Experimental study of the effect of solid volume fraction and Reynolds number on heat transfer coefficient and pressure drop of CuO–Water nanofluid

2016 ◽  
Vol 76 ◽  
pp. 342-351 ◽  
Author(s):  
Majid Zarringhalam ◽  
Arash Karimipour ◽  
Davood Toghraie
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Volume Fraction ◽  
Solid Volume Fraction

scholarly journals Toward improved heat dissipation of the turbulent regime over backward-facing step for the AL2O3-water nanofluids: An experimental approach

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1779-1789 ◽  
Author(s):  
Syed Ahmed ◽  
Salim Kazi ◽  
Ghulamullah Khan ◽  
Mohd Zubir ◽  
Mahidzal Dahari ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Turbulent Regime ◽  
Al2o3 Nanoparticles ◽  
Backward Facing Step ◽  
Constant Weight ◽  
Weight Concentration

Experimental study of nanofluid flow and heat transfer to fully developed turbulent forced convection flow in a uniformly heated tubular horizontal backward-facing step has reported in the present study. To study the forced convective heat transfer coefficient in the turbulent regime, an experimental study is performed at a different weight concentration of Al2O3 nanoparticles. The experiment had conducted for water and Al2O3 -water nanofluid for the concentration range of 0 to 0.1 wt.% and Reynolds number of 4000 to 16000. The average heat transfer coefficient ratio increases significantly as Reynolds number increasing, increased from 9.6% at Reynolds number of 4000 to 26.3% at Reynolds number of 16000 at the constant weight concentration of 0.1%. The Al2O3 water nanofluid exhibited excellent thermal performance in the tube with a backwardfacing step in comparison to distilled water. However, the pressure losses increased with the increase of the Reynolds number and/or the weight concentrations, but the enhancement rates were insignificant.

Experimental Study of Advanced Convective Cooling Techniques for Combustor Liners

2008 ◽  
Author(s):  
Michael Maurer ◽  
Uwe Ruedel ◽  
Michael Gritsch ◽  
Jens von Wolfersdorf
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Flow Field ◽  
Transfer Coefficient ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
Number Range ◽  
Convective Cooling

An experimental study was conducted to determine the heat transfer performance of advanced convective cooling techniques at the typical conditions found in a backside cooled combustion chamber. For these internal cooling channels, the Reynolds number is usually found to be above the Reynolds number range covered by available databases in the open literature. As possible candidates for an improved convective cooling configuration in terms of heat transfer augmentation and acceptable pressure drops, W-shaped and WW-shaped ribs were considered for channels with a rectangular cross section. Additionally, uniformly distributed hemispheres were investigated. Here, four different roughness spacings were studied to identify the influence on friction factors and the heat transfer enhancement. The ribs and the hemispheres were placed on one channel wall only. Pressure losses and heat transfer enhancement data for all test cases are reported. To resolve the heat transfer coefficient, a transient thermocromic liquid crystal technique was applied. Additionally, the area-averaged heat transfer coefficient on the W-shaped rib itself was observed using the so-called lumped-heat capacitance method. To gain insight into the flow field and to reveal the important flow field structures, numerical computations were conducted with the commercial code FLUENT™.

scholarly journals Experimental Study of HFE 7000 Refrigerant Condensation in Horizontal Pipe Minichannels

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6886
Author(s):  
Małgorzata Sikora ◽  
Tadeusz Bohdal ◽  
Karolina Formela
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Flux Density ◽  
Mass Flux ◽  
Internal Diameter ◽  
Two Phase ◽  
Horizontal Pipe

This article presents the results obtained from our own experimental investigations on heat exchange and pressure drop during the condensation flow of the HFE 7000 refrigerant in pipe minichannels with an internal diameter of di = 1.2–2.5 mm. The influence of vapor quality x and the mass flux density G on the two-phase flow pressure drops and heat transfer is presented. The tests were performed for the mass flux density range of G = 110–4700 kg/m2s, saturation inlet temperature of Ts = 36–43 °C and heat flux density of q = 1 ÷ 20 kW/m2. The pressure drop characteristics and heat transfer coefficient as a function of the internal diameter of minichannels are illustrated. The results of experimental research on the heat transfer coefficient and two-phase pressure drop are compared with correlations developed by other authors. The best accuracy has a comparison of experimental study with correlation of Rahman-Kariya-Miyara et al. and Mikielewicz et al.

scholarly journals Thermal-Hydraulic Performance of Graphene Nanoribbon and Silicon Carbide Nanoparticles in the Multi-Louvered Radiator for Cooling Diesel Engine

2020 ◽  
Vol 7 (1) ◽  
pp. F22-F29 ◽  
Author(s):  
E. Nogueira
Keyword(s):  
Heat Transfer ◽  
Silicon Carbide ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Analytical Solution ◽  
Transfer Coefficient ◽  
Mass Flow ◽  
Volume Fraction ◽  
Graphene Nanoribbon ◽  
The Heat Transfer Coefficient

