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Performance intensification of turbulent flow through heat exchanger tube using double V-cut twisted tape inserts

Nakhchi, M. E ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.1016/j.cep.2019.107533
  3. Publisher: Elsevier B.V , 2019
  4. Abstract:
  5. This paper aims to present a numerical model for heat transfer intensification in a heat exchanger tube equipped with novel double V-cut twisted tape. The effects of different cut ratios (0.6 < b/c<1.8)on the turbulent flow characteristics and thermal performance of the system are investigated over the Reynolds number range from 5000 to 15,000. The accuracy of (RNG)k-ε turbulence model used in the present study is validated by comparing with experimental results. The tube equipped with double V-cut twisted tape shows improved thermal performance in comparison with conventional twisted tape. This improvement is due to the additional vortex flow induced by the V-cuts which leads to more effective thermal boundary layer disruption and thus intensifies the heat transfer rate. There are 48.0%, 64.3%, 86.0%, and 117.4% enhancement in the heat transfer rate by using double V-cut twisted tape with b/c = 0.6, 1, 1.4, 1.8 in comparison with the conventional twisted tape. The maximum thermal performance factor of 1.83 is obtained by using the heat exchanger tube with the double V-cut twisted-tape with b/c = 1.8 and y/w = 3 at the Reynolds number of 5000. © 2019 Elsevier B.V
  6. Keywords:
  7. Double V-cut twisted tape ; Friction factor ; Heat exchanger ; Performance intensification ; Atmospheric thermodynamics ; Boundary layers ; Heat transfer ; Reynolds number ; Turbulence models ; Turbulent flow ; Vortex flow ; Friction factors ; Heat transfer intensifications ; K-epsilon turbulence model ; Thermal boundary layer ; Thermal performance factors ; Twisted tapes ; Vortex generation ; Heat exchangers
  8. Source: Chemical Engineering and Processing - Process Intensification ; Volume 141 , 2019 ; 02552701 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0255270119301369