Comparative Study of Cooling Performance of Automobile Radiator Using Al2O3-Water and Carbon Nanotube-Water Nanofluid

Author(s):  
Sandesh S. Chougule ◽  
S. K. Sahu

In the present study, the forced convective heat transfer performance of two different nanofluids, namely, Al2O3-water and CNT-water has been studied experimentally in an automobile radiator. Four different concentrations of nanofluid in the range of 0.15–1 vol. % were prepared by the additions nanoparticles into the water as base fluid. The coolant flow rate is varied in the range of 2 l/min–5 l/min. Nanocoolants exhibit enormous change in the heat transfer compared with the pure water. The heat transfer performance of CNT-water nanofluid was found to be better than Al2O3-water nanocoolant. Furthermore, the Nusselt number is found to increase with the increase in the nanoparticle concentration and nanofluid velocity.

2013 ◽  
Vol 465-466 ◽  
pp. 536-540
Author(s):  
Khairul Afif Fadzin ◽  
Ann Lee

Numerical investigation of heat transfer enhancement in two-dimensional microchannel heat sink (MCHS) using Al2O3-water, CuO-water and TiO2-water was conducted. The effect of different type of nanoparticles at particle volume concentration of 1%, 2% and 5% on the thermal performance in the MCHS was examined. The thermal performance is increased when nanofluids with high thermal conductivity and low dynamic viscosity was used. As the particle volume concentration increases, the heat transfer performance also improved. The result shows that the heat transfer performance of all the nanofluids used in this study was better than that of pure water. Overall, nanofluids with Al2O3-water at 5% particle volume concentration show the best cooling performance.


2019 ◽  
Vol 8 (4) ◽  
pp. 5892-5898

Nanofluids have good potential in enhancing the heat transfer performance of conventional fluids. In the present paper, the heat transfer performance of Fe3O4 and its Hybrid mixture with Fe3O4 and SiC nanoparticles in the volume ratio of 50:50 in 20:80 Ethylene Glycol (EG) –Water as base fluid are determined experimentally and the results are compared with that of the base fluid. The volume concentration range of nanoparticles considered in the analysis is 0.01% to 0.08%. The experiment is carried under turbulent flow conditions with Reynolds number ranging from 5000 to 20000 in a Double Pipe Heat Exchanger (DPHE) with U-bend. Results indicate that the thermal conductivity of hybrid nanofluid is higher by 16.19% and its viscosity is lower by 11.6% compared to Fe3O4 /20:80 EG-Water nanofluid at an operating temperature of 45°C. The heat transfer coefficient and overall performance of hybrid nanofluid are better than Fe3O4 /20:80 EG-Water nanofluid. The overall performance of Hybrid nanofluid is 27.75% better than that of Fe3O4 /20:80 EG-Water nanofluid.


2015 ◽  
Vol 787 ◽  
pp. 212-216 ◽  
Author(s):  
S. Senthilraja ◽  
K.C.K. Vijayakumar ◽  
R. Gangadevi

TIn this present study, the forced convection heat transfer performance of different fluids, namely, Al2O3-water, and CuO-water nanofluid has been studied experimentally in an automobile radiator. Three different concentration of nanofluid in the range of 0-1.0 vol.% have been prepared by addition of Al2O3and CuO nanoparticles into water. The test fluid flow rate can be varied in the range of 2 l/min to 5 l/min to have a fully turbulent regime. Obtained results demonstrate that the fluid circulating rate can improve the heat transfer performance. The heat transfer performance of CuO-water nanofluid was found better than the other heat transfer fluids. Furthermore, the Nusselt number is found to increase with the increase in the nanoparticle concentration and nanofluid velocity.


