoron the overall performance of the oil cooler. The purpose is to get the most reasonable rangesof the fin spacing, Reynolds number(Re), temperature and other parameters.The experimental study, which compares low-finned tubes and smooth tube oil cooler,focuses on the exchange heat (Q),total heat transfer coefficient(k) and oil load pressuredrop(p o). And then the simulation and experimental results are analyzed by software of dateprocessing. Finally, the simulation and experimental results of the low-fin oil cooler tube arecompared and analyzed to verify the reasonableness of numerical simulation results. And theexperimental results are compared with the literature.The main contents and conclusions are as following:(1) When the fin pitch is2mm, as the Reynolds number changes from504to2014, heattransfer coefficient of the oil side changes from414.8~694.5W/(m2K), increasing almost1.7times. constantly changes with the Reynolds number, and totally decreases about77%.When the Reynolds number range from504to838, the oil cooler has higher total heattransfer characteristics.(2) when=50L/min, the heat transfer coefficient of oil side continuously decreasesfrom445.6W/(m2K) to343W/(m2K). with changing from2mm to5mm. changesslowly from22.9to19.6kPawith the increase of.The oil cooler with=2mm~3mm hasbetter heat transfer characteristics.(3)When=2mm and=30L/min, the heat transfer coefficient changes from492.8977W/(m2K) to503.48389W/(m2K) with the oil temperature changing from40℃to90℃, and the growth trend becomes faster. changes from10.6kPato7.6kPaas thetemperature rising. In the range of80℃~90℃, the comprehensive performance of the oilcooler reaches a higher level.(4) Comparison of the performance of low finned tubes and smooth tube, the amount ofheat exchange of the former increased by about10%to20%compared to the latter. On resistance performance, the former compared to the latter increased by10%to15%. Comparethe k of the two kinds of oil coolers, oil cooler with low fin tube increased by20%~25%,and the value of increased by25%to30%.(5) Choosing the low fin tube oil cooler with structure of t=2mm and h=1mm to study.Simulation and experimental dates are analyzed by software of date processing, which isintended to get the relational expression of Nu and f.(6) The difference of the pressure drop between the simulation and experiment valuescould reach about10%. It means that the simulated pressure drop value is in a reasonablerange. Comparison of the total heat transfer coefficient values, the simulation value is higherthan the experimental value of11%to26%, within the acceptable range. Experimental resultsbetter than the results in the literature，it is of great significance to do the research.