scholarly journals Experimental investigation of heat and mass transfer of an annular impinging jet

2021 ◽  
Vol 2039 (1) ◽  
pp. 012028
Author(s):  
M V Philippov ◽  
I A Chokhar ◽  
V V Terekhov ◽  
V I Terekhov ◽  
I N Baranov
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Experimental Study ◽  
Heat And Mass Transfer ◽  
Impinging Jet ◽  
Surface Cooling ◽  
Effective Surface ◽  
Flow And Heat Transfer ◽  
Annular Jet ◽  
Characteristic Features

Abstract This work presents an experimental study of a turbulent flow and heat transfer of an annular impinging jet for organizing effective surface cooling. Heat and mass transfer of the impinging annular jet was studied at Re = 5500. At that, a distance from the nozzle to the wall was varied. The focus was made on configurations with small nozzle-to-wall distances. It is shown that, depending on the indicated distance, fundamentally different flow regimes with characteristic features of heat transfer distribution are observed.

scholarly journals Similarities of Flow and Heat Transfer around a Circular Cylinder

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 658
Author(s):  
Hao Ma ◽  
Zhipeng Duan
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Circular Cylinder ◽  
Drag Coefficient ◽  
Heat And Mass Transfer ◽  
General Procedure ◽  
Fluid Flows ◽  
Flow And Heat Transfer ◽  
Transfer Behavior ◽  
Entire Flow

Modeling fluid flows is a general procedure to handle engineering problems. Here we present a systematic study of the flow and heat transfer around a circular cylinder by introducing a new representative appropriate drag coefficient concept. We demonstrate that the new modified drag coefficient may be a preferable dimensionless parameter to describe more appropriately the fluid flow physical behavior. A break in symmetry in the global structure of the entire flow field increases the difficulty of predicting heat and mass transfer behavior. A general simple drag model with high accuracy is further developed over the entire range of Reynolds numbers met in practice. In addition, we observe that there may exist an inherent relation between the drag and heat and mass transfer. A simple analogy model is established to predict heat transfer behavior from the cylinder drag data. This finding provides great insight into the underlying physical mechanism.

scholarly journals Heat and mass transfer enhancement strategies by impinging jets: A literature review

2020 ◽  
pp. 227-227
Author(s):  
Florin Bode ◽  
Claudiu Patrascu ◽  
Ilinca Nastase
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Large Scale ◽  
Impinging Jet ◽  
Impinging Jets ◽  
Nozzle Geometry ◽  
Small Scale ◽  
Mixing Enhancement ◽  
Transfer Enhancement

Heat and mass transfer can be greatly increased when using impinging jets, regardless the application. The reason behind this is the complex behavior of the impinging jet flow which is leading to the generation of a multitude of flow phenomena, like: large-scale structures, small scale turbulent mixing, large curvature involving strong normal stresses and strong shear, stagnation, separation and re-attachment of the wall boundary layers, increased heat transfer at the impinged plate. All these phenomena listed above have highly unsteady nature and even though a lot of scientific studies have approached this subject, the impinging jet is not fully understood due to the difficulties of carrying out detailed experimental and numerically investigations. Nevertheless, for heat transfer enhancement in impinging jet applications, both passive and active strategies are employed. The effect of nozzle geometry and the impinging surface macrostructure modification are some of the most prominent passive strategies. On the other side, the most used active strategies utilize acoustical and mechanical oscillations in the exit plane of the flow, which in certain situations favors mixing enhancement. This is favored by the intensification of some instabilities and by the onset of large scale vortices with important levels of energy.

Nanofluid Heat and Mass Transfer in a Deformable and Peristaltic Pump

2019 ◽  
Vol 8 (8) ◽  
pp. 1632-1639
Author(s):  
Aamir Ali ◽  
Y. Ali ◽  
D.N. Khan Marwat ◽  
M. Awais
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Surface Deformation ◽  
Wave Number ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Flow And Heat Transfer ◽  
Diffusion Parameters ◽  
Peristaltic Movement

Flow heat and mass transfer in a deformable channel of peristaltically moving walls is investigated in this paper. Moreover, the channel is filled with nanofluids. The purpose of this study is to examine the combined effects of surface deformation and peristaltic movement of the walls on the nanofluid flow in a channel. We have considered the effects of nanofluid in the peristaltically deformable porous channel whose walls are contracting or expanding in the normal direction. Nanofluids have been used to enhance the thermo-physical properties of fluids such as thermal diffusivity, thermal conductivity and convective heat transfer coefficients on flow and heat transfer. The analytic solution of the problem have been presented. We have analyzed the effects of different involved parameters such as Reynolds number, surface deformation parameter, Prandtl number, wave number, Brownian and thermophoretic diffusion parameters and Schmidt number on the velocity profile, the temperature profile, pressure distribution and the concentration profile with the help of graphs. The results are shown graphically and discussed physically. It is observed that the deformation increases the axial velocity and temperature of the fluid.

