Multi-objective optimization of the structure of triangular chevron channels

Document Type : Research Article

Authors

Department of mechanical engineering,Arak university of technology, Arak, Iran

Abstract

Chevron channels are one of the popular techniques that are extensively used in different heat exchangers such as plate heat exchangers and solar air heaters. Numerical studies were carried out on turbulent heat transfer and friction factor loss through a triangular chevron channel for a uniform wall heat flux 3000 W/m2 using air as a working fluid. The results of the average Nusselt number, friction factor and thermal enhancement factor in different phase shifts (ϕ) are presented. Reynolds number were varied from 10000 to 30000 and horizontal moving of the plates were horizontally moved with regards to each other (phase shift) at the range of 0° ≤ϕ≤180° whereas, distance between chevron surfaces was constant (D=5 mm). The channels with phase shift angle of ϕ = 18.28º, are the most attractive from the viewpoint of energy saving. The genetic algorithm optimization using non-dominated sorting genetic algorithm II showed that with increasing Reynolds number, Nusselt number increased and the thermal enhancement factor decreased. It also proved that ϕ=18.28º was the optimum phase shift. The results also indicated that the triangular chevron channels with (Dv=7.43mm) have maximum Nusselt number and thermal enhancement factor and minimum friction factor.

Keywords

Main Subjects


A.A.  Aziz.  Dellil,  B.A.  Jubran,  Turbulent flow and convective heat transfer in a wavy wall channel, Heat and Mass Transfer, 40 (2004) 793–799. 
[2] C.P. Yasar Islamoglu Numerical investigation of convective heat transfer and pressure drop in a corrugated heat exchanger channel, Applied Thermal Engineering, 24 (2004).
[3] S.E.-a.a.W. Changcharoen, Analysis of Turbulent Heat Transfer and Fluid Flow in Channels with Various Ribbed Internal Surfaces, Journal of Thermal Science, 20 (2011) 260-267.
[4] J.L.a. GongnanXie a, Phillip M. Ligrani b, BengtSunden, Flow structure and heat transfer in a square passage with offset mid-truncated ribs, International Journal of Heat and Mass Transfer, 71 (2014) 44-56.
[5] M.-J.P. Mi-Ae Moon, Kwang-Yong Kim, Evaluation of heat transfer performances of various rib shapes, International Journal of Heat and Mass Transfer, 71 (2014) 275-284.
[6] K.S. A. NajahAl-Shamani, H.A.Mohammed, SohifMat , MohdHafidzRuslan, Azher, M.Abed, Enhancement heat transfer characteristics in the channel with Trapezoidal rib–groove using nano fluids, Case Studies in Thermal Engineering, 5 (2015) 48-58.
[7] M.S. M. Khoshvaght-Aliabadi, M. Hesampour, O. Sartipzadeh, Experimental study on cooling performance of sinusoidal–chevron mini channel heat sink, Applied Thermal Engineering, 92 (2016) 50-61.
[8] M. Sakr, Convective heat transfer and pressure drop in V-chevron channel with different phase shifts, Heat Mass Transfer,, 51 (2015) 129-141.
[9] S.P. B. Bonhoff, J. Leusch, B.V. Johnson, J. Schabacker, A. Bolcs, Experimental and numerical study of developed flow and heat transfer in coolant channels with 45 degree ribs, Int. J. Heat Fluid Flow, 20 (1999) 311-319.
[10] E.S. A. Bejan, The optimal spacing of parallel plates cooled by forced convection, Int. J. Heat Mass Transfer, 35 (1992) 3259-3264.