Numerical investigation of heat transfer and friction factor characteristics from in-line cam shaped tube bank in crossflow

2017 ◽  
Vol 110 ◽  
pp. 521-538 ◽  
Author(s):  
Chidanand K. Mangrulkar ◽  
Ashwinkumar S. Dhoble ◽  
Amey R. Deshmukh ◽  
Sachin A. Mandavgane
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Numerical Investigation ◽  
Tube Bank ◽  
Shaped Tube

scholarly journals Numerical Investigation of Heat Transfer and Friction Factor Characteristics in a Circular Tube Fitted with V-Cut Twisted Tape Inserts

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sami D. Salman ◽  
Abdul Amir H. Kadhum ◽  
Mohd S. Takriff ◽  
Abu Bakar Mohamad
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Numerical Investigation ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Twisted Tape ◽  
Maximum Heat ◽  
High Heat Transfer ◽  
Maximum Heat Transfer ◽  
Twist Ratio

Numerical investigation of the heat transfer and friction factor characteristics of a circular fitted with V-cut twisted tape (VCT) insert with twist ratio (y=2.93) and different cut depths (w=0.5, 1, and 1.5 cm) were studied for laminar flow using CFD package (FLUENT-6.3.26). The data obtained from plain tube were verified with the literature correlation to ensure the validation of simulation results. Classical twisted tape (CTT) with different twist ratios (y=2.93, 3.91, 4.89) were also studied for comparison. The results show that the enhancement of heat transfer rate induced by the classical and V-cut twisted tape inserts increases with the Reynolds number and decreases with twist ratio. The results also revealed that the V-cut twisted tape with twist ratioy=2.93and cut depthw=0.5 cm offered higher heat transfer rate with significant increases in friction factor than other tapes. In addition the results of V-cut twist tape compared with experimental and simulated data of right-left helical tape inserts (RLT), it is found that the V-cut twist tape offered better thermal contact between the surface and the fluid which ultimately leads to a high heat transfer coefficient. Consequently, 107% of maximum heat transfer was obtained by using this configuration.

A Two-Dimensional Numerical Investigation on Forced Convection in Channels With Transversal Ribs

2009 ◽  
Author(s):  
O. Manca ◽  
S. Nardini ◽  
D. Ricci
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Numerical Investigation ◽  
Forced Convection ◽  
Energy Use ◽  
Wall Turbulence ◽  
Transfer Coefficients ◽  
Pressure Drops ◽  
Heat Transfer Coefficients ◽  
High Heat Transfer

Conventional sources of energy have been depleting at an alarming rate, which makes future sustainable development of energy use very difficult. Thus, heat transfer enhancement technology plays an important role and it has been widely applied to many applications as in refrigeration, automotive, process industry and solar energy heater. Convective heat transfer can be enhanced passively by changing flow geometry, boundary conditions or by increasing thermal conductivity of the fluid. Another possibility for increasing heat transfer with gas is to employ extended surfaces. Transversal ribs in a channel work as fins, increasing the heat transfer area and break the laminar sub-layer creating local wall turbulence. The heat transfer rate is improved but pressure drops increased as well. In this paper a numerical investigation is carried out on forced convection in channels heated by a constant heat flux. Also conductive effects are taken into account. The fluid is air and properties are assumed as function of temperature and flow is turbulent. Ribs of the same material of the channel walls are introduced and several arrangements and shapes are analyzed. The investigation is accomplished by means of the Fluent code. Results are presented in terms of temperature and velocity fields, average heat transfer coefficients and friction factor profiles. The aim of this study is to find arrangement of ribs such to give high heat transfer coefficients and low pressure drops. The maximum Nusselt number and friction factor have been detected for dimensionless pitches equal, respectively, to 12 and 10 for square and rectangular ribs, 10 and 8, for triangular ones.

A Study About Performance Evaluation Criteria of Tube Banks With Various Shapes and Arrangements Using Numerical Simulation

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Amin Jodaei ◽  
Kamiar Zamzamian
Keyword(s):  
Heat Transfer ◽  
Performance Evaluation ◽  
Heat Exchangers ◽  
Three Dimensional ◽  
Evaluation Criteria ◽  
Cross Flow ◽  
Transfer Coefficients ◽  
Tube Bank ◽  
Shaped Tube ◽  
Tube Banks

Tube bank heat exchangers are designed to efficiently transfer heat between two fluids. Shapes and arrangements of tubes in heat exchangers have significant effects in heat transfer and pressure drop of fluid. In this study, the three-dimensional (3D) numerical investigation is performed to determine heat transfer coefficients, friction factor, and performance evaluation criteria (PEC) of cam-shaped tube banks in aerodynamic and inverse aerodynamic directions in the cross flow air and compared with those of elliptical tube banks in heat exchanger. The arrangements of tubes are aligned and staggered with longitudinal pitch of 44.88 mm and transverse pitch of 28.05 mm. Reynolds number in the range of 11,500–18,500 was used, and the tube surface temperature was fixed and considered 352 K. Results indicate the superior heat transfer of elliptical tube bank over the cam-shaped tube banks in inverse aerodynamic and aerodynamic directions in both arrangements. Moreover, the PEC of the cam-shaped tube banks with inverse aerodynamic and aerodynamic directions and elliptical tube bank in aligned arrangement are approximately 1.4, 1.1, and 1.6, respectively. The obtained results for staggered arrangements are also 1.5, 1.3, and 1.8, respectively.

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