ANALYSIS OF CONJUGATE MIXED CONVECTION-CONDUCTION HEAT TRANSFER IN A VERTICAL HEAT GENERATING CYLINDER IMMERSED IN POWER-LAW FLUIDS

2013 ◽  
Vol 31 (02) ◽  
pp. 61-68
Author(s):  
R. Kouhikamali ◽  
S. Abadi ◽  
S. Nia ◽  
S. Mohammadi
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Power Law ◽  
Conduction Heat Transfer ◽  
Power Law Fluids ◽  
Vertical Heat

Stratified Shear-Thinning Fluid Flow Past Tandem Cylinders in the Presence of Mixed Convection Heat Transfer with a Channel-Confined Configuration

2021 ◽  
Author(s):  
Ajay Raj Dwivedi ◽  
Amit Dhiman ◽  
Aniruddha Sanyal
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Power Law ◽  
Shear Thinning ◽  
Thermal Parameters ◽  
Maximum Heat ◽  
Critical Spacing ◽  
Maximum Heat Transfer ◽  
Gap Ratio ◽  
Power Law Fluids

Abstract The article examines the consequence of thermal buoyancy-driven cross-flow and heat transfer for shear-thinning power-law fluids on the tandem orientation of two cylinders. Finite volume methodology is used to investigate the effect of the gap ratio (2.5 ≤ S/D ≤ 5.5), power-law index (0.2 ≤ n ≤ 1) and Richardson number (0 ≤ Ri ≤ 1) on flow and thermal output parameters at Reynolds number Re ≤ 100 and Prandtl number Pr ≤ 50 in a confined channel. An unprecedented jump has been witnessed in the flow/thermal parameters at the critical gap ratio (critical spacing). At forced convection (Ri ≤ 0), this critical spacing keeps on increasing with shear-thinning character, from S/D = 3.9 (at n = 1) to 4.9 (at n = 0.2). On the contrary, an increase in shear-thinning characteristic leads to a decrease in critical spacing from S/D = 3.9 (at n = 1) to 2.8 (at n = 0.4) for Ri = 1 (mixed convection). The heat transfer rate increases with shear-thinning behavior, with a maximum heat transfer, noted at n = 0.2. A higher unprecedented increment for flow/thermal parameters is seen at critical spacing for the downstream cylinder than the upstream cylinder. At the highest gap ratio, the output parameters for the upstream cylinder approximate that of an isolated cylinder. The time-variant fluctuations in lift coefficients for a shear-thinning flow in a tandem arrangement provide a new understanding of co-shedding and extended body flow regimes.

Mixed Convection Heat Transfer From a Square Cylinder to Power-Law Fluids in Cross-Flow

2006 ◽  
Author(s):  
N. Anjaiah ◽  
A. K. Dhiman ◽  
R. P. Chhabra
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Steady Flow ◽  
Power Law ◽  
Richardson Number ◽  
Square Cylinder ◽  
Flow And Heat Transfer ◽  
Power Law Fluids

Laminar mixed convection flow and heat transfer to power-law fluids from a square cylinder has been analyzed numerically in the steady flow regime. The full momentum and energy equations along with the Boussinesq approximation have been solved by using a SMAC implicit finite difference method implemented on an uniform staggered grid arrangement for the range of Reynolds number 5 to 40, power-law index 0.6 to 1.4, Prandtl number 1 to 10 and Richardson number 0 to 0.5 in both bounded and unbounded flow configurations. The wall effects have been studied for a fixed blockage ratio of 1/15. The effects of buoyancy on the flow and heat transfer characteristics of power-law fluids have been elucidated. It is found that the mixed convection can initiate an asymmetry in the flow and temperature fields even within the steady flow regime. The variation of drag coefficients, and of the Nusselt number have been reported for a range of values of the Reynolds number, Prandtl number and Richardson number for both shear thickening and shear thinning fluids.

Mixed Convection Heat Transfer to Power Law Fluids in Arbitrary Cross-Sectional Ducts

1989 ◽  
Vol 111 (2) ◽  
pp. 399-406 ◽  
Author(s):  
A. Lawal
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Mixed Convection ◽  
Power Law ◽  
Convection Heat Transfer ◽  
Local Heat Transfer ◽  
Convection Flow ◽  
Transfer Coefficients ◽  
Cross Sectional ◽  
Power Law Fluids

An analytical investigation of three-dimensional mixed convection flow and heat transfer to power-law fluids in horizontal arbitrary cross-sectional ducts is undertaken. The continuity equation and parabolic forms of the energy and momentum equations in rectangular coordinates are transformed into new orthogonal coordinates with the boundaries of the duct coinciding with the coordinate surfaces. The transformed equations are solved by the finite difference technique. The fluid enters the duct with constant velocity and temperature profiles with the wall of the duct subjected to constant temperature. Local heat transfer coefficients and pressure drop for several values of Gr/Re and power-law index n are computed for the triangular, square, trapezoidal, pentagonal, and circular ducts. The buoyancy force is found to increase both the Nusselt number and the pressure drop.

Forced convection heat transfer study of a blunt-headed cylinder in non-Newtonian power-law fluids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaspinder Kaur ◽  
Roderick Melnik ◽  
Anurag Kumar Tiwari
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Drag Coefficient ◽  
Power Law ◽  
Average Nusselt Number ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Total Drag ◽  
Shear Thinning Fluids ◽  
Power Law Fluids

Abstract In this present work, forced convection heat transfer from a heated blunt-headed cylinder in power-law fluids has been investigated numerically over the range of parameters, namely, Reynolds number (Re): 1–40, Prandtl number (Pr): 10–100 and power-law index (n): 0.3–1.8. The results are expressed in terms of local parameters, like streamline, isotherm, pressure coefficient, and local Nusselt number and global parameters, like wake length, drag coefficient, and average Nusselt number. The length of the recirculation zone on the rear side of the cylinder increases with the increasing value of Re and n. The effect of the total drag coefficient acting on the cylinder is seen to be higher at the low value of Re and its effect significant in shear-thinning fluids (n < 1). On the heat transfer aspect, the rate of heat transfer in fluids is increased by increasing the value of Re and Pr. The effect of heat transfer is enhanced in shear-thinning fluids up to ∼ 40% and it impedes it’s to ∼20% shear-thickening fluids. In the end, the numerical results of the total drag coefficient and average Nusselt number (in terms of J H −factor) have been correlated by simple expression to estimate the intermediate value for the new application.

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