scholarly journals Augmentation of Nanofluids Heat Transfer in a Circular Pipe with Coiled Tube Insert as Heat Source and Swirl Generator

2019 ◽  
Vol 7 (4.14) ◽  
pp. 365
Author(s):  
S. D. Salman ◽  
. .
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flow Characteristics ◽  
Vortex Generator ◽  
Ansys Fluent ◽  
Coiled Tube ◽  
Swirl Generator ◽  
Momentum And Heat Transfer ◽  
Fluid Flow Characteristics ◽  
Steady State Heat Transfer

This research present steady state heat transfer and fluid flow characteristics in concentric pipe with coiled tube insert for turbulent flow regime with metal oxide nanofluid using ANSYS-FLUENT 18.0 where the governing equations of mass, momentum and heat transfer were solved simultaneously, using the k-e two equations turbulence model. Copper was chosen as the as metal for the construction of pipe and the helical tube insert. Coiled tube with curvature to pitch ratio as 1 and 2.5 mm in diameter with 1% volume fractions of TiO2 and CuO Nanofluid with Reynolds number ranged from 4000-16000 were considered in this research. The heat generated from constant water temperature (80 °C) with constant flow rates in helical coil (Re=4000). The Result shows that the heat and friction coefficients conducted by vortex generator raised with Reynolds number and accretion of nanoparticle presence. Furthermore, the maximum rate of heat transfer with significant intension in friction coefficient has been produced TiO2 nanofluid by as compared with CuO and water.  

scholarly journals Heat Transfer Characteristic on Wing Pairs Vortex Generator using 3D Simulation of Computational Fluid Dynamic

2021 ◽  
Vol 3 (2) ◽  
pp. 215-224
Author(s):  
Petrus Setyo Prabowo ◽  
◽  
Stefan Mardikus ◽  
Ewaldus Credo Eukharisto ◽  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Vortex Generator ◽  
Transfer Characteristic ◽  
Vortex Generators ◽  
Working Fluid ◽  
Longitudinal Vortices ◽  
Delta Winglet ◽  
Fluid Flow Characteristics

Vortex generators are addition surface that can increase heat transfer area and change the fluid flow characteristics of the working fluid to increase heat transfer coefficient. The use of vortex generators produces longitudinal vortices that can increase the heat transfer performance because of the low pressure behind vortex generators. This investigation used delta winglet vortex generator that was combined with rectangular vortex generator to Reynold numbers ranging 6,000 to 10,000. The parameters of Nusselt number, friction factor, velocity vector and temperature distribution will be evaluated.

scholarly journals Numerical Investigation of Heat Transfer and Fluid Flow Characteristics in a Rectangular Channel with Presence of Perforated Concave Rectangular Winglet Vortex Generators

2021 ◽  
Author(s):  
Syaiful ◽  
M. Kurnia Lutfi
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Rectangular Channel ◽  
Convection Heat Transfer ◽  
Flow Characteristics ◽  
Vortex Generator ◽  
Vortex Generators ◽  
Heated Plate ◽  
Convection Heat ◽  
Fluid Flow Characteristics

The high thermal resistance of the airside of the compact heat exchanger results in a low heat transfer rate. Vortex generator (VG) is one of the effective passive methods to increase convection heat transfer by generating longitudinal vortex (LV), which results in an increase in fluid mixing. Therefore, this study aims to analyze the convection heat transfer characteristics and the pressure drop of airflow in a rectangular channel in the presence of a concave rectangular winglet VG on a heated plate. Numerical calculations were performed on rectangular winglet pairs vortex generators (RWP VGs) and concave rectangular winglet pairs vortex generators (CRWP VGs) with a 45° angle of attack and one, two, and three pairs of VGs with and without holes. The simulation results show that the decrease in the value of convection heat transfer coefficient and pressure drop on CRWP with three perforated VG configuration is 4.63% and 3.28%, respectively, of the three pairs of CRWP VG without holes at an airflow velocity of 2 m/s.

Experimental and Numerical Investigations of Thermal Hydraulic Performance in Ribbed Channel for Combustor Liner

2019 ◽  
Author(s):  
Divya Bihari ◽  
Sanjay Bokade
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Enhancement ◽  
Pressure Loss ◽  
Rectangular Channel ◽  
Hydraulic Performance ◽  
Transfer Enhancement ◽  
Ansys Fluent ◽  
Transfer Measurement ◽  
Steady State Heat Transfer

