Experimental Investigation of Combined Effect of Particle Size and Stability of Al2O3-H2O Nanofluid on Heat Transfer Augmentation Through Horizontal Pipe

2020 ◽  
Vol 38 (4A) ◽  
pp. 561-573
Author(s):  
Abdulhassan ِA. Karamallah ◽  
ِHayder H. Abed
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Friction Factor ◽  
Constant Heat Flux ◽  
Engineering Systems ◽  
Horizontal Pipe ◽  
Heat Transfer Augmentation ◽  
Fully Developed Turbulent Flow ◽  
Effect Of Particle Size ◽  
The Stability

The stability of nanofluid plays a rule in heat transfer growth for different engineering systems. The stability and particle size of Al2O3-H2O nanofluid effects on heat transfer are studied experimentally. Two particle sizes (20 and 50 nm) with (0.1, 0.5 and 1%) concentrations were prepared and tested under constant heat flux (1404 W) with fully developed turbulent flow through a horizontal pipe. The results show an increase in Nusselt number by 20.7% and 17.6% with 1 vol.% concentration for 20 and 50 nm, respectively compared to distilled water. Examined nanofluid showed improvement in Nu number by (30.3 and 23.5) % at 1 vol.% concentration compared to water. Obtained results show minor decrease in the pressure drop and friction factor with nanofluid after stability treatment. Different correlations between Nu number and friction factor relating to studied parameters were observed.

scholarly journals Numerical Analysis for Heat Transfer Augmentation in a Circular Tube Heat Exchanger Using a Triangular Perforated Y-Shaped Insert

Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 247
Author(s):  
Lokesh Pandey ◽  
Satyendra Singh
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Circular Tube ◽  
Tube Wall ◽  
Constant Heat Flux ◽  
Working Fluid ◽  
Tube Heat Exchanger ◽  
Heat Transfer Augmentation ◽  
Plain Tube

The present investigation constitutes CFD analysis of the heat transmission phenomenon in a tube heat exchanger with a Y-shaped insert with triangular perforation. The analysis is accomplished by considering air as a working fluid with a Reynolds number ranging from 3000 to 21,000. The segment considered for analysis consists of a circular tube of 68 mm diameter and 1.5 m length. The geometrical parameter considered is the perforation index (0%, 10%, 20%, and 30%). The constant heat flux is provided at the tube wall and a pressure-based solver is used for the solution. The studies are performed for analyzing the effects of inserts on the heat transfer and friction factor in the circular tube heat exchanger which results in augmented heat transfer at a higher perforation index (PI) and lower friction factor. The investigation results show that the highest heat transfer is 5.84 times over a simple plain tube and the maximum thermal performance factor (TPF) is 3.25 at PI = 30%, Re = 3000.

Prediction of Heat Transfer in Turbulent Decaying Swirling Flow

1999 ◽  
Author(s):  
Yusuf A. Uskaner
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Experimental Study ◽  
Friction Factor ◽  
Loss Factor ◽  
Swirling Flow ◽  
Swirling Flows ◽  
Heat Transfer Augmentation ◽  
Relative Roughness ◽  
Inlet Swirl

Abstract This paper presents an aproach for the prediction of heat transfer augmentation in decaying swirling flow in a pipe by making an analogy between the increase in friction factor due to swirl and increase in heat transfer due to swirl. The proposed method can be used to predict heat transfer for decaying swirling flow in smooth and rough pipes which can be applied to different swirl generators based on the known inlet swirl conditions. An experimental study is performed regarding the swirling flow of air in smooth and rough pipes. The experimental study covered only the fluid dynamics of swirling flow. No heat transfer experiments were done. It is determined experimentally that in swirling flows degree of swirl decays continuously along the smooth and rough pipes and the total loss factor is the sum of friction factor for non-swirling flow and the swirl loss factor. Swirl loss factor is found to be a function of the degree of swirl and pipe relative roughness. Using the relations obtained experimentally for the variation of swirl strength and loss factor along the pipe, an equation is proposed to be used for the prediction of heat transfer in turbulent decaying swirling flows.

