scholarly journals Network Electro-thermal Simulation of Non-isothermal Magnetohydrodynamic Heat Transfer from a Transpiring Cone with Buoyancy and Pressure Work

2016 ◽  
Vol 3 (2) ◽  
pp. 1525-1547 ◽  
Author(s):  
O. Anwar Bég ◽  
J. Zueco ◽  
Ali Kadir ◽  
Tasveer A. Bég ◽  
Umar F. Khan
Keyword(s):  
Heat Transfer ◽  
Thermal Simulation ◽  
Pressure Work

SPACE THERMAL SIMULATION FOR SATELLITE HEAT TRANSFER DESIGN EVALUATION

1974 ◽  
Author(s):  
Vasily D. Prian ◽  
Andy T. Calimbas ◽  
Edward A. LaBlanc
Keyword(s):  
Heat Transfer ◽  
Thermal Simulation ◽  
Design Evaluation

Modelling Conjugate Heat Transfer Within a Gas Turbine Secondary Air System Using 1D and 2-3D Solid Models in Thermo-Fluid System Simulation

2021 ◽  
Author(s):  
David Hunt ◽  
Youming Yuan ◽  
Ian Gardner
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Traditional Approach ◽  
Thermal Simulation ◽  
Solid Models ◽  
3D Elements ◽  
Secondary Air ◽  
3D Solid

Abstract This paper presents an implicit conjugate heat transfer (CHT) model designed for 1D systems of both solids and fluids. It demonstrates that this approach can be extended to include 2D and 3D elements being co-solved in a 2D or 3D thermal product. The approach is applied to a simple analytical problem and then to a Secondary Air Cavity within a Gas Turbine to illustrate the potential of this technique to be applied to more complex thermo-fluid simulations. Such simulations are important in trade off studies to balance minimizing engine bleed whilst ensuring sufficient cooling. The benefits of this CHT model are presented by comparison with the traditional approach of explicit co-simulation in which the temperature from the fluid domain is applied as a boundary condition to the thermal simulation and heat flux from the thermal simulation is applied as a boundary condition to the fluid domain (or vice versa). The ability to replace 1D elements with 2D or 3D elements allows model continuity from conceptual to detailed design and the reverse process potentially offers a route for model reduction later in lifecycle to support operation and maintenance through the use of an executable digital twin.

On the Pressure Dependency of Physical Parameters in Case of Heat Transfer Problems of Supercritical Water

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Gabor Hazi ◽  
Istvan Farkas
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Physical Parameters ◽  
Convective Term ◽  
Pressure Work ◽  
Thermophysical Parameters ◽  
Pressure Dependency ◽  
Order Of Magnitude ◽  
Transfer Problems ◽  
Work Done

Studying heat transfer problems of supercritical water, the pressure dependency of thermophysical parameters (density, specific heat, viscosity, and thermal conductivity) and the work done by pressure are often neglected. Here we show that the variations of some physical parameters as functions of pressure have the same order of magnitude than their variations as functions of temperature in supercritical water. Therefore, pressure dependency of physical parameters should be taken into account in heat transfer calculations of supercritical water. It is also pointed out that the work done by pressure should not be neglected in supercritical water since the pressure work term has the same order of magnitude than the convective term near the pseudocritical temperature.

The Effect of Viscous Dissipation on Two-Dimensional Microchannel Heat Transfer

2006 ◽  
Author(s):  
Jennifer van Rij ◽  
Tim Ameel ◽  
Todd Harman
Keyword(s):  
Heat Transfer ◽  
Viscous Dissipation ◽  
Slip Flow ◽  
Second Order ◽  
Slip Boundary Conditions ◽  
Pressure Work ◽  
Axial Conduction ◽  
Slip Boundary ◽  
Nusselt Numbers ◽  
Slip Flow Regime

Microchannel convective heat transfer characteristics in the slip flow regime are numerically evaluated for two-dimensional, steady state, laminar, constant wall heat flux and constant wall temperature flows. The effects of Knudsen number, accommodation coefficients, viscous dissipation, pressure work, second-order slip boundary conditions, axial conduction, and thermally/hydrodynamically developing flow are considered. The effects of these parameters on microchannel convective heat transfer are compared through the Nusselt number. Numerical values for the Nusselt number are obtained using a continuum based three-dimensional, unsteady, compressible computational fluid dynamics algorithm that has been modified with slip boundary conditions. Numerical results are verified using analytic solutions for thermally and hydrodynamically fully developed flows. The resulting analytical and numerical Nusselt numbers are given as a function of Knudsen number, the first- and second-order velocity slip and temperature jump coefficients, the Peclet number, and the Brinkman number. Excellent agreement between numerical and analytical data is demonstrated. Viscous dissipation, pressure work, second-order slip terms, and axial conduction are all shown to have significant effects on Nusselt numbers in the slip flow regime.

Pressure Work and Viscous Dissipation Effects on Heat Transfer in a Parallel–Plate Microchannel Gas Flow

2017 ◽  
Vol 35 (02) ◽  
pp. 243-254 ◽  
Author(s):  
K. M. Ramadan
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Viscous Dissipation ◽  
Convective Heat ◽  
Parallel Plate ◽  
Gas Flow ◽  
Combined Effect ◽  
Rarefaction Analysis ◽  
Pressure Work ◽  
Axial Conduction

ABSTRACTConvective heat transfer in a parallel plate microchannel gas flow is investigated analytically and numerically, considering the effects of viscous dissipation, pressure work, shear work, axial conduction and rarefaction. Analysis is performed with constant wall temperature and constant wall heat flux boundary conditions for both gas cooling and heating. The results presented demonstrate the significance of the combined effect of pressure work and viscous dissipation, shear work, rarefaction degree and axial conduction on microchannel convective heat transfer, in both the thermally developing and fully developed flow regions. Viscous dissipation and pressure work in a pressure-driven microchannel gas flow are of comparable magnitudes and may not be neglected from the energy equation. The shear work at the wall, which is effectively the combined effect of viscous dissipation and pressure work, needs to be included in the Nusselt number for better predictions of heat transfer.

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