나선형 원형핀 튜브 적용 자동차용 오일쿨러 성능 특성에 관한 연구

The aim of this study is to investigate the performance of air-cooled oil-cooler with spiraled-coiled circular fin-tube using analytic and experimental methods. Due to environmental regulation as a global issue, fuel efficiency is getting more important with respect to Research and Development in the field of a vehicle. As a power transfer unit, transmission affects fuel economy considerably. Therefore, transmission is supposed to keep in the optimal operating condition, which transmission oil cooling seems to be key factor for transmission operation. To cool the automated transmission fluid, air-cooled oil-cooler has been applied for large-sized diesel segment and premium sedan because of cost effectiveness. In this study, the study to substitute for present air-cooled oil-cooler which has PF(Parallel flow) tube and louvered fin was performed with analytic approach and experimental analysis in order. After optimal design was decided with respect to fin, proto-type oil-cooler with the spirally-coiled circular fin and tube was fabricated. Then, tests were fulfilled according to test conditions from OEM. As the results of the experiment, heat cacpaity and oil-side pressure drop is inferior to present oil-cooler by 70% and 100%, respectively. However, air-side pressure drop is a bit superior by 100% because of widened free path. At this stage, spirally-coiled circular fin-tube oil-cooler seems to be not capable to substitute for PF type oil-cooler. Therefore, further study is necessary to improve the performance with respect to fin and tube.