Analytical solution for application and comparison of Graphene Nanoribbon and Silicon Carbide for thermal and hydraulic performance in flat tube Multi-Louvered Finned Radiator is presented. The base fluid is composed of pure water and ethylene glycol at a 50% volume fraction. The results were obtained for Nusselt number, convection heat transfer coefficient and pressure drop, for airflow in the radiator core and nanofluids in flat tubes. The main thermal and hydraulic parameters used are the Reynolds number, the mass flow rate, the Colburn Factor, and Friction Factor. In some situations, under analysis, the volume fraction, for Graphene Nanoribbon and Silicon Carbide, were varied. The value of the heat transfer coefficient obtained for Graphene Nanoribbon, for the volume fraction equal 0.05, is higher than twice the amount received by Silicon Carbide. The flow is laminar, for whatever the fraction value by volume of the Graphene nanoparticles when the mass flow of the nanofluid is relatively low. For turbulent flow and relatively small fractions of nanoparticles, the heat transfer coefficient is significantly high for mass flow rates of Graphene Nanoribbon. The pressure drop, for the same volume fraction of nanoparticles, is slightly higher than the pressure drop associated with Silicon Carbide. These high values for the heat transfer coefficient is a favorable result and of great practical importance, since lower values for the fraction in volume can reduce the costs of the compact heat exchanger (radiator). Keywords: analytical solution, nanofluid, compact exchanger, automotive radiator.

scholarly journals Numerical study of heat transfer in 90° bend tube by AI2O3 nano fluids using fluid injection

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hadi Mahdizadeh ◽  
Nor Mariah Adam
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Volume Fraction ◽  
Fluid Injection ◽  
Content Type ◽  
Nano Fluid ◽  
The Impact

Purpose This paper aims to investigate increasing heat transfer in bend tube 90° by fluid injection using nano fluid flow that was performed by expending varying Reynolds number. This paper studies the increased heat transfer in the bent tube that used some parameters to examine the effects of volume fraction, nanoparticle diameter, fluid injection, Reynolds number on heat transfer and flow in a bend pipe. Design/methodology/approach Designing curved tubes increases the thermal conductivity amount between fluid and wall. It is used the finite volume method and simple algorithms to solve the conservation equations of mass, momentum and energy. The results showed that the nanoparticles used in bent tube transfusion increase the heat transfer performance by increasing the volume fraction; it has a direct impact on enhancing the heat transfer coefficient. Findings Heat transfer coefficient enhanced 1.5% when volume fraction increased from 2 % to 6%, the. It is due to the impact of nanoparticles on the thermal conductivity of the fluid. The fluid is injected into the boundary layer flow due to jamming that enhances heat transfer. Curved lines used create a centrifugal force due to the bending and lack of development that increase the heat transfer. Originality/value This study has investigated the effect of injection of water into a 90° bend before and after the bend. Specific objectives are to analyze effect of injection on heat transfer of bend tube and pressure drop, evaluate best performance of mixing injection and bend in different positions and analyze effect of nano fluid volume fraction on injection.

Experimental study of the heat transfer coefficient and pressure drop of R1234yf condensing flow in flattened smooth tubes

2019 ◽  
Vol 106 ◽  
pp. 120-132 ◽  
Author(s):  
Hamidreza Fazelnia ◽  
Behrang Sajadi ◽  
Soorena Azarhazin ◽  
Mohammadali Akhavan Behabadi ◽  
Sajjad Zakeralhoseini
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Smooth Tubes ◽  
The Heat Transfer Coefficient

Boiling heat transfer coefficient and pressure drop of R1234yf flow inside smooth flattened tubes: An experimental study

2020 ◽  
Vol 165 ◽  
pp. 114595 ◽  
Author(s):  
Soorena Azarhazin ◽  
Behrang Sajadi ◽  
Hamidreza Fazelnia ◽  
Mohammad Ali Akhavan Behabadi ◽  
Sajjad Zakeralhoseini
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Boiling Heat Transfer ◽  
Boiling Heat Transfer Coefficient

Numerical Simulation of Ammonia Flow Boiling in a Horizontal Circular Tube

2013 ◽  
Vol 718-720 ◽  
pp. 162-165
Author(s):  
Sheng Long Wang ◽  
Yin Hai Ge ◽  
Wen Hao Li
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Volume Fraction ◽  
Cooling System ◽  
Flow Boiling ◽  
Convective Heat Transfer Coefficient ◽  
Air Cooling ◽  
Horizontal Pipe

In order to understand the variation of ammonia as a cooling refrigerant, the ammonia coolant is being used in power plant air cooling system. The subcooled boiling phase transformation of ammonia in a horizontal pipe tube was simulated through the application of the CFD fluid computational platform, the fluid state parameters in the tube were given at the same time. The speed variation along the axis of the tube was obtained, the speed is increasing, the Reynolds number corresponding substantial increase in the convective heat transfer coefficient corresponds to raise; The vapor volume fraction and boiling heat transfer coefficient along the tube were obtained. The boiling can strengthen the heat transfer significantly. The results showed that the ammonia as a cooling refrigerant by raising the Reynolds number and the use of the latent heat absorb these dual characteristics to improve the heat transfer coefficient is worth promoting.

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