scholarly journals Developing Flow and Heat Transfer in Strongly Curved Ducts of Rectangular Cross Section

1980 ◽  
Vol 102 (2) ◽  
pp. 285-291 ◽  
Author(s):  
G. Yee ◽  
R. Chilukuri ◽  
J. A. C. Humphrey
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Numerical Study ◽  
Rectangular Cross Section ◽  
Flow And Heat Transfer ◽  
Computational Mesh ◽  
Developing Flow ◽  
Duct Geometry ◽  
Curved Ducts

A numerical study of heat transfer in 90 deg, constant cross section curved duct, steady, laminar, flow is presented. The work is aimed primarily at characterizing the effects on heat transfer of duct geometry and entrance conditions of velocity and temperature by considering, especially, the role of secondary motions during the developing period of the flow. Calculations are based on fully elliptic forms of the transport equations governing the flow. They are of engineering value and are limited in accuracy only by the degree of computational mesh refinement. A comparison with calculations based on parabolic equations shows how the latter can lead to erroneous results for strongly curved flows. Buoyant effects are excluded from the present study so that, strictly, the results apply to heat transfer flows in the absence of gravitational forces such as arise in spacecraft.

Fluid Flow and Heat Transfer in Microchannels With Rectangular Cross Section

2003 ◽  
Author(s):  
Jung-Yeul Jung ◽  
Ho-Young Kwak
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Transfer Coefficients ◽  
Forced Convective Heat Transfer ◽  
Heat Transfer Coefficients ◽  
Flow And Heat Transfer ◽  
Convective Heat Transfer Coefficients ◽  
Factor Constant

Forced convective heat transfer coefficients and friction factor for flow of water and FC-72 in microchannels with a rectangular cross section were measured. An integrated microsystem consisting of five microchannels on one side and a localized heater and seven polysilicon temperature sensors along the selected channels on the other side was fabricated by using a double side polished silicon wafer. For the microchannels tested, the friction factor constant C = f ReDh obtained are values between 35.7 and 81.9, which are close to the theoretical value of 57.0. The measured Nusselt number in the laminar regime tested could be correlated by a correlation, Nu = A ReDh1.37 Pr1/3 where A is the value between 0.000 454 and 0.000 646.

Application of the Three-Parameter Differential Model of Turbulence for Solving Problems of Flow and Heat Transfer in Channels of Variable Cross-Section. Part 2

2021 ◽  
Vol 12 (2) ◽  
pp. 89-106
Author(s):  
V. G. Lushchik ◽  
◽  
M. S. Makarova ◽  
A. I. Reshmin ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Numerical Study ◽  
Narrow Channel ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Differential Model ◽  
Heat Transfer Intensification ◽  
Flow And Heat Transfer ◽  
Shear Turbulence

A description of the method of numerical study in the approximation of a narrow channel of the problems of flow and heat transfer in flat and circular channels of variable cross-section using a differential three-parameter model of shear turbulence is presented. The main results of numerous studies using the proposed method are described, one of the goals of which was to substantiate the possibility of using the narrow channel approximation. This review study is carried out in two parts. In the second part the results of the study of laminarization during flow in the con-fuser and the pipe, heat transfer intensification during flow in diffusers and in a plate heat exchanger with diffuser channels are presented.

Experimental and Numerical Study on Flow Heat Transfer in Microchannels

2006 ◽  
Author(s):  
Jiang-Tao Liu ◽  
Yong Tian ◽  
Xiao-Feng Peng
Keyword(s):  
Heat Transfer ◽  
Liquid Flow ◽  
Numerical Study ◽  
Rectangular Cross Section ◽  
Numerical Approach ◽  
Cooling Capacity ◽  
Silicon Substrates ◽  
Entry Length ◽  
Flow And Heat Transfer ◽  
Series Of Experiments

An investigation was conducted on liquid flow and heat transfer in partially heated microchannels etched on the surface of silicon substrates. The rectangular cross-section channels had a hydraulic diameter of 100 microns. A series of experiments were carried out at different liquid flow rates and heating power. A numerical approach was made for single-phase liquid flow in the microchannels. A laminar flow model was employed in the simulation. Solid-fluid coupled thermal energy model was proposed to solve the conjugate heat transfer in the fluid and solid domains. The comparison of simulations with the experiment results shows good agreement. High cooling capacity was found in present study compared with the available data, indicating strong entry-length effect.

Numerical Study of Developing Flow and Heat Transfer in a Wavy Passage

1999 ◽  
Vol 121 (4) ◽  
pp. 713-719 ◽  
Author(s):  
K. Stone ◽  
S. P. Vanka
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Numerical Study ◽  
Spatial Location ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
The Core ◽  
Flow And Heat Transfer ◽  
Developing Flow ◽  
Energy Equations

Developing flow and heat transfer in a wavy passage are studied using a numerical scheme that solves the two-dimensional unsteady flow and energy equations. Calculations are presented for a wavy channel consisting of 14 waves. Time-dependent simulations have been performed for several Reynolds numbers. At low Reynolds numbers, the flow is steady in the complete channel. As the Reynolds number is progressively increased, the flow becomes unsteady. As a result of the unsteadiness, there is increased mixing between the core and the wall fluids, thereby increasing the heat transfer rate. With further increase in Reynolds number, the flow becomes unsteady at a much earlier spatial location.

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