Application of the Three-Parameter Differential Model of Turbulence for Solving Problems of Flow and Heat Transfer in Channels of Variable Cross-Section. Part 1

2021 ◽  
Vol 12 (1) ◽  
pp. 21-30
Author(s):  
V. G. Lushchik ◽  
◽  
M. S. Makarova ◽  
A. I. Reshmin ◽  
◽  
...  

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 first part the results of studies of mixed convection in vertical pipes under conditions of stable and unstable stratification, as well as flows in channels with permeable walls in the presence of blowing or suction on the wall, are presented.

2021 ◽  
Vol 12 (2) ◽  
pp. 89-106
Author(s):  
V. G. Lushchik ◽  
◽  
M. S. Makarova ◽  
A. I. Reshmin ◽  
◽  
...  

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.


2011 ◽  
Vol 243-249 ◽  
pp. 4935-4938
Author(s):  
Li Li ◽  
Xiao Ze Du

The heat transfer characteristic through periodical variable cross-section passage is studied with numerical scheme. The results in multi-period variable cross-section channel show that the heat transfer enhancement can be obtained by forming flow destabilization at large Reynolds number. The parameters include pressure, velocity, temperature in the channel are symmetric about central line at low Reynolds number, then change to asymmetric at high Reynolds number. The variations occur firstly at the downstream near outlet of the channel and move upstream, which could improve the fluid mixing to increase the enhancement of heat transfer in channel.


2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.


1980 ◽  
Vol 102 (2) ◽  
pp. 285-291 ◽  
Author(s):  
G. Yee ◽  
R. Chilukuri ◽  
J. A. C. Humphrey

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.


2009 ◽  
pp. n/a-n/a
Author(s):  
M. Alipanah ◽  
D.D. Ganji ◽  
E. Farnad ◽  
K. Babaei

Sign in / Sign up

Export Citation Format

Share Document