초록
컴퓨터용 방열기의 헤더부 튜브 삽입길이에 따른 열전달 및 유동특성을 파악하기 위하여 수치해석을 수행하였다. 튜브삽입길이 0, 5, 10mm의 3가지 해석모델을 선정하였으며 해석결과의 타당성 검증을 위해 삽입길이가 5mm 일 때 샘플을 실험결과와 비교하였다. 유량분배의 균일성을 판단하기 위해 각 튜브에서 유량비를 분석하였고, 유량분배 특성을 정량적으로 비교하기 위하여 유량균일도를 정의하였다. 해석결과를 통하여 모든 샘플에서 열전달량과 압력강하는 질량유량이 증가함에 따라 점차 증가하였으며, 튜브삽입길이가 10mm(h/D=0.5)인 샘플 3의 열전달량과 압력강하는 가장 크게 나타났다. 유량균일도(Stotal )를 조사하였을 때 튜브삽입길이가 0mm(h/D=0)인 샘플 1이 0.0052로 가장 균일한 유량분포를 보였다.
The performance of flat-tube radiators with louvered fins was numerically investigated for different tube insertion lengths. The results of numerical analysis using CFX-11 were compared with experimental results. In this study, three types of flat-tube radiators with louvered fins were considered. An experiment was conducted to validate the numerical results. Flow rate ratio (FR) and Stotal were introduced to understand the uniformity of flow distribution easily. The results of numerical analysis revealed that the heat transfer rate and pressure drop increased as the mass flow rate increased. Further, the results showed that the heat transfer rate of sample 3 with h/D = 0.5 was higher than that of the other samples. The pressure drop increased as the insertion length toward the header part increased, and the pressure drop in the case of sample 3 appeared to be the highest. The factor Stotal showed that the uniformity of the flow distribution in the case of sample 1 with h/D = 0 was higher than that in the case of the other samples.