In this study, the CFD analysis was performed by changing the geometry of coil-tube diameter ratio, coil winding number, coil pitch, and cross section of the tube to investigate the heat flow characteristics of forced convection in a helical coil-tube heat exchanger using RSM (Reynolds Stress Model). As a result, the secondary flow was developed in the tube caused by the influence of centrifugal force. It improved the heat transfer on the outer side of the tube, but on the inner side was not performed well. And the temperature rose locally in the tube region. Also the pressure drop in the tube was proportional to the diameter ratio of the coil-tube and the inlet velocity, and it was found that pressure drop and friction factor were inversely proportional. When the coil winding number and coil pitch were increased, it affected heat transfer in the low speed range of 0.1 ~ 0.2 m/s, but did not affect the flow condition after this range.

ABSTRACT
 1. 서 론
 2. 해석모델
  2.1 지배방정식
  2.2 수치해석
  2.3 난류모델의 타당성 검증
 3. 결과 및 고찰
  3.1 나선형 튜브내의 유동특성
  3.2 나선형 튜브내의 열전달특성
  3.3 나선형 튜브의 기하학적 변화에 따른 열전달특성
 4. 결 론
 References

• 이원재(College Undergraduate, Department of Mechanical Engineering, Gachon University) | Won-Jae Lee
• 김진황(College Undergraduate, Department of Mechanical Engineering, Gachon University) | Jing-Hwang Kim
• 윤준규(Department of Mechanical Engineering, Gachon University) | Jun-Kyu Yoon Corresponding Author