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=Flow and heat transfer in a pin-fin array=
 
=Flow and heat transfer in a pin-fin array=
 
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The test-case consists in the flow through a wall bounded pin matrix in a staggered arrangement with a heated bottom wall. In addition to its interest for the complex underlying physics, this case is close to several industrial configurations for internal cooling of gas-turbine blades, electronic devices and can be also found in the nuclear field.  
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The test-case consists of the flow through a wall bounded pin matrix in a staggered arrangement with a heated bottom wall. In addition to its interest for the complex underlying physics, this case is close to several industrial configurations found in internal cooling of gas-turbine blades, electronic devices and can be also found in the nuclear field.  
  
== Objectives ==
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Ames et al. (2004, 2005, 2006, 2007), carried out a fairly extensive experimental study for a particular configuration: the incompressible flow through a confined staggered pin fin array with a pitch to diameter ratio of 2.5, at three Reynolds numbers (3000, 10000, 30000) and with a heated bottom wall in the forced convection regime. Figures 1 to 3 show various instantaneous quantities in order to illustrate the complexity of the flow.
  
Ames et al. carried out a fairly extensive experimental study for a particular configuration: the incompressible flow through a confined staggered pin fin array with a pitch to diameter ratio of 2.5, at three Reynolds numbers (3000, 10000, 30000) and with a heated bottom wall in the forced convection regime (Ames et al. 2004, 2006, 2007 and 2008).
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This configuration has been chosen as a test case in the framework of the 15th ERCOFTAC-SIG15/IAHR Workshop on “Refined Turbulence Modelling” organized by the ERCOFTAC Special Interest Group on Turbulence Modelling (SIG15). This workshop took place at the EDF Lab Chatou (France) in 2011.  
  
and computationally by means of LES (Large Eddy Simulation) and URANS (Unsteady Reynolds Averaged Navier Stokes). Figures 1 to 3 show instantaneous variables in order to illustrate the complexity of the flow.
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Mainly EDF R&D has contributed to the benchmark exercise of the present test case through calculations with various models (LES and URANS). These calculations are presented herein and compared with the Ames et al. experimental results. Some observations from pre-workshop calculations of Delibra et al. (2008, 2009, 2010) are also included.
  
This configuration has been chosen as a test-case in the framework of the 15th ERCOFTAC-SIG15/IAHR Workshop on “Refined Turbulence Modelling” organized by the ERCOFTAC Special Interest Group on Turbulence Modelling (SIG15). This workshop took place at EDF Lab Chatou (France) in 2011.  
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Of primary interest in this case is the Nusselt number distribution on the bottom wall. However, pressure drop, mean-velocity components and turbulence quantities are also of interest and are compared to available experimental data.
  
results of the computational studies were analysed along with the experimental reference database
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Best practice guidelines are given for computing the considered test case with maximum confidence.
  
The challenging objective is to predict the right Nusselt number distribution on the the bottom wall.
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=== Acknowledgements ===
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The author would like to acknowledge F. Ames for providing the experimental results and W. Rodi for his thoughtful review.
  
Mainly EDF R&D has contributed calculations of the test case to the workshop with various models (LES,
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    URANS)
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-  These calculations presented here and compared with the Ames et al experimental results. Some observations from pre-workshop calculations of Delibra et al are also included.
 
-  of primary interest is Nusselt number distribution on bottom wall,  but mean-velocity, turbulence quantities and pressure drop  also of interest and presented and compared.
 
- best practice guidelines given for computing the test case considered with maximum confidence.
 
 
 
 
 
 
 
The primary objectives of the present contribution is twofold:
 
 
 
* to compare two kind of turbulence approaches (wall resolved LES and wall resolved URANS using two Linear Eddy Viscosity Models and one Reynolds Stress Model)
 
* give Best Practice Guidelines to compute the present test-case with a maximum confidence.
 
  
 
[[Image:Instantaneous Pressure.jpg]]<br/>
 
[[Image:Instantaneous Pressure.jpg]]<br/>
 
'''Figure 1:''' Intantaneous view of the pressure field on the pins and the bottom wall (LES, M76, Re=10000)
 
'''Figure 1:''' Intantaneous view of the pressure field on the pins and the bottom wall (LES, M76, Re=10000)
  
[[Image:Streamwise velocity.jpg]]<br/>
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[[Image:Streamwise velocity.jpg|vspace=100]]<br/>
 
'''Figure 2:''' Intantaneous view of the stream-wise velocity field (LES, M76, Re=10000)
 
'''Figure 2:''' Intantaneous view of the stream-wise velocity field (LES, M76, Re=10000)
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[[Image:Instantaneous Temperature Imposed HeatFlux.jpg]]<br/>
 
[[Image:Instantaneous Temperature Imposed HeatFlux.jpg]]<br/>
 
'''Figure 3:''' Intantaneous view of the temperature field (LES, M76, Re=10000, imposed heat flux)
 
'''Figure 3:''' Intantaneous view of the temperature field (LES, M76, Re=10000, imposed heat flux)
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Latest revision as of 11:03, 18 December 2015

Flow and heat transfer in a pin-fin array

Front Page

Description

Test Case Studies

Evaluation

Best Practice Advice

References

Confined Flows

Underlying Flow Regime 4-18

Abstract

The test-case consists of the flow through a wall bounded pin matrix in a staggered arrangement with a heated bottom wall. In addition to its interest for the complex underlying physics, this case is close to several industrial configurations found in internal cooling of gas-turbine blades, electronic devices and can be also found in the nuclear field.

Ames et al. (2004, 2005, 2006, 2007), carried out a fairly extensive experimental study for a particular configuration: the incompressible flow through a confined staggered pin fin array with a pitch to diameter ratio of 2.5, at three Reynolds numbers (3000, 10000, 30000) and with a heated bottom wall in the forced convection regime. Figures 1 to 3 show various instantaneous quantities in order to illustrate the complexity of the flow.

This configuration has been chosen as a test case in the framework of the 15th ERCOFTAC-SIG15/IAHR Workshop on “Refined Turbulence Modelling” organized by the ERCOFTAC Special Interest Group on Turbulence Modelling (SIG15). This workshop took place at the EDF Lab Chatou (France) in 2011.

Mainly EDF R&D has contributed to the benchmark exercise of the present test case through calculations with various models (LES and URANS). These calculations are presented herein and compared with the Ames et al. experimental results. Some observations from pre-workshop calculations of Delibra et al. (2008, 2009, 2010) are also included.

Of primary interest in this case is the Nusselt number distribution on the bottom wall. However, pressure drop, mean-velocity components and turbulence quantities are also of interest and are compared to available experimental data.

Best practice guidelines are given for computing the considered test case with maximum confidence.

Acknowledgements

The author would like to acknowledge F. Ames for providing the experimental results and W. Rodi for his thoughtful review.



Instantaneous Pressure.jpg
Figure 1: Intantaneous view of the pressure field on the pins and the bottom wall (LES, M76, Re=10000)





vspace=100
Figure 2: Intantaneous view of the stream-wise velocity field (LES, M76, Re=10000)





Instantaneous Temperature Imposed HeatFlux.jpg
Figure 3: Intantaneous view of the temperature field (LES, M76, Re=10000, imposed heat flux)





Contributed by: Sofiane Benhamadouche — EDF

Front Page

Description

Test Case Studies

Evaluation

Best Practice Advice

References


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