0
Research Papers

# Effect of Longitudinal Vortex Generator Location on Thermoelectric-Hydraulic Performance of a Single-Stage Integrated Thermoelectric Power Generator

[+] Author and Article Information
Samruddhi Deshpande

Department of Mechanical Engineering,
Virginia Tech,
Blacksburg, VA 24061
e-mail: sdesh@vt.edu

Bharath Viswanath Ravi

Department of Mechanical Engineering,
Virginia Tech,
Blacksburg, VA 24061
e-mail: bharvish@vt.edu

Jaideep Pandit

Department of Mechanical Engineering,
Virginia Tech,
Blacksburg, VA 24061
e-mail: jpandit@vt.edu

Ting Ma

Department of Mechanical Engineering,
Xi'an Jiaotong University,
Xi'an 710049, Shaanxi, China
e-mail: mating715@mail.xjtu.edu.cn

Scott Huxtable

Department of Mechanical Engineering,
Virginia Tech,
Blacksburg, VA 24061
e-mail: huxtable@vt.edu

Department of Mechanical Engineering,
Virginia Tech,
Blacksburg, VA 24061

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received May 15, 2017; final manuscript received March 15, 2018; published online June 14, 2018. Assoc. Editor: Samuel Sami.

J. Thermal Sci. Eng. Appl 10(5), 051016 (Jun 14, 2018) (8 pages) Paper No: TSEA-17-1163; doi: 10.1115/1.4040033 History: Received May 15, 2017; Revised March 15, 2018

## Abstract

Vortex generators have been widely used to enhance heat transfer in various heat exchangers. Out of the two types of vortex generators, transverse vortex generators and longitudinal vortex generators (LVGs), LVGs have been found to show better heat transfer performance. Past studies have shown that the implementation of these LVGs can be used to improve heat transfer in thermoelectric generator systems. Here, a built in module in COMSOL Multiphysics® was used to study the influence of the location of LVGs in the channel on the comprehensive performance of an integrated thermoelectric device (TED). The physical model under consideration consists of a copper interconnector sandwiched between p-type and n-type semiconductors and a flow channel for hot fluid in the center of the interconnector. Four pairs of LVGs are mounted symmetrically on the top and bottom surfaces of the flow channel. Thus, using numerical methods, the thermo-electric-hydraulic performance of the integrated TED with a single module is examined. By fixing the material size D, the fluid inlet temperature $Tin$, and attack angle β, the effects of the location of LVGs and Reynolds number were investigated on the heat transfer performance, power output, pressure drop, and thermal conversion efficiency. The location of LVGs did not have significant effect on the performance of TEGs in the given model. However, the performance parameters show a considerable change with Reynold's number and best performance is obtained at Reynold number of Re = 500.