FORCED CONVECTION BASED HEAT TRANSFER ANALYSIS OF SPHERICAL DIMPLE AND PROTRUSION SURFACE IN TURBULENT FLOW

2017 ◽  
Vol 41 (5) ◽  
pp. 771-786 ◽  
Author(s):  
Ashif Perwez ◽  
Shreyak Shende ◽  
Rakesh Kumar
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Vortex Flow ◽  
Rectangular Channel ◽  
Heat Transfer Analysis ◽  
Flow Structures ◽  
Transfer Enhancement ◽  
Heat Transfer Augmentation ◽  
Thermal Boundary Conditions

An experimental and numerical investigation is performed to study the effect of dimple and protrusion geometry on the heat transfer enhancement and the friction factor of surfaces with dimples and protrusions subjected to turbulent flow. The parameters used to compare the spherical dimples and protrusions are Nusselt Number, friction factor, and flow pattern. These parameters are obtained for a Reynolds number of 10500-60900. The spherical dimple results showed the greater heat transfer, which is about 6.97% higher and pressure loss which is 5.07% lower than the spherical protrusion. The realistic heat transfer augmentation capabilities of channels with dimples and protrusions can be studied from the experimental results. The comparison is made with respect to the smooth rectangular channel under the same flow and thermal boundary conditions. The numerical analysis is performed which shows the different vortex flow structures of the spherical dimples and protrusions channel.

Heat Transfer in Turbulent Pipe Flow With Optically Thin Radiation

1969 ◽  
Vol 91 (3) ◽  
pp. 330-335 ◽  
Author(s):  
C. S. Landram ◽  
R. Greif ◽  
I. S. Habib
Keyword(s):  
Heat Transfer ◽  
Circular Tube ◽  
Constant Heat Flux ◽  
Turbulent Pipe Flow ◽  
Radiation Problem ◽  
Constant Heat ◽  
Nusselt Numbers ◽  
Fully Developed Turbulent Flow ◽  
Good Agreement

The problem considered is the determination of the heat transfer in fully developed turbulent flow of a radiating optically thin gas in a circular tube. The radiation problem is formulated in terms of the Planck mean and the modified Planck mean coefficients and the temperature profiles and Nusselt numbers have been determined. It is shown that the simple constant shear, constant heat flux formulation yields results that are in very good agreement with more complex calculations.

scholarly journals Heat transfer intensification of Zirconia/water nanofluid

2017 ◽  
Vol 13 ◽  
pp. 01-08
Author(s):  
Mohamed Iqbal Shajahan ◽  
Chockalingam Sundar Raj ◽  
Sambandan Arul ◽  
Palanisamy Rathnakumar
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Laminar Flow ◽  
Friction Factor ◽  
Volume Concentration ◽  
Constant Heat Flux ◽  
Particle Volume ◽  
Heat Transfer Intensification ◽  
Nusselt Numbers ◽  
Thermal Analyser

This paper investigated convective heat transfer and friction factor of ZrO2/H2O nanofluid through a circular pipe under laminar flow condition with constant heat flux. Nanofluid is prepared for 0.5, 0.75 and 1% volume concentrations with yttrium oxide surfactant. Nanofluid’s thermal conductivity and viscosity is measured by KD2 Pro thermal analyser and Brookfield viscometer respectively. Results showed that the thermal conductivity and viscosity increased with increase in particle volume concentration. These nanofluids are experimented in a forced convection system, first heat transfer characteristics of DI (Deionised) water  under laminar flow in a copper tube measured, then three nanofluids are carried out the tests, results revealed that the enhanced Nusselt numbers of 21.09,28.05 and 35.73%  at the 0.5, 0.75 and 1% volume concentrations, There is no excess penalty in pumping power  and results showed  less variations in friction factor for nanofluids comparatively with the base fluid DIWater.

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