Author(s):  
Junfei Zhou ◽  
Xinjun Wang ◽  
Jun Li ◽  
Daren Zheng

A double swirl cooling method has been raised recently to enhance the internal cooling performance at the blade leading edge. This paper mainly focuses on investigating the flow and heat transfer characteristics of the double swirl cooling method. Further more, four kinds of elliptical holes are applied to show effects of impinging hole shapes on the cooling performance. Results of all double swirl cooling cases are compared with that of an impingement cooling structure under four Reynolds numbers. Overall averaged Nusselt number, friction factor and thermal performance factor are compared in all cases, Vortexes induced by different impinging hole types and target chambers are studied and compared. The spanwise averaged Nusselt number, Nusselt number contours and Nusselt number distributions at several cross sections are studied and compared. Results show that the double swirl cooling method can significantly enhance the heat transfer performance compared with the traditional impingement cooling structure. Double swirl cooling with cylindrical impinging hole shows the best thermal performance and lowest flow losses. By applying the elliptical impinging hole with the sharp side faced the mainstream flow direction and a larger major to minor axis length ratio, the rotational vortex inside the double swirl chamber can be better developed and the heat transfer performance is also promoted.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Naveen Janjanam ◽  
Rajesh Nimmagadda ◽  
Lazarus Godson Asirvatham ◽  
R. Harish ◽  
Somchai Wongwises

AbstractTwo-dimensional conjugate heat transfer performance of stepped lid-driven cavity was numerically investigated in the present study under forced and mixed convection in laminar regime. Pure water and Aluminium oxide (Al2O3)/water nanofluid with three different nanoparticle volume concentrations were considered. All the numerical simulations were performed in ANSYS FLUENT using homogeneous heat transfer model for Reynolds number, Re = 100 to 500 and Grashof number, Gr = 5000, 13,000 and 20,000. Effective thermal conductivity of the Al2O3/water nanofluid was evaluated by considering the Brownian motion of nanoparticles which results in 20.56% higher value for 3 vol.% Al2O3/water nanofluid in comparison with the lowest thermal conductivity value obtained in the present study. A solid region made up of silicon is present underneath the fluid region of the cavity in three geometrical configurations (forward step, backward step and no step) which results in conjugate heat transfer. For higher Re values (Re = 500), no much difference in the average Nusselt number (Nuavg) is observed between forced and mixed convection. Whereas, for Re = 100 and Gr = 20,000, Nuavg value of mixed convection is 24% higher than that of forced convection. Out of all the three configurations, at Re = 100, forward step with mixed convection results in higher heat transfer performance as the obtained interface temperature is lower than all other cases. Moreover, at Re = 500, 3 vol.% Al2O3/water nanofluid enhances the heat transfer performance by 23.63% in comparison with pure water for mixed convection with Gr = 20,000 in forward step.


2014 ◽  
Vol 22 (01) ◽  
pp. 1450005 ◽  
Author(s):  
SHUICHI TORII

This paper aims to study the convective heat transfer behavior of aqueous suspensions of nanoparticles flowing through a horizontal tube heated under constant heat flux condition. Consideration is given to the effects of particle concentration and Reynolds number on heat transfer enhancement and the possibility of nanofluids as the working fluid in various heat exchangers. It is found that (i) significant enhancement of heat transfer performance due to suspension of nanoparticles in the circular tube flow is observed in comparison with pure water as the working fluid, (ii) enhancement is intensified with an increase in the Reynolds number and the nanoparticles concentration, and (iii) substantial amplification of heat transfer performance is not attributed purely to the enhancement of thermal conductivity due to suspension of nanoparticles.


2014 ◽  
Vol 6 ◽  
pp. 147059 ◽  
Author(s):  
Behrouz Takabi ◽  
Saeed Salehi

This paper numerically examines laminar natural convection in a sinusoidal corrugated enclosure with a discrete heat source on the bottom wall, filled by pure water, Al2O3/water nanofluid, and Al2O3-Cu/water hybrid nanofluid which is a new advanced nanofluid with two kinds of nanoparticle materials. The effects of Rayleigh number (103≤Ra≤106) and water, nanofluid, and hybrid nanofluid (in volume concentration of 0% ≤ ϕ ≤ 2%) as the working fluid on temperature fields and heat transfer performance of the enclosure are investigated. The finite volume discretization method is employed to solve the set of governing equations. The results indicate that for all Rayleigh numbers been studied, employing hybrid nanofluid improves the heat transfer rate compared to nanofluid and water, which results in a better cooling performance of the enclosure and lower temperature of the heated surface. The rate of this enhancement is considerably more at higher values of Ra and volume concentrations. Furthermore, by applying the modeling results, two correlations are developed to estimate the average Nusselt number. The results reveal that the modeling data are in very good agreement with the predicted data. The maximum error for nanofluid and hybrid nanofluid was around 11% and 12%, respectively.


