INTENSIFICATION AND STUDY OF HEAT TRANSFER AND FRICTION IN THE PLATE HEATING SURFACES OF THE KMS-2 AIR HEATER WITH A PRESSURE GRADIENT

2021 ◽  
Vol 11 (2) ◽  
pp. 23-29
Author(s):  
Nadezhda P. PETROVA ◽  
Anna A. TSYNAEVA ◽  
Valeriya V. BELAYA
Keyword(s):  
Heat Transfer ◽  
Pressure Gradient ◽  
Numerical Study ◽  
Initial Section ◽  
Variable Cross Section ◽  
Variable Pressure ◽  
Variable Cross ◽  
Average Value ◽  
Effi Ciency ◽  
Plate Heating

A numerical study of heat transfer and friction in the heat exchanger channels in the presence of a variable pressure gradient is performed. The research was carried out in software complexes (Code_Saturne, Salome). The results of the validation of the research method are presented and they showed that the deviation of the numerical simulation results from the calculation data according to the known criterion equations is within the error of generalization of the experimental data by the criterion equations. According to the results of studies at Red=3000, Red=4177, Red=6000, it was found that the average value of the heat transfer coeffi cient of the channel of variable cross-section is up to 20 % higher than for the channel at dp/dx0. At the same time, the thermal-hydraulic effi ciency of the alternating channel (L=117 mm, l=58.5 mm, n=2) in the initial section at x =0...0.08 is lower than in the channel with dp/dx>0 by 26.7 %, and at x =0.08...1 it is higher by 5 ... 15 %, at dp/dx

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

2011 ◽  
Vol 243-249 ◽  
pp. 4935-4938
Author(s):  
Li Li ◽  
Xiao Ze Du
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Cross Section ◽  
Heat Transfer Characteristic ◽  
Numerical Study ◽  
Transfer Characteristic ◽  
Variable Cross Section ◽  
Central Line ◽  
Large Reynolds Number ◽  
Variable Cross

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.

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.

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 ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Numerical Study ◽  
Narrow Channel ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Differential Model ◽  
Flow And Heat Transfer ◽  
Permeable Walls ◽  
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 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.

Boundary element method in numerical study of three-dimensional Stokes flows in channels of arbitrary shape

2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Cross Section ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cylindrical Tube ◽  
Variable Cross Section ◽  
Variable Cross ◽  
Periodic Flows ◽  
Element Method

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.

Investigation of heat transfer in a geometry with variable cross section

2009 ◽  
pp. n/a-n/a
Author(s):  
M. Alipanah ◽  
D.D. Ganji ◽  
E. Farnad ◽  
K. Babaei
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Variable Cross Section ◽  
Variable Cross

scholarly journals Oscillatory flow of a Casson fluid in an elastic tube with variable cross section

2018 ◽  
Vol 3 (2) ◽  
pp. 571-582 ◽  
Author(s):  
C.K. Selvi ◽  
A.N.S. Srinivas
Keyword(s):  
Pressure Gradient ◽  
Pressure Distribution ◽  
Cross Section ◽  
Oscillatory Flow ◽  
Axial Direction ◽  
Variable Cross Section ◽  
Casson Fluid ◽  
Elastic Parameter ◽  
Elastic Tube ◽  
Variable Cross

AbstractThe aim of this paper was to study an oscillatory flow of a Casson fluid through an elastic tube of variable cross section. The radial displacement of tube wall is taken into consideration. The problem is modelled under the assumption that the variation of the cross section of the tube is slow in the axial direction. Cylindrical coordinate system is chosen to study the problem. The analytical expressions for axial velocity and mass flux as a function of pressure gradient are obtained. The change in pressure distribution for various pressure****radius relationships is analyzed by considering different geometries. The effects of elastic parameter, Womersley parameter and Casson parameter on excess pressure and pressure gradient along axial direction are discussed through graphs. The results reveal that the elastic parameter plays a key role in the variation of pressure along the tube. Womersley parameter has significant effect on pressure distribution. Another important observation is that the amplitude of pressure increases for growing values of Casson parameter for both tapered and constricted tubes. In addition, the pressure oscillates more for the case of locally constricted tube when compared to other geometries.

scholarly journals Peristaltic Transport of Power-Law Fluid in an Elastic Tapered Tube with Variable Cross-Section Induced by Dilating Peristaltic Wave

2021 ◽  
pp. 1293-1306
Author(s):  
Mohammed Ali Murad ◽  
Ahmed M. Abdulhadi
Keyword(s):  
Pressure Gradient ◽  
Cross Section ◽  
Power Law ◽  
Variable Cross Section ◽  
Peristaltic Transport ◽  
Peristaltic Wave ◽  
Variable Cross ◽  
Power Law Fluid ◽  
Opposite Behavior ◽  
Local Shear

The peristaltic transport of power-law fluid in an elastic tapered tube with variable cross-section induced by dilating peristaltic wave is studied. The exact solution of the expression for axial velocity, radial velocity, stream function, local shear stress, volume of flow rate and pressure gradient are obtained under the assumption of long wavelength and low Reynolds number. The effects of all parameters that appear in the problem are analyzed through graphs. The results showed that the flux is sinusoidal in nature and it is an increasing function with the increase of  whereas it is a decreasing function with the increase of . An opposite behavior for shear strain is noticed compared to pressure gradient.  Finally, trapping phenomenon is presented to explain the physical behavior of various parameters. It is noted that the size of the trapping bolus increases with increasing  whereas it decreases as  increases. MATHEMATICA software is used to plot all figures.

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