<>

## References

Yang, J. , 2005, “ Potential Applications of Thermoelectric Waste Heat Recovery in the Automotive Industry,” 24th International Conference on Thermoelectrics (ICT 2005), Clemson, SC, June 19–23, pp. 170–174.
Espinosa, N. , Lazard, M. , Aixala, L. , and Scherrer, H. , 2010, “ Modeling a Thermoelectric Generator Applied to Diesel Automotive Heat Recovery,” J. Electron. Mater., 39(9), pp. 1446–1455.
Saqr, K. M. , Mansour, M. K. , and Musa, M. N. , 2008, “ Thermal Design of Automobile Exhaust Based Thermoelectric Generators: Objectives and Challenges,” Int. J. Automot. Technol., 9(2), pp. 155–160.
Zorbas, K. T. , Hatzikraniotis, E. , and Paraskevopoulos, K. M. , 2007, “ Power and Efficiency Calculation in Commercial TEG and Application in Wasted Heat Recovery in Automobile,” Fifth European Conference on Thermoelectrics (ECT), Odessa, Ukraine, Sept. 10–12, pp. 1–4.
Pandit, J. , Thompson, M. , Ekkad, S. V. , and Huxtable, S. , 2013, “ Experimental Investigation of Heat Transfer Across a Thermoelectric Generator for Waste Heat Recovery From Automobile Exhaust,” ASME Paper No. HT2013-17438.
Hsiao, Y. Y. , Chang, W. C. , and Chen, S. L. , 2010, “ A Mathematic Model of Thermoelectric Module With Applications on Waste Heat Recovery From Automobile Engine,” Energy, 35(3), pp. 1447–1454.
Wang, X. D. , Huang, Y. X. , Cheng, C. H. , Ta-Wei Lin, D. , and Kang, C. H. , 2012, “ A Three-Dimensional Numerical Modeling of Thermoelectric Device With Consideration of Coupling of Temperature Field and Electric Potential Field,” Energy, 47(1), pp. 488–497.
Chen, M. , Rosendahl, L. A. , and Condra, T. , 2011, “ A Three-Dimensional Numerical Model of Thermoelectric Generators in Fluid Power Systems,” Int. J. Heat Mass Transf., 54(1–3), pp. 345–355.
Reddy, B. V. K. , Barry, M. , Li, J. , and Chyu, M. K. , 2014, “ Convective Heat Transfer and Contact Resistances Effects on Performance of Conventional and Composite Thermoelectric Devices,” ASME J. Heat Transfer, 136(10), p. 101401.
Reddy, B. V. K. , Barry, M. , Li, J. , and Chyu, M. K. , 2014, “ Thermoelectric-Hydraulic Performance of a Multistage Integrated Thermoelectric Power Generator,” Energy Convers. Manag., 77, pp. 458–468.
Reddy, B. V. K. , Barry, M. , Li, J. , and Chyu, M. K. , 2013, “ Thermoelectric Performance of Novel Composite and Integrated Devices Applied to Waste Heat Recovery,” ASME J. Heat Transfer, 135(3), p. 031706.
Pandit, J. , Thompson, M. , Ekkad, S. V. , and Huxtable, S. T. , 2014, “ Effect of Pin Fin to Channel Height Ratio and Pin Fin Geometry on Heat Transfer Performance for Flow in Rectangular Channels,” Int. J. Heat Mass Transfer, 77, pp. 359–368.
Wang, Q. , Chen, Q. , Wang, L. , Zeng, M. , Huang, Y. , and Xiao, Z. , 2007, “ Experimental Study of Heat Transfer Enhancement in Narrow Rectangular Channel With Longitudinal Vortex Generators,” Nucl. Eng. Des., 237(7), pp. 686–693.
Wu, J. M. , and Tao, W. Q. , 2008, “ Numerical Study on Laminar Convection Heat Transfer in a Rectangular Channel With Longitudinal Vortex Generator—Part A: Verification of Field Synergy Principle,” Int. J. Heat Mass Transfer, 51(5–6), pp. 1179–1191.
Chen, C. , Teng, J. T. , Cheng, C. H. , Jin, S. , Huang, S. , Liu, C. , Lee, M. T. , Pan, H. H. , and Greif, R. , 2014, “ A Study on Fluid Flow and Heat Transfer in Rectangular Microchannels With Various Longitudinal Vortex Generators,” Int. J. Heat Mass Transf., 69, pp. 203–214.
Tiggelbeck, S. , Mitra, N. K. , and Fiebig, M. , 1993, “ Experimental Investigations of Heat Transfer Enhancement and Flow Losses in a Channel With Double Rows of Longitudinal Vortex Generators,” Int. J. Heat Mass Transf., 36(9), pp. 2327–2337.
Wu, J. M. , and Tao, W. Q. , 2008, “ Numerical Study on Laminar Convection Heat Transfer in a Channel With Longitudinal Vortex Generator. Part B: Parametric Study of Major Influence Factors,” Int. J. Heat Mass Transfer, 51(13–14), pp. 3683–3692.
Ma, T. , Pandit, J. , Ekkad, S. V. , Huxtable, S. T. , and Wang, Q. , 2015, “ Simulation of Thermoelectric-Hydraulic Performance of a Thermoelectric Power Generator With Longitudinal Vortex Generators,” Energy, 84, pp. 695–703.
Reddy, B. V. K. , Barry, M. , Li, J. , and Chyu, M. K. , 2012, “ Three-Dimensional Multiphysics Coupled Field Analysis of an Integrated Thermoelectric Device,” Numer. Heat Transf. Part A, 62(12), pp. 933–947.
Sohankar, A. , and Davidson, L. , 2001, “ Effect of Inclined Vortex Generators on Heat Transfer Enhancement in a Three-Dimensional Channel,” Numer. Heat Transf. Part A, 39(5), pp. 433–448.
Lesage, F. J. , Sempels, É. V. , and Lalande-Bertrand, N. , 2013, “ A Study on Heat Transfer Enhancement Using Flow Channel Inserts for Thermoelectric Power Generation,” Energy Convers. Manag., 75, pp. 532–541.

## Figures

Fig. 1

Thermoelectric leg model with LVGs. The hot gas passes through the center of the interconnector, and the LVGs are used to increase heat transfer from the gas to the thermoelectric legs.

Fig. 2

Schematic diagram of the placement of LVGs in the flow channel

Fig. 3

Numerical simulation domain and boundary conditions

Fig. 4

Grid independence for heat input

Fig. 5

Grid independence for power output

Fig. 6

Grid independence for pressure

Fig. 7

Power output as a function of Reynolds number for a benchmark case. The results are nearly identical to those from Reddy et al. [19]

Fig. 8

Heat input as a function of Reynolds number in comparison with results from Reddy et al. [19]

Fig. 9

Comparison between heat input with a model with LVGs and same model without LVGs. The results enhancement in heat transfer due to LVGs.

Fig. 10

Heat input as a function of the distance, s, that the LVG is placed from the leading edge of the channel

Fig. 11

Velocity profile of the middle cross sections of the thermoelectric modules for various LVG locations at Re = 500

Fig. 12

Pressure drop as a function of the LVG distance from the leading edge of the channel

Fig. 13

Pressure drop across the whole fluid domain along the central line

Fig. 14

Net power output of the thermoelectric generator as a function of the LVG distance from the leading edge of the channel

Fig. 15

Ratio of pumping power to power output as a function of the LVG distance from the leading edge of the channel. The increase in pumping power is only a small fraction of the total thermoelectric power produced.

Fig. 16

Thermal efficiency of the thermoelectric generator as a function of the LVG distance from the leading edge of the channel

Fig. 17

Heat input as a function of distance from the leading edge of the channel for pitch distances of 1 and 2 mm and a Reynolds number of 400

Fig. 18

Pressure drop as a function of distance from the leading edge of the channel for pitch distances of 1 and 2 mm and a Reynolds number of 400

Fig. 19

Power output as a function of distance from the leading edge of the channel for pitch distances of 1 and 2 mm and a Reynolds number of 400

Fig. 20

Thermal efficiency as a function of distance from the leading edge of the channel for pitch distances of 1 and 2 mm and a Reynolds number of 400

## Errata

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections