scholarly journals Heat Transfer and Fluid Flow Analysis for Turbulent Flow in Circular Pipe with Vortex Generator

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Kishor S. Rambhad ◽  
Vednath P. Kalbande ◽  
Manoj A. Kumbhalkar ◽  
Vivek W. Khond ◽  
Rahul A. Jibhakate
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Transfer Enhancement ◽  
Flow Analysis ◽  
Vortex Generator ◽  
Circular Pipe ◽  
List Type ◽  
Transfer Enhancement ◽  
Performance Of Heat Transfer ◽  
Fluid Flow Analysis

Abstract The performance of heat transfer enhancement (HTE) using modified inserts (MIs) as a vortex generator in pipe flow and fluid flow analysis using computational fluid dynamics (CFD) are evaluated in this article. The MIs are fastened to the central rod, and the circular sections of the MIs touched the circular wall of the test pipe. Heat transfer and fluid flow analyses are carried out for the various pitch to diameter ratios (P/D) and angles of the MIs. P/D ratios of 3, 4 and 6 and MIs angles of 15°, 30°, 45°, 60° and 90° are considered for experimental analysis. CFD analysis is carried out for P/D ratios of 3, 4 and 6 and MIs angles of 30°, 45° and 90°. Nusselt number (Nu/Nus) and friction factor (f/fs) ratios are evaluated using the same Reynolds number between 8000 and 17,000 in the experimental study. The MIs encourage the wall and core fluid to be combined thus helps in HTE. It is found that, as the P/D ratio increases, the Nu/Nus and f/fs decrease. If the distance between the MIs increases, the mixing of fluid weakens. With decreasing the P/D ratio, Nu/Nus increases. Increased fluid mixing leads to a higher coefficient of heat transfer and higher values of pressure drop. A P/D ratio of 4 and MIs angle of 45° results in greater heat interaction than others. Finally, recommendations for the best P/D ratio and angles of MIs are made for improved HTE on fluid flow through a circular pipe. Article Highlights Modified inserts (MIs) are used inside the test pipe to check the heat transfer enhancement at various angles. Also, compared the performance with and without MIs. Fluid flow analysis is checked by CFD (Fluent) in Ansys software. Fluid flow patterns for various MIs angles and P/D ratios are compared.

Flow and Heat Transfer Enhancement of Nanofluids in Microchannel With Blocks and Grooves

2013 ◽  
Author(s):  
Ping Li ◽  
Jianhui Chen ◽  
Huancheng Qu ◽  
Yonghui Xie ◽  
Di Zhang
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Heat Transfer Enhancement ◽  
Energy Transport ◽  
Recirculation Zone ◽  
Volume Concentration ◽  
Flow Analysis ◽  
Transfer Enhancement ◽  
Flow And Heat Transfer

A code based on the lattice-Boltzmann method was programmed. At various Reynolds numbers, simulations of the Cu/water nanofluid flow structure and heat transfer performance in a two dimensional microchannel with blocks (Re = 10–100) and grooves (Re = 50–200) were conducted, and the factors affecting the flow and heat transfer were explored. The flow and heat transfer of nanofluids with nanoparticle volume concentration of 0.5%, 1.0%, 1.5% and 2.0% were simulated, obtaining the velocity and temperature distributions to compare with the results of base fluid. Flow analysis showed that recirculation zones formed behind the blocks and in the grooves when nanofluids flowed in the microchannel, and the size of recirculation zone increased with the increase of Reynolds number and nanoparticle volume concentration. The core of the recirculation zone in the groove gradually moved to the right wall as Reynolds number increased at the same nanoparticle volume concentration, and the direction of the main flow was getting horizontal. Heat transfer results indicated that the addition of nanoparticles could promote fluid flow and energy transport, so that the thermal boundary layer thickness decreased and the heat transfer was enhanced. The heat transfer enhancement increased with the increase of Reynolds number and nanoparticle volume concentration. It was also shown that the heat transfer enhancement by increasing the Reynolds number was limited. The results could give a fundamental understanding for designing highly efficient heat exchangers.

