scholarly journals Group Invariant Solutions for Flow and Heat Transfer of Power-Law Nanofluid in a Porous Medium

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Saba Javaid ◽  
Asim Aziz
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Power Law ◽  
Internal Heat ◽  
Shear Thickening ◽  
Internal Heat Source ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Flow And Heat Transfer ◽  
Power Law Nanofluid

The present work covers the flow and heat transfer model for the power-law nanofluid in the presence of a porous medium over the penetrable plate. The flow is caused by the impulsive movement of the plate embedded in Darcy’s type porous medium. The flow and heat transfer model has been examined with the effect of linear thermal radiation and the internal heat source or sink in the flow regime. The Rosseland approximation is utilized for the optically thick nanofluid. To form the closed-form solutions for the governing partial differential equations of conservation of mass, momentum, and energy, the Lie symmetry analysis is used to get the reductions of governing equations and to find the group invariants. These invariants are then utilized to obtain the exact solution for all three cases, i.e., shear thinning fluid, Newtonian fluid, and shear thickening fluid. In the end, all solutions are plotted for the cu -water nanofluid and discussed briefly for the different emerging flow and heat transfer parameters.

scholarly journals Group theoretical analysis for unsteady magnetohydrodynamics flow and radiative heat transfer of power-law nanofluid subject to Navier’s slip conditions

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258107
Author(s):  
Saba Javaid ◽  
Asim Aziz ◽  
Taha Aziz
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Power Law ◽  
Shear Thickening ◽  
Transfer Model ◽  
Closed Form Solutions ◽  
Flow And Heat Transfer ◽  
All Solutions ◽  
Navier’S Slip ◽  
Power Law Nanofluid

The present work covers the flow and heat transfer model for the Power-law nanofluid in the presence of a porous medium over a penetrable plate. The flow is caused by the impulsive movement of the plate embedded in Darcy’s porous medium. The flow and heat transfer models are examined with the effect of linear thermal radiation in the flow regime. The Rosseland approximation is utilized for the optically thick nanofluid. The governing partial differential equations are solved using Lie symmetry analysis to find the reductions and invariants for the closed-form solutions. These invariants are then utilized to obtain the exact solutions for the shear-thinning, Newtonian, and shear-thickening nanofluids. In the end, all solutions are plotted for the Cu-water nanofluid to observe the effect of different emerging flow and heat transfer parameters.

Correcting Turbocharger Performance Measurements for Heat Transfer and Friction

2017 ◽  
Author(s):  
Mario Schinnerl ◽  
Jan Ehrhard ◽  
Mathias Bogner ◽  
Joerg Seume
Keyword(s):  
Heat Transfer ◽  
Combustion Engine ◽  
Measurement Data ◽  
Internal Heat ◽  
Friction Model ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Friction Power ◽  
Turbine Efficiency ◽  
Compressor Efficiency

The measured performance maps of turbochargers which are commonly used for the matching process with a combustion engine are influenced by heat transfer and friction phenomena. Internal heat transfer from the hot turbine side to the colder compressor side leads to an apparently lower compressor efficiency at low to mid speeds and is not comparable to the compressor efficiency measured under adiabatic conditions. The product of the isentropic turbine efficiency and the mechanical efficiency is typically applied to characterize the turbine efficiency and results from the power balance of the turbocharger. This so-called ‘thermo-mechanical’ turbine efficiency is strongly correlated with the compressor efficiency obtained from measured data. Based on a previously developed one-dimensional heat transfer model, non-dimensional analysis was carried out and a generally valid heat transfer model for the compressor side of different turbochargers was developed. From measurements and ramp-up simulations of turbocharger friction power, an analytical friction power model was developed to correct the thermo-mechanical turbine efficiency from friction impact. The developed heat transfer and friction model demonstrates the capability to properly predict the adiabatic (aerodynamic) compressor and turbine performance from measurement data obtained at a steady-flow hot gas test bench.

Correcting Turbocharger Performance Measurements for Heat Transfer and Friction

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Mario Schinnerl ◽  
Jan Ehrhard ◽  
Mathias Bogner ◽  
Joerg Seume
Keyword(s):  
Heat Transfer ◽  
Combustion Engine ◽  
Measurement Data ◽  
Internal Heat ◽  
Friction Model ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Friction Power ◽  
Turbine Efficiency ◽  
Compressor Efficiency

The measured performance maps of turbochargers (TCs), which are commonly used for the matching process with a combustion engine, are influenced by heat transfer and friction phenomena. Internal heat transfer from the hot turbine side to the colder compressor side leads to an apparently lower compressor efficiency at low to midspeeds and is not comparable to the compressor efficiency measured under adiabatic conditions. The product of the isentropic turbine efficiency and the mechanical efficiency is typically applied to characterize the turbine efficiency and results from the power balance of the turbocharger. This so-called thermomechanical turbine efficiency is strongly correlated with the compressor efficiency obtained from measured data. Based on a previously developed one-dimensional (1D) heat transfer model, nondimensional analysis was carried out and a generally valid heat transfer model for the compressor side of different TCs was developed. From measurements and ramp-up simulations of turbocharger friction power, an analytical friction power model was developed to correct the thermomechanical turbine efficiency from friction impact. The developed heat transfer and friction model demonstrates the capability to properly predict the adiabatic (aerodynamic) compressor and turbine performance from measurement data obtained at a steady-flow hot gas test bench.

Sign in / Sign up

Export Citation Format

Share Document