Entrance region heat transfer with axial conduction in a cylindrical tube: Constant wall heat flux

1977 ◽  
Vol 20 (12) ◽  
pp. 2153
Author(s):  
B. J. Barr ◽  
C. L. Wiginton
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Cylindrical Tube ◽  
Wall Heat Flux ◽  
Entrance Region ◽  
Axial Conduction ◽  
Constant Wall Heat Flux

Heat Transfer of Power Law Fluid at Low Peclet Number Flow

1983 ◽  
Vol 105 (3) ◽  
pp. 542-549 ◽  
Author(s):  
Vi-Duong Dang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Power Law ◽  
Peclet Number ◽  
Wall Heat Flux ◽  
Power Law Fluid ◽  
Axial Conduction ◽  
Péclet Number ◽  
Constant Wall Heat Flux ◽  
Number Flow

An exact solution is presented for the temperature distribution and local Nusselt number of power law fluid in conduit at low Peclet number flow by considering axial conduction in both the upstream and the downstream regions while keeping the wall at constant temperature. Solutions are also reported for the parallel plate geometry for the aforementioned heat transfer condition and for constant wall heat flux boundary condition. The order of importance of axial conduction is established for different geometries and different boundary conditions. The effect of axial conduction is more significant when power law model index, s, increases for constant wall heat flux case, but the effect changes with Peclet number for constant wall temperature case.

A Historical Misperception on Calculating the Average Convection Coefficient in Tubes With Constant Wall Heat Flux

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Ted D. Bennett
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Exact Solutions ◽  
Wall Heat Flux ◽  
First Principle ◽  
Convection Coefficient ◽  
Parallel Plates ◽  
Historical Approach ◽  
First Principle Calculations ◽  
Constant Wall Heat Flux

The historical approach to averaging the convection coefficient in tubes of constant wall heat flux leads to quantitative errors in short tubes as high as 12.5% for convection into fully developed flows and 33.3% for convection into hydrodynamically developing flows. This mistake can be found in teaching texts and monographs on heat transfer, as well as in major handbooks. Using the correctly defined relationship between local and average convection coefficients, eight new correlations are presented for fully developed and developing flows in round tubes and between parallel plates for the constant wall heat flux condition. These new correlations are within 2% of exact solutions for fully developed flows and within 6% of first principle calculations for hydrodynamically developing flows.

Effect of Wall Electrical Conductance on Magnetohydrodynamic Heat Transfer in a Channel

1963 ◽  
Vol 85 (4) ◽  
pp. 371-377 ◽  
Author(s):  
J. T. Yen
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Boundary Conditions ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Electrical Conductance ◽  
Wall Heat Flux ◽  
Constant Wall Heat Flux

Effect of wall electrical conductance on laminar fully developed magnetohydrodynamic heat transfer in a channel with constant wall heat flux and exact magnetohydrodynamic boundary conditions are investigated. For channels with insulated walls, viscous dissipation is more important than joule heating for all Ec and M. For sufficiently large wall conductance, viscous dissipation is dominated by joule heating for all Ec, if M is large enough; both are in turn dominated by wall heat flux if Ec is large enough for all M. These and other conclusions are discussed in this paper.

scholarly journals HEAT TRANSFER OF LAMINAR FLOW IN VERTICAL TUBES WITH CONSTANT WALL HEAT FLUX

1968 ◽  
Vol 1 (2) ◽  
pp. 120-124 ◽  
Author(s):  
NOBUO MITSUISHI ◽  
OSAMU MIYATAKE ◽  
MITSURU YANAGIDA
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Laminar Flow ◽  
Wall Heat Flux ◽  
Constant Wall Heat Flux ◽  
Vertical Tubes

scholarly journals Axisymmetric stagnation-point flow and heat transfer of nanofluid impinging on a cylinder with constant wall heat flux

2019 ◽  
Vol 23 (5 Part B) ◽  
pp. 3153-3164 ◽  
Author(s):  
Hamid Mohammadiun ◽  
Vahid Amerian ◽  
Mohammad Mohammadiun ◽  
Iman Khazaee ◽  
Mohsen Darabi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Velocity Field ◽  
Stagnation Point ◽  
Base Fluid ◽  
Fluid Velocity ◽  
Wall Heat Flux ◽  
Flow And Heat Transfer ◽  
Constant Wall Heat Flux ◽  
Fluid Velocity Field

The steady-state, viscous flow and heat transfer of nanofluid in the vicinity of an axisymmetric stagnation point of a stationary cylinder with constant wall heat flux is investigated. The impinging free-stream is steady and with a constant strain rate, k ?. Exact solution of the Navier-Stokes equations and energy equation are derived in this problem. A reduction of these equations is obtained by use of appropriate transformations introduced in this research. The general self-similar solution is obtained when the wall heat flux of the cylinder is constant. All the previous solutions are presented for Reynolds number Re = k ?a2/2n f ranging from 0.1 to 1000, selected values of heat flux and selected values of particle fractions where a is cylinder radius and n f is kinematic viscosity of the base fluid. For all Reynolds numbers, as the particle fraction increases, the depth of diffusion of the fluid velocity field in radial direction, the depth of the diffusion of the fluid velocity field in z-direction, shear-stresses and pressure function decreases. However, the depth of diffusion of the thermal boundary-layer increases. It is clear by adding nanoparticles to the base fluid there is a significant enhancement in Nusselt number and heat transfer.

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