Numerical Study on the Flow Characteristic in Periodical Variable Cross-Section Channel

2011 ◽  
Vol 250-253 ◽  
pp. 3245-3248
Author(s):  
Li Li ◽  
Xiao Ze Du

The flow characterizations through periodical variable cross-section passage are performed by numerical simulations in the one wavelength passage with periodic inlet and outlet boundary conditions. The flow patterns through the transient method in the passage show the steady characteristic at low Reynolds number, and the unsteady characteristics include either occurrence or development of self-sustained oscillations as the increasing of Reynolds number. As a consequence of these flow characteristics, the fluid mixing between the core flow and vortexes in trough or crest in channel can be improved to increase the heat transfer.

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.


2012 ◽  
Vol 18 (6) ◽  
pp. 773-782 ◽  
Author(s):  
Małgorzata Meissner ◽  
Piotr Ruta

The forced vibrations of a curved-in-plane nonprismatic beam with a variable cross section and any curvature, generated by a load moving at a variable velocity are analyzed. Approximation with Chebyshev series and a generalized eigentransformation were used to solve the system of the partial differential equations describing the considered problem. The derived equations in their final form enable one to determine displacement and rotation functions for any beam. In order to verify the derived formulas the eigenproblem solution (used in the eigentransformation method) was compared with the one obtained by the finite element method.


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.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Alexander Lopato ◽  
Pavel Utkin

The work is dedicated to the numerical study of detonation wave initiation and propagation in the variable cross-section axisymmetric channel filled with the model hydrogen-air mixture. The channel models the large-scale device for the utilization of worn-out tires. Mathematical model is based on two-dimensional axisymmetric Euler equations supplemented by global chemical kinetics model. The finite volume computational algorithm of the second approximation order for the calculation of two-dimensional flows with detonation waves on fully unstructured grids with triangular cells is developed. Three geometrical configurations of the channel are investigated, each with its own degree of the divergence of the conical part of the channel from the point of view of the pressure from the detonation wave on the end wall of the channel. The problem in consideration relates to the problem of waste recycling in the devices based on the detonation combustion of the fuel.


Sign in / Sign up

Export Citation Format

Share Document