scholarly journals Heat transfer of power-law fluids under electrowetting actuation in structured microchannels

2022 ◽  
Vol 130 ◽  
pp. 105803
Author(s):  
Reza Izadi ◽  
Arshia Merdasi ◽  
Ali Moosavi
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Power Law Fluids

Forced convection heat transfer study of a blunt-headed cylinder in non-Newtonian power-law fluids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaspinder Kaur ◽  
Roderick Melnik ◽  
Anurag Kumar Tiwari
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Drag Coefficient ◽  
Power Law ◽  
Average Nusselt Number ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Total Drag ◽  
Shear Thinning Fluids ◽  
Power Law Fluids

Abstract In this present work, forced convection heat transfer from a heated blunt-headed cylinder in power-law fluids has been investigated numerically over the range of parameters, namely, Reynolds number (Re): 1–40, Prandtl number (Pr): 10–100 and power-law index (n): 0.3–1.8. The results are expressed in terms of local parameters, like streamline, isotherm, pressure coefficient, and local Nusselt number and global parameters, like wake length, drag coefficient, and average Nusselt number. The length of the recirculation zone on the rear side of the cylinder increases with the increasing value of Re and n. The effect of the total drag coefficient acting on the cylinder is seen to be higher at the low value of Re and its effect significant in shear-thinning fluids (n < 1). On the heat transfer aspect, the rate of heat transfer in fluids is increased by increasing the value of Re and Pr. The effect of heat transfer is enhanced in shear-thinning fluids up to ∼ 40% and it impedes it’s to ∼20% shear-thickening fluids. In the end, the numerical results of the total drag coefficient and average Nusselt number (in terms of J H −factor) have been correlated by simple expression to estimate the intermediate value for the new application.

Mixed Electroosmotic Pressure Driven Flow and Heat Transfer of Power Law Fluid in a Hydrophobic Microchannel

2017 ◽  
Author(s):  
Ainul Haque ◽  
Ameeya Kumar Nayak
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Joule Heating ◽  
Scientific Data ◽  
Channel Height ◽  
Flow And Heat Transfer ◽  
Power Law Fluids ◽  
Hydrophobic Microchannel ◽  
Pressure Driven Flow ◽  
Pressure Driven

In this paper, a mathematical model has been developed to analyze the combined electroosmotic and pressure driven flow of power law fluids in a micro channel in the presence of Joule heating effects. The effects of Navier slip boundary condition and thermal radiation is examined for effective heat transfer in a hydrophobic microchannel. The analytical treatment has been performed for fluid flow and heat transfer effects in terms of flow governing parameters. This study highlights the effect of channel height to the electric double layer thickness and observed the flow variation due to heat transfer effect with the available scientific data. For a pure EOF, velocity slip have more significant role to get a maximum flow rate as expected. For both pseudo-plastic and dilatent fluids Nusselt number is decreased with the increment of the hydrophobic parameter and dimensionless pressure gradient where as increment in Joule heating effect enhance the heat transfer rate.

Internal Heat Transfer to Power-Law Fluid Flows Through Porous Media

2000 ◽  
Author(s):  
B. K. Rao ◽  
J. P. McDevitt ◽  
D. L. Vetter
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Power Law ◽  
Polymer Concentration ◽  
Internal Heat ◽  
Fluid Flows ◽  
Vertical Tube ◽  
Uniform Heat Flux ◽  
Power Law Fluid ◽  
Power Law Fluids

Abstract Heat transfer and pressure drop were measured for flow of aqueous solutions of Carbopol 934 through a vertical tube filled with porous media. The heated stainless steel test section has an inside diameter of 2.25 cm, and is 200 diameters long. The porosity was varied from 0.32 to 0.68 by using uniform spherical glass beads. Uniform heat flux thermal boundary condition was imposed bypassing direct electric current through the tube wall. Over a range of the parameters: 45 &lt; Rea &lt; 7,000, 21 &lt; Pra &lt; 58, 0.62&lt;n (power-law exponent)&lt;0.80, 0.22 &lt; d/D &lt; 0.6, and the polymer concentration from 250 to 500 parts per million, the friction factor data for power-law fluids agreed with the Newtonian predictions. Heat transfer to power-law fluids increases with increasing Rea and Prw and decreasing porosity. A new correlation was proposed for predicting heat transfer to power-law fluid flows through confined porous media.

Numerical Simulation for Heat Transfer of Nanofluid in a Rotating Circular Groove Using a Continuous Finite Element Scheme

2014 ◽  
Vol 1081 ◽  
pp. 175-179 ◽  
Author(s):  
Yong Yue Jiang ◽  
Ping Lin ◽  
Bo Tong Li ◽  
Lin Li
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Power Law ◽  
Initial Time ◽  
The Finite Element Method ◽  
Finite Element Scheme ◽  
Element Scheme ◽  
Circular Groove ◽  
Power Law Fluids ◽  
Power Law Index

In this paper, we investigate the heat transfer of the power-law-fluids-based nanofluids in a rotating circular groove. The circular groove rotates with a constant speed and the temperature on the wall of the groove is different from the temperature inside in the initial time. The effects of thermophoresis and Brownian are considered. The thermal conductivity of the nanofluids is taken as a constant. We solve the model with the finite element method directly and discretize them using a continuous finite element scheme in space and a modified midpoint scheme in time. From the results we can find that the heat transfer enhancement of the nanofluids increases as the power law index of the base fluid decreases.

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