Influence of Dimple Shapes on Turbulent Flow and Heat Transfer

Abstract

Abstract:

Abstract： Dimples are very effective structures to enhance heat transfer. Based on numerical simulations, this paper investigated the heat transfer and friction factor of sphere, eliptical, inclined eliptical and teardrop dimple. Comparisons of the heat transfer and friction factor results obtained by using the Relizable k-ε, SST, and Standard k-ω models with the experimental results indicate that the Standard k-ω model can best predict the flow and heat transfer in the dimpled channels. The heat transfer and flow structure characteristics in the four dimpled channels have been obtained and compared with each other for the Reynolds numbers of 8 500 to 60 000.The Matlab software is used in this paper to process the numerical data to get the heat transfer distribution along the streamwise direction. The study shows that compared to the flat channel, the sphere dimple enhances the heat transfer by 40% and the friction factor by 70%; the eliptical dimple enhances the heat transfer by 30% and the friction factor by 60%;the inclined eliptical dimple enhances the heat transfer by 40% and the friction factor by 60%; and the teardrop dimple enhances the heat transfer by 70% and the friction factor by 100%. Generally speaking, the teardrop dimple has the best heat transfer and overall performance.

Key words: dimple, vortex generator, gas turbine cooling, heat transfer, friction factor

CLC Number:

TK 47

FENG Yan,RAO Yu,LI Bo. Influence of Dimple Shapes on Turbulent Flow and Heat Transfer[J]. Journal of Shanghai Jiaotong University, 2015, 49(05): 614-619.

References

［1］Han J C, Dutta S, Ekkad S. Gas turbine heat transfer and cooling technology［M］. England: Taylor and Francis, 2001.

［2］Rao Y, Zang S S. Flow and heat transfer characteristics in latticework cooling channels with dimple vortex generators［J］. ASME J Heat Transfer, 2014,136 (2): 0210170210110.

［3］张翔，饶宇. 具有凹陷涡发生器的网格冷却结构内的流动和传热特性［J］. 航空动力学报，2013, 28（17）：15031509.

ZHANG Xiang, RAO Yu. Flow and heat transfer characteristics in latticework cooling structure with dimple vortex generators［J］. Journal of Aerospace Power, 2013, 28(17):15031509.

［4］Chyu M K, Yu Y, Ding H, et al. Concavity enhanced heat transfer in an internal cooling passage［C］∥International Gas Turbine and Aeroengine Congress and Exhibition. USA: ASME, 1997: V003T09A08087.

［5］Burgess N K, Ligrani P M. Effects of dimple depth on channel Nusselt numbers and friction factors［J］. ASME Journal Heat Transfer, 2005, 127(8): 839847.

［6］Ligrani P M, Harrison J L, Mahmood G I, et al. Flow structure due to dimple depression on a channel surface［J］. Physics Fluids, 2001, 13 (11): 34423451.

［7］Johann T, Nikolai K, Valery Z, et al. Flow structures and heat transfer on dimples in a staggered arrangement［J］. International Journal of Heat and Fluid Flow, 2012, 35 (1): 168175.

［8］Kim H M, Moon M A, Kim K Y. Multiobjective optimization of a cooling channel with staggered elliptic dimples［J］. Energy, 2011, 36 (5): 34193428

［9］Bunker R S, Donnellan K F. Heat transfer and friction factors for flows inside circular tubes with concavity surfaces［J］. ASME Journal of Turbomachinery, 200, 125 (4): 665672.

［10］Rao Y, Wan C, Zang S. An experimental and numerical study of the flow and heat transfer in channels with pin findimple combined arrays of different configurations［J］. ASME J Heat Transfer, 2012, 134 (12): 121901.

［11］Gee D L, Webb R L. Forced convection heat transfer in helically ribroughened tubes［J］. International Journal of Heat Mass Transfer, 1980, 23(8): 11271136.