Abstract The present study assess the thermal hydraulic performance of V-shaped, W-shaped and 2W-shaped ribs in a rectangular channel with an aspect ratio of 6:1. The rib-roughened copper plates were located at the bottom of the channel to simulate the backside wall cooling of gas turbine combustor liners. The rib height-to-hydraulic diameter ratio (e/Dh) was 0.05834 and the rib pitch-to-height ratio (P/e) was 10 for all the cases. The experiments were carried out at the Reynolds numbers ranging from 32000 to 72000. A steady state heat transfer measurement method is used to investigate the heat transfer enhancement of ribbed wall against a smooth wall. Pressure taps were located at two stream-wise locations in channel walls to measure the pressure loss. To validate the understanding of experimental data, all the rib configurations were investigated numerically using ANSYS FLUENT. A low Reynolds number k-ε turbulence model was used to predict the heat transfer in the channel. The results show that the 2W ribs have the highest heat transfer and pressure loss characteristics in channel. It gives around 1.4–1.6 times increase in average Nusselt number and 2.7–3.3 times increase in friction factor as compare to smooth plate. Among all the cases V ribs obtained lowest heat transfer and pressure loss characteristics. Furthermore, both heat transfer enhancement and pressure loss increases with increasing Reynolds number.

Numerical Determination of Heat Transfer and Pressure Drop Characteristics for a Converging–Diverging Flow Channel

1987 ◽  
Vol 109 (3) ◽  
pp. 606-612 ◽  
Author(s):  
M. Faghri ◽  
Y. Asako
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flow Characteristics ◽  
Flow Channel ◽  
Number Range ◽  
Minimum Height ◽  
Complex Fluid ◽  
Fluid Flow Characteristics ◽  
Maximum Minimum

A finite difference scheme was utilized to predict periodic fully developed heat transfer and fluid flow characteristics in a converging–diverging flow channel. The basis of the method is an algebraic nonorthogonal coordinate transformation which maps the complex fluid domain onto a rectangle. This transformation avoids the task of numerically generating boundary-fitted coordinates. The transformed equations and the entire discretization procedure were documented in an earlier paper which dealt with a general class of nonperiodic problems. Its adaptation to a periodic sample problem of converging–diverging flow channel will be illustrated in this work. Representative results were carried out for laminar flow, Prandtl number of 0.7, in the Reynolds number range from 90 to 1635, for various taper angles of converging–diverging flow channel, and for three ratios of maximum/minimum height of the flow channel. Moderate enhancement in the Nusselt number results occurred, at higher values of Reynolds number for most cases, when compared with corresponding values for straight ducts.

scholarly journals Effect of Dimpled Surface with Straight Spoiler Turbulators on Heat Transfer and Fluid Flow Characteristics for Channel

2019 ◽  
Vol 8 (12) ◽  
pp. 298-301 ◽  
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Transfer Rate ◽  
Flow Characteristics ◽  
Transfer Enhancement ◽  
Staggered Arrangement ◽  
Fluid Flow Characteristics ◽  
And Performance

An experimental investigation has been carried out for heat transfer enhancement over dimpled surface using spoiler turbulators. The experimentation is carried out over the aluminum plate of 1000 mm x 10 mm x 5 mm and Reynolds number ranging from 10,000 to 33,000. The δ/d ratio for dimple is 0.3, which is kept constant. The pitch for dimples are varied as 16 mm, 18 mm and 20 mm. Turbulators were used over the dimples surface in inline and staggered arrangement which provides different flow structure and produces turbulence. Turbulators are mounted over dimples at an angle of 12o with respect to flat plate. Experimental results were validated using Dittus-Boelter and Blasius equations. Analysis is made using Nusselt number, friction factor and performance index. It has been found that compared to dimpled plate performance of dimpled surface with spoiler tabulator plate is higher. If we compare inline and staggered arrangement, performance of inline arrangement dimple plate with turbulator is higher compared to staggered arrangement. This is due to in staggered arrangement at some locations chocking of flow may takes place which reduces heat transfer rate.

An Investigation of the Effect of interrupted fin arrangements on the Thermal Performance of a Heat Sink under a Free Convection Condition

2019 ◽  
Vol 7 (1) ◽  
pp. 43-53
Author(s):  
Abbas Jassem Jubear ◽  
Ali Hameed Abd
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Natural Convection ◽  
Thermal Performance ◽  
Heat Sink ◽  
Numerical Study ◽  
Ansys Fluent ◽  
Fluent Software ◽  
Steady State Heat ◽  
Steady State Heat Transfer

The heat sink with vertically rectangular interrupted fins was investigated numerically in a natural convection field, with steady-state heat transfer. A numerical study has been conducted using ANSYS Fluent software (R16.1) in order to develop a 3-D numerical model.  The dimensions of the fins are (305 mm length, 100 mm width, 17 mm height, and 9.5 mm space between fins. The number of fins used on the surface is eight. In this study, the heat input was used as follows: 20, 40, 60, 80, 100, and 120 watts. This study focused on interrupted rectangular fins with a different arrangement and angle of the fins. Results show that the addition of interruption in fins in various arrangements will improve the thermal performance of the heat sink, and through the results, a better interruption rate as an equation can be obtained.

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