scholarly journals Heat and Fluid Flow Analysis and ANN-Based Prediction of a Novel Spring Corrugated Tape

2021 ◽  
Vol 13 (6) ◽  
pp. 3023
Author(s):  
Basma Souayeh ◽  
Suvanjan Bhattacharyya ◽  
Najib Hdhiri ◽  
Mir Waqas Alam
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Transfer Enhancement ◽  
Energy Transport ◽  
Flow Analysis ◽  
Substantial Contribution ◽  
Working Fluid ◽  
Pumping Power ◽  
Transfer Enhancement ◽  
Depth Ratio

A circular tube fitted with novel corrugated spring tape inserts has been investigated. Air was used as the working fluid. A thorough literature review has been done and this geometry has not been studied previously, neither experimentally nor theoretically. A novel experimental investigation of this enhanced geometry can, therefore, be treated as a new substantial contribution in the open literature. Three different spring ratio and depth ratio has been used in this study. Increase in thermal energy transport coefficient is noticed with increase in depth ratio. Corrugated spring tape shows promising results towards heat transfer enhancement. This geometry performs significantly better (60% to 75% increase in heat duty at constant pumping power and 20% to 31% reduction in pumping power at constant heat duty) than simple spring tape. This paper also presented a statistical analysis of the heat transfer and fluid flow by developing an artificial neural network (ANN)-based machine learning (ML) model. The model is evaluated to have an accuracy of 98.00% on unknown test data. These models will help the researchers working in heat transfer enhancement-based experiments to understand and predict the output. As a result, the time and cost of the experiments will reduce. The results of this investigation can be used in designing heat exchangers.

scholarly journals Heat transfer and fluid flow analysis using nanofluids in diamond-shaped cavities with novel obstacles

2021 ◽  
Vol 15 (1) ◽  
pp. 1034-1056
Author(s):  
Alireza Aghaei ◽  
Suvanjan Bhattacharyya ◽  
Amin Dezfulizadeh ◽  
A.S. Goldanlou ◽  
S. Rostami ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Flow Analysis ◽  
Fluid Flow Analysis

Optimal Position of Rectangular Vortex Generator for Heat Transfer Enhancement in a Flat-Plate Channel

2017 ◽  
Author(s):  
Tariq Amin Khan ◽  
Wei Li ◽  
Zhengjiang Zhang ◽  
Jincai Du ◽  
Sadiq Amin Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Numerical Simulations ◽  
Flat Plate ◽  
Heat Transfer Enhancement ◽  
Angle Of Attack ◽  
Vortex Generator ◽  
Transfer Enhancement ◽  
Optimal Position ◽  
Plate Channel

Heat transfer is a naturally occurring phenomenon which can be greatly enhanced by introducing longitudinal vortex generators (VGs). As the longitudinal vortices can potentially enhance heat transfer with small pressure loss penalty, VGs are widely used to enhance the heat transfer of flat-plate type heat exchangers. However, there are few researches which deal with its thermal optimization. Three dimensional numerical simulations are performed to study the effect of angle of attack and attach angle (angle between VG and wall) of vortex generator on the fluid flow and heat transfer characteristics of a flat-plate channel. The flow is assumed as steady state, incompressible and laminar within the range of studied Reynolds numbers (Re = 380, 760, 1140). In the present work, the average and local Nusselt number and pressure drop are investigated for Rectangular vortex generator (RVG) with varying angle of attack and attach angle. The numerical results indicate that the heat transfer and pressure drop increases with increasing the angle of attack to a certain range and then decreases with increasing angle of attack. Moreover, the attach angle also plays an importance role; a 90° attach angle is not necessary for enhancing the heat transfer. Usually, heat transfer enhancement is achieved at the expense of pressure drop penalty. To find the optimal position of vortex generator to obtain maximum heat transfer and minimum pressure drop, the data obtained from numerical simulations are used to train a BRANN (Bayesian-regularized artificial neural network). This in turn is used to drive multi-objective genetic algorithm (MOGA) to find the optimal parameters of VGs in the form of Pareto front. The optimal values of these parameters are finally presented.

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