[1]	MA Shasha, DING Shengjie, LIU Limin, ZHAO Changying, GU Hanyang, GONG Shuai. Micro-Scale Heat Transfer Characteristics of Evaporating Meniscus for Alkali Metals in High-Temperature Heat Pipes [J]. Journal of Shanghai Jiao Tong University, 2025, 59(5): 617-627.
[2]	CHEN Qinghua, WU Jiale, LU Yu, JI Jiadong, LIU Ping. Testing Method for Thermal Diffusivity of Solid Materials Based on Combined Boundary Conditions [J]. Journal of Shanghai Jiao Tong University, 2024, 58(8): 1201-1210.
[3]	CHEN Haitang^1,2 (陈海棠), HU Chengliang^1,2* (胡成亮), GONG Aijun³ (龚爱军), SHI Weibing³ (施卫兵), ZHAO Zhen^1,2 (赵震). Novel Blasting-Like Lubricating Process for Cold Extrusion [J]. J Shanghai Jiaotong Univ Sci, 2024, 29(2): 322-329.
[4]	HAN Xueyang, WU Lin, LIU Zhibing, YU Dongwei, KONG Xiangyi, ZHANG Dayong. Influence of Convection Heat Transfer of Tread Plate in Polar Environment [J]. Journal of Shanghai Jiao Tong University, 2024, 58(11): 1687-1697.
[5]	CHEN Erdong, GAO Zihang, WANG Kundong, LEI Huaming. Design of a Rapid Thermal Cycling System for Real-Time Fluorescent PCR with Zone Temperature Control [J]. Journal of Shanghai Jiao Tong University, 2023, 57(9): 1196-1202.
[6]	CHENG Xianda, ZHENG Haoran, YANG Xuesen, DONG Wei. Improved Thermal Network Method for Fuel Transient Temperature Prediction of High-Speed Aircrafts [J]. Journal of Shanghai Jiao Tong University, 2023, 57(6): 728-738.
[7]	XIA Yunsong, TAN Jianfeng, HAN Shui, GAO Jin’e. Optimization of Wind Turbine Vortex Generator Based on Back Propagation Neural Network [J]. Journal of Shanghai Jiao Tong University, 2023, 57(11): 1492-1500.
[8]	GU Bo, DU Zhongxing, ZENG Weijie, TIAN Zhen, ZHANG Zhiting. Flow Boiling Heat Transfer Coefficient and Frictional Pressure Drop Correlations for R32 [J]. Journal of Shanghai Jiao Tong University, 2023, 57(1): 45-54.
[9]	ZHANG Tianlun, WANG Kechen, ZHANG Xu, ZHOU Wenwu. Numerical Simulation Study on Effect of Fin Array on Impingement Heat Transfer Performance of Airfoil Surface [J]. Journal of Shanghai Jiao Tong University, 2023, 57(1): 55-65.
[10]	CAO Taichun, WU Gang, KONG Xiangyi, YU Dongwei, WU Lin, ZHANG Dayong. Influence of Convection Heat Transfer on Circular Tube Structure of Polar Marine Engineering Equipment [J]. Journal of Shanghai Jiao Tong University, 2023, 57(1): 17-23.
[11]	XIAO Kehua, LUO Jiahao, RAO Yu. Experiment on Wedge-Shaped Latticework Channel Cooling Applied in Aero Engine Gas Turbine Blade Trailing Edge [J]. Journal of Shanghai Jiao Tong University, 2022, 56(8): 1034-1042.
[12]	WU Wanghao, DUAN Xu, ZhANG Xin, CHEN Dan, XU Zhendong. Research on the Integrated Calculation Method of Aerodynamics and Heat Transfer for Hypersonic Blunt Body [J]. Air & Space Defense, 2022, 5(3): 87-92.
[13]	CHEN Qinghua, GAO Wei, SU Guoyong, GUAN Weijuan, QIN Ruxiang, JI Jiadong, MA Yangbin. Test of Thermo-Physical Property Parameters of Solid Material Based on Laser Point Heat Source Unsteady-State Heat Transfer Model [J]. Journal of Shanghai Jiao Tong University, 2021, 55(4): 471-479.
[14]	WANG Rui, XIAO Yao, GU Hanyang, YE Yanan. Numerical Simulation of Circumferential Non-Uniform Heat Transfer of Single-Phase Flow in Helical Pipes [J]. Journal of Shanghai Jiaotong University, 2020, 54(7): 688-696.
[15]	WANG Kai,XIA Tian,RAO Yu. Flow Characteristics and Heat Transfer of Swirl Cooling in Three-Pass Channel [J]. Journal of Shanghai Jiaotong University, 2020, 54(5): 481-489.