연성체를 이용한 열전달 향상 시스템 수치해석

국문 초록 (Abstract)

열전달은 다양한 산업에서 시스템 설계 시 반드시 고려해야만 하는 중요한 분야이며, 많은 연구자들이 열전달을 향상시키기 위해 다양한 형태의 와류 생성기를 도입하였다. 강체 와류 생성기의 경우 높은 압력 강하로 인해 에너지 손실이 크게 발생하여 최근에는 연성의 성질을 갖는 와류 생성기를 이용하여 열전달 향상을 도모하는 연구들이 활발히 진행되고 있다. 본 연구에서는 채널 중심축에 대해 비대칭적으로 기울어진 연성 와류 생성기를 이용한 열전달 향상 시스템을 수치적으로 분석하였으며, 유체-연성체-열 상호작용을 고려하기 위해 가상경계기법을 사용하였다. 와류 생성기의 굽힘 계수가 일정할 때, 기울어짐 각도가 증가할수록 와류 생성기의 펄럭임 현상이 크게 나타났으며, 펄럭임 운동에 의해 와류 구조가 생성되어 열전달이 증가되었다. 기울어짐 각도가 1/4 π 및 3/4 π일 때, 열전달 값은 각각 2%, 116%증가함을 확인하였다.

다국어 초록 (Multilingual Abstract)

Heat transfer is an important aspect to consider when designing systems in various industries, and many researchers have introduced vortex generators to improve the heat transfer. In the case of a rigid vortex generator, energy loss is generated owing to a high pressure drop. In recent years, numerous studies have been conducted to improve heat transfer using a flexible vortex generator. In this study, an asymmetric inclined flexible flag was adopted as the vortex generator and an immersed boundary method was used to consider the fluid-flexible body interaction. When the bending rigidity of the flexible vortex generator was constant, the fluttering motion of the vortex generator increased as the inclination angle increased, and vortex structures were produced by the fluttering motion, thereby increasing the heat transfer. When the inclination angles were 45° and 135°, the heat transfer was observed to be increased by 2% and 116%, respectively.

목차 (Table of Contents)

• 초록
• Abstract
• 1. 서론
• 2. 수치 방법
• 3. 결과 및 고찰
• 4. 결론
• 참고문헌(References)

참고문헌 (Reference)

1 Fiebig, M., "Structure of Velocity and Temperature Fields in Laminar Channel Flows with Longitudinal Vortex Generators" 15 (15): 281-302, 1989

2 Park, S. G., "Simulation of Fluid-Flexible Body Interaction with Heat Transfer" 110 : 20-33, 2017

3 Huang, W. -X., "Simulation of Flexible Filaments in a Uniform Flow by the Immersed Boundary Method" 226 (226): 2206-2228, 2007

4 Goldstein, D., "Modeling a No-slip Flow Boundary with an External Force Field" 105 (105): 354-366, 1993

5 Park, S. G., "Heat Transfer Enhancement by a Wall-mounted Flexible Vortex Generator with an Inclination Angle" 148 : 2020

6 Fernandez, J. L., "Heat Transfer Enhancement by Means of Flag-type Insert in Tubes" 30 (30): 2603-2609, 1987

7 Lee, J. B., "Heat Transfer Enhancement by Flexible Flags Clamped Vertically in a Poiseuille Channel Flow" 107 : 391-402, 2017

8 Lee, J. B., "Heat Transfer Enhancement by Asymmetrically Clamped Flexible Flags in a Channel Flow" 116 : 1003-1015, 2018

9 Soti, A. K., "Flow-induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement" 84 : 1070-1081, 2015

10 Tiggelbeck, S., "Flow Structure and Heat Transfer in a Channel with Multiple Longitudinal Vortex Generators" 5 (5): 425-436, 1992

11 Dong, S., "Flow Past a Trapezoidal Tab" 510 : 219-242, 2004

12 Park, S. G., "Enhancement of Heat Transfer by a Selfoscillating Inverted Flag in a Poiseuille Channel Flow" 96 : 362-370, 2016

13 Herrault, F., "Cooling Performance of Micromachined Self-oscillating Reed Actuators in Heat Transfer Channels with Integrated Diagnostics" 1217-1220, 2012