Author(s):  
Yan Wang ◽  
Xiang Ling

The heat transfer performance of fluid flowing in a microchannel was experimentally studied, to meet the requirement of extremely high heat flux removal of microelectronic devices. There were 10 parallel microchannels with rectangular cross-section in the stainless steel plate, which was covered by a glass plate to observe the fluid flowing behavior, and another heating plate made of aluminum alloy was positioned behind the microchannel. Single phase heat transfer and fluid flow downstream the microchannel experiments were conducted with both deionized water and ethanol. Besides experiments, numerical models were also set up to make a comparison with experimental results. It is found that the pressure drop increases rapidly with enlarging Reynolds number (200), especially for ethanol. With comparison, the flow resistance of pure water is smaller than ethanol. Results also show that the friction factor decreases with Reynolds number smaller than the critical value, while increases the velocity, the friction factor would like to keep little changed. We also find that the water friction factors obtained by CFD simulations in parallel microchannels are much larger than experiment results. With heat flux added to the fluid, the heat transfer performance can be enhanced with larger Re number and the temperature rise could be weaken. Compared against ethanol, water performed much better for heat removal. However, with intensive heat flux, both water and ethanol couldn’t meet the requirement and the temperature at outlet would increase remarkably, extremely for ethanol. These findings would be helpful for thermal management design and optimization.


2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Tingting Hao ◽  
Hongbin Ma ◽  
Xuehu Ma

A new oscillating heat pipe (OHP) charged with hybrid fluids can improve thermal performance. The key difference in this OHP is that it uses room temperature liquid metal (Galinstan consisting of gallium, indium, and tin) and water as the working fluid. The OHP was fabricated on a copper plate with six turns and a 3 × 3 mm2 cross section. The OHP with hybrid fluids as the working fluid was investigated through visual observation and thermal measurement. Liquid metal was successfully driven to flow through the OHP by the pressure difference between the evaporator and the condenser without external force. Experimental results show that while added liquid metal can increase the heat transport capability, liquid metal oscillation amplitude decreases as the filling ratio of liquid metal increases. Visualization of experimental results show that liquid metal oscillation position and velocity increase as the heat input increases. Oscillating motion of liquid metal in the OHP significantly increases the heat transfer performance at high heat input. The lowest thermal resistance of 0.076 °C/W was achieved in the hybrid fluids-filled OHP with a heat input of 420 W. We experimentally demonstrated a 13% higher heat transfer performance using liquid metal as the working fluid compared to an OHP charged with pure water.


2013 ◽  
Vol 805-806 ◽  
pp. 1817-1822 ◽  
Author(s):  
Zhang Jun Wang ◽  
Zhuo Xiong Zeng ◽  
Yi Hua Xu

Three-dimensional numerical study is performed for heat transfer and resistance characteristics as well as comprehensive performance of two kinds H-type (single and double) finned tube. It is found that the heat transfer and resistance characteristics as well as comprehensive performance of H-type finned tube are influenced by the Reynolds number of gas. With the growth of Reynolds number, the air-side Nusselt number rises gradually and the heat transfer performance gets better and better, whereas the air-side Euler number drops step by step until close to a fixed value. The comprehensive performances of both single H-type finned tube and double ones are weaken progressively. When Reynolds number value is same, the convective heat transfer, pressure drop, air-side Nusselt number and Euler number of single H-type finned tube are bigger than those of double ones. The single H-type finned tube expression is much better than double ones in comprehensive performance and heat transfer.


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