An Experimental Study on Heat and Mass Transfer in a Helical Absorber Using LiBr+LiI+LiNO3+LiCl Solution

2000 ◽  
Author(s):  
Jung-In Yoon ◽  
Choon-Geun Moon ◽  
Oh-Kyung Kwon ◽  
Eunpil Kim
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Experimental Study ◽  
Heat And Mass Transfer ◽  
Working Fluid ◽  
Transfer Performance ◽  
Falling Film ◽  
Absorption Chiller ◽  
Libr Solution ◽  
Cylindrical Form

Abstract An experimental study has been performed to investigate the heat and mass transfer performance in a falling film absorber of a domestic small-sized absorption chiller/heater. The components of the chiller/heater were concentrically arranged in a cylindrical form with low temperature generator, an absorber and an evaporator from the center. The arrangement of such a helical-type heat exchanger allows to make the system more compact as compared to a conventional one. As a working fluid, the LiBr+LiI+LiNO3+LiCl solution is used to get improved heat transfer. The heat and mass flux performance of the LiBr+LiI+LiNO3+LiCl solution shows 2 ∼ 5% increase than that of the LiBr solution. When a surfactant in the LiBr+LiI+LiNO3+LiCl solution is used, the performance of heat and mass transfer improves 15 ∼ 20%. This result shows the LiBr+LiI+LiNO3+LiCl solution with a surfactant can be applied to a small-sized absorption chiller/heater.

scholarly journals Analysis of Magnetohydrodynamics Flow of Incompressible Fluids over Oscillating Bottom Surface with Heat and Mass Transfer

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Vincent M. Bulinda ◽  
Giterere P. Kang’ethe ◽  
Phineas R. Kiogora
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Incompressible Fluids ◽  
Bottom Surface ◽  
Two Dimensional ◽  
Governing Equations ◽  
Flow And Heat Transfer ◽  
Explicit Finite Difference ◽  
Explicit Finite Difference Method

Analysis of magnetohydrodynamics flow of incompressible fluids over an oscillating bottom surface with heat and mass transfer is discussed. The flow is free convection in nature. Momentum, energy, and concentration equations are obtained for computation of their respective profiles. The unsteady flow two-dimensional governing equations are solved numerically by the explicit finite difference method of the Forward Time Backward Space scheme. The numerical results show that the applied parameters have significant effects on the fluid flow and heat transfer and have been discussed with the help of graphical illustrations.

Investigation of Flow and Heat Transfer Characteristics of Annular Impinging Jet

2014 ◽  
Vol 931-932 ◽  
pp. 1223-1227
Author(s):  
Watchara Musika ◽  
Makatar Wae-Hayee ◽  
Passakorn Vessakosol ◽  
Banyat Niyomwas ◽  
Chayut Nuntadusit
Keyword(s):  
Heat Transfer ◽  
Flow Behavior ◽  
Infrared Camera ◽  
Impinging Jet ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Annular Jet ◽  
Inner Diameter ◽  
Plate Distance

Flow and heat transfer characteristics of impinging jet from annular pipe were experimentally and numerically investigated. To generate annular jet, the cylindrical rod with 12.7 mm in diameter was inserted at center of pipe nozzle which has inner diameter (D) of 28.6 mm. The jet-to-plate distance (H) was examined in the range of 2D, 4D, 6D and 8D. The jet Reynolds number was fixed for all experiments at Re=20,000 based on averaged velocity and pipe inner diameter. The conventional jet was also studied for comparison. The temperature distribution on the impingement surface was measured using an infrared camera. The numerical simulation was carried out to visualize the flow behavior. The results show that the heat transfer of annular jet is higher than that the case of conventional pipe jet at low jet-to-plate distance (H=2D); however, the ones of annular and conventional jet are comparable when jet-to-plate distance becomes higher than H=6D.

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