Numerical study of laminar mixed convection in the entrance region of a helical pipe with uniform wall temperature

2001 ◽  
pp. 1033-1036
Author(s):  
B. Zheng ◽  
C.X. Lin ◽  
M.A. Ebadian
Keyword(s):  
Mixed Convection ◽  
Wall Temperature ◽  
Numerical Study ◽  
Entrance Region ◽  
Uniform Wall Temperature ◽  
Laminar Mixed Convection ◽  
Helical Pipe ◽  
Uniform Wall

Numerical Study of Circular Tube inserted Arc Belt on Fluid Flow and Heat Transfer under Laminar Flow

2013 ◽  
Vol 561 ◽  
pp. 460-465
Author(s):  
Dong Hui Zhang ◽  
Jiao Gao
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Laminar Flow ◽  
Wall Temperature ◽  
Circular Tube ◽  
Numerical Study ◽  
Resistance Coefficient ◽  
Uniform Wall Temperature ◽  
Flow And Heat Transfer ◽  
Uniform Wall

The objective of this paper is to study the characteristic of a circular tube with a built-in arc belt on fluid flow and heat transfer in uniform wall temperature flows. Numerical simulations for hydrodynamically laminar flow was direct ran at Re between 600 and 1800. Preliminary results on velocity and temperature statistics for uniform wall temperature show that, arc belt can swirl the pipe fluid, so that the fluid at the center of the tube and the fluid of the boundary layer of the wall can mix fully, and plays the role of enhanced heat transfer, but also significantly increases the resistance of the fluid and makes the resistance coefficient of the enhanced tube greater than smooth tube. The combination property PEC is all above 1.5.

Laminar Mixed Convection in the Entrance Region of a Helical Pipe

1999 ◽  
Author(s):  
B. Zheng ◽  
C. X. Lin ◽  
M. A. Ebadian
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Control Volume ◽  
Three Dimensional ◽  
Entrance Region ◽  
Temperature Fields ◽  
Uniform Structure ◽  
Buoyancy Effect ◽  
Laminar Mixed Convection ◽  
Helical Pipe

Abstract A fully elliptic numerical study is performed to investigate the buoyancy-affected, three-dimensional laminar flow and heat transfer in the entrance region of a helical pipe at a constant wall temperature. The Control Volume Method with second-order accuracy is used to numerically solve the three-dimensional fully elliptic governing equations for the problem. The O-type non-uniform structure grid system is adopted to discretize the computation domain (two complete turns of a helical pipe) in this study. The Bossinesq approximation is applied to deal with the buoyancy effect caused directly by density difference. The developments of flow and temperature fields, profiles and characteristics at different Gr/Re2 are given and discussed. The computed results reveal that the entrance region of heat transfer is increased rapidly when buoyancy force is considered. In the meantime, the buoyancy effect on the average Nusselt number and friction factor is greater at the entrance region of the helical pipe, but it gradually becomes weaker further downstream.

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