scholarly journals Non fourier heat transfer enhancement in power law fluid with mono and hybrid nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Adil Sadiq

AbstractSeveral polymers like ethylene glycol exhibit non-Newtonian rheological behavior. Ethylene glycol is a world-widely used engine coolant and therefore, investigation of thermal enhancement by dispersing mono and hybrid nanoparticles in ethylene glycol is worthful. Since ethylene glycol has shear rate-dependent viscosity and it obeys the power-law rheological model. Therefore, based on these facts, the power-law rheological model with thermophysical properties is augmented with basic law of heat transfer in fluid for the modeling of the considered physical situation. $$Mo{S}_{2}$$ M o S 2 are taken as mono-nanoparticles where $$Mo{S}_{2}$$ M o S 2 and $$Si{O}_{2}$$ S i O 2 are taken as hybrid nanoparticles. Comparative study for the enhancement of thermal performance of MoS2 ethylene glycol and $$Mo{S}_{2}$$ M o S 2 −$$Si{O}_{2}$$ S i O 2 – ethylene glycol is done. For energy conservation, non-Fourier’s law of Cattaneo–Christov is used. The power-law fluid becomes more heat generative due to the dispersion of $$Mo{S}_{2}$$ M o S 2 and $$Si{O}_{2}$$ S i O 2 . However, $$Mo{S}_{2}$$ M o S 2 −power-law fluid is less heat generative relative to $$Mo{S}_{2}$$ M o S 2 − $$Si{O}_{2}$$ S i O 2 -nanofluid. Thermal relaxation time is found proportional to the ability of the fluid to restore its thermal equilibrium.

2021 ◽  
Author(s):  
M. Adil Sadiq

Abstract Several polymers like ethylene glycol exhibit non-Newtonian rheological behaviors. Ethylene glycol is a world-widely used engine coolant and therefore, investigation of thermal enhancement by dispersing mono and hybrid nanoparticles in ethylene glycol is worthful. Since, ethylene glycol has shear rate-dependent viscosity and it obeys the power law rheological model. Therefore, based on these facts, the power-law rheological model is used with thermophysical properties are augmented with basic laws of heat transfer in fluid for the modeling of considered physical situations. M oS 2 are taken as mono-nanoparticles where M oS 2 and SiO 2 are taken as hybrid nano-sized particles. Comparative study for the enhancement of thermal performance of M oS 2 ethylene glycol and M oS 2 −SiO 2 − ethylene glycol is done. For energy conservation, non-Fourier’s law of Cattaneo-Christov is used. Power law fluid becomes more heat generative due to dispersion of M oS 2 and SiO 2. However, M oS 2 −power law fluid is less heat generative relative to M oS 2 − SiO 2-nanofluid. Thermal relaxation time is found proportional to the ability of the fluid to restore its thermal equilibrium.


2012 ◽  
Vol 171-172 ◽  
pp. 67-82 ◽  
Author(s):  
Amir Nejat ◽  
Ehsan Mirzakhalili ◽  
Abbas Aliakbari ◽  
Mohammad S. Fallah Niasar ◽  
Koohyar Vahidkhah

Author(s):  
Anwar Ilmar RAMADHAN ◽  
Wan Hamzah AZMI ◽  
Rizalman MAMAT

In recent years, research has focused on enhancing the thermo-physical properties of a single component nanofluid. Therefore, hybrid or composite nanofluids have been developed to improve heat transfer performance. The thermo-physical properties of the Al2O3-TiO2-SiO2 nanoparticles suspended in a base of water (W) and ethylene glycol (EG) at constant volume ratio of 60:40 and different volume concentrations were investigated. The experiment was conducted for the volume concentrations of 0.05, 0.1, 0.2, and 0.3% of Al2O3-TiO2-SiO2 nanofluids at different temperatures of 30, 40, 50, 60, and 70 °C. Thermal conductivity and dynamic viscosity measurements were carried out at temperatures ranging from 30 to 70 °C by using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV III Ultra Rheometer, respectively. The highest thermal conductivity for tri-hybrid nanofluids was obtained at 0.3% volume concentration, and the maximum enhancement was increased up to 9% higher than the base fluid (EG/W). Tri-hybrid nanofluids with a volume concentration of 0.05% gave the lowest effective thermal conductivity of 4.8 % at 70 °C temperature. Meanwhile, the dynamic viscosity of the tri-hybrid nanofluids was influenced by volume concentration and temperature. Furthermore, tri-hybrid nanofluids behaved as a Newtonian fluid for volume concentrations from 0.05 to 3.0%. The properties enhancement ratio (PER) estimated that the tri-hybrid nanofluids will aid in heat transfer for all samples in the present. The new correlations for thermal conductivity and dynamic viscosity of tri-hybrid nanofluids were developed with minimum deviation. As a conclusion, the combination of the enhancement in thermal conductivity and dynamic viscosity for tri-hybrid at 0.3% volume concentration was found the optimum condition with more advantage for heat transfer than other concentrations.


1995 ◽  
Vol 17 (2) ◽  
pp. 34-39
Author(s):  
Nguyen Van Que

A numerical solution has been presented for free convection flow of power law fluid in a vertical cylinder of finite height. The average velocity along the channel and the heat transfer have been calculated. Graphs of velocities and temperature are shown. The results show good agreement with analytic one in the asymptotic case.


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