평판 휜 열교환기의 열 수력학적 성능에 대한 고속 바이패스 영향의 수치적 연구

다국어 초록 (Multilingual Abstract)

The high-speed bypass effect on the heat exchanger performance has been investigated numerically. The plate-fin type heat exchanger was modeled using two-dimensional porous approximation for the fin region. Governing equations of mass, momentum, and energy equations for compressible turbulent flow were solved using ideal-gas assumption for the air flow. Various bypass-channel height were considered for Mach numbers ranging 0.25-0.65. Due to the existence of the fin in the bypass channel, the main flow tends to turn into the core region of the channel, which results in the distorted velocity profile downstream of the fin region. The boundary layer thickness, displacement thickness, and the momentum thickness showed the variation of mass flow through the fin region. The mass flow variation along the fin region was also shown for various bypass heights and Mach numbers. The volumetric entropy generation was used to assess the loss mechanism inside the bypass duct and the fin region. Finally, the correlations of the friction factor and the Colburn j-factor are summarized.

참고문헌 (Reference)

1 김영진, "항공기 가스터빈용 오일쿨러 해석을 위한 1 차원 열유동 네트워크 수치적 모델 개발 및 연구" 대한기계학회 38 (38): 915-924, 2014

2 서준호, "유동 방향으로 기울어진 사각 핀-휜 열교환기의 유동 및 열전달 특성에 대한 수치적 연구" 한국전산유체공학회 21 (21): 98-109, 2016

3 White, F.M., "Viscous fluid flow" 2016

4 Chapman, C.L, "Thermal performance of an Elliptical Pin Fin Heat sink" 1994

5 Jonsson, H., "Modeling of the thermal and hydraulic performance of plate fin, strip fin, and pin fin heat sinks – Influence of flow by-pass" 24 : 142-149, 2014

6 Shah, R.K., "Laminar flow forced convection in ducts" Academic Press, Inc 1978

7 Kim, S, "Investigation of high-speed bypass effect on the performance of the surface air oil heat exchanger for an aero engine" 77 : 321-334, 2014

8 Yun, J.Y., "Investigation of heat transfer characteristics on various kinds of fin-and-tube heat exchangers with interrupted surfaces" 42 : 2375-2385, 1998

9 Min, J.K, "High temperature heat exchanger studies for applications to gas turbines" 46 : 175-186, 2009

10 Shah, R.K., "Fundamentals of Heat Exchanger Design" J. Wiley 2003

11 Kang, H.J, "Experimental study on heat transfer and pressure drop characteristic of four types of plate fin-and-tube heat exchanger surfaces" 3 (3): 34-42, 1994

12 Jonsson, H., "Enhancement of the cooling performace of circular pin fin heat sinks under flow by-pass conditions" 425-432, 2002

13 Sata, T., "Development of Prediction Technique for Cooling Performance of Finned Heat Sink in Uniform Flow" 20 (20): 160-166, 1997

14 Outirba, B., "Development and Testing of Advanced Surface Oil Coolers for Aero-Engines"

15 Doo, J.H, "An investigation of crosscorrugated heat exchanger primary surfaces for advanced intercooled-cycle aero engines (Part-II: Design optimization of primary surface)" 61 : 138-148, 2013

16 Teng, H., "An extension of Darcy's law to non-Stokes flow in porous media" 55 : 2727-2735, 2000

17 Adams, J.C., "Advanced heat transfer surfaces for gas turbine heat exchangers" University of Oxford 2004

18 "ANSYS FLUENT 15.0 USER's guide"

19 Ko, J.A, "A study on the installation of the surface air-oil heat exchanger for the application to aero gas-turbine engine" 2013

20 Kim, M, "A numerical study on various pin fin shaped surface air oil heat exchangers for an aero gas-turbine engine" 93 : 637-652, 2016

21 Hasan, N., "A new flux-based scheme for compressible flows" 119 : 58-86, 2015