|
Abstract
|
Article Information:
Benchmarking the Performance of the ANSYS-FLUENT Standard k- ε Turbulence Model in Fluid Flow and Heat Transfer Predictions for Complex Flows around Circular Pin-Fins Using Various near Wall Functions
A. Al-Witry and M. Es-Saheb
Corresponding Author: A. Al-Witry
Submitted: July 31, 2012
Accepted: October 02, 2012
Published: May 01, 2013 |
Abstract:
|
This study compares CFD analyses of the fluid flow and heat transfer phenomena in a popular pin-fin geometry of X/D = 2.5, S/D = 2.5 and H/D = 1 for a range of Re = 5,000 to 30,000 to those from experiment to aid in the benchmarking the performance of the CFD code FLUENT. The CFD analyses use three ANSYS-FLUENT (version 13) near wall treatments available within the code: 1) the Standard Wall Function (SWF), 2) the Non-Equilibrium Wall Function (NEWF) and 3) the enhanced wall treatment. Experimental data used in this study were obtained from two papers: 1) by Chyu et al. (1998) for heat transfer predictions and another 2) by Metzgeret al. (1984) for pressure loss predictions, both for the same setup. The study also differentiates between the heat transfer occurring by the body of the pin-fin itself and that by the end-wall areas surrounding it. Results from the CFD analyses based on the fourth pin-fin from the inlet (commonly assumed to have a stable flow around it), show very good prediction accuracies of heat transfer coefficients for the pin-fin body itself but rather low accuracies for the end-wall areas (based on heat flux and inlet temperature values). Better accuracies were obtained when using the enhanced wall treatment where pin-fin body heat transfer coefficients were almost identical between the CFD and experimental results. An alternative definition of heat transfer based on the averaged local temperatures around the fourth pin-fin showed that the heat transfer coefficient then (with CFD's capability to establish the local thermal field) is really between 1.5 to 3.5 times that predicted by using the inlet temperature in deducing the local h values. The same accuracies cannot be said about its predictions of pressure loss coefficients where CFD results tended to be lower by 50-100%h.
Key words: CFD, FLUENT, forced convection, micro channels, pin-fins, turbulent flow, turbulence modeling, wall functions
|
|
Abstract
|
PDF
|
HTML |
|
Cite this Reference:
A. Al-Witry and M. Es-Saheb, . Benchmarking the Performance of the ANSYS-FLUENT Standard k- ε Turbulence Model in Fluid Flow and Heat Transfer Predictions for Complex Flows around Circular Pin-Fins Using Various near Wall Functions. Research Journal of Applied Sciences, Engineering and Technology, (17): 4301-4310.
|
|
|
|
 |
ISSN (Online): 2040-7467
ISSN (Print): 2040-7459 |
 |
| Information |
|
|
|
|
| Sales & Services |
|
|
|
|
