UFR 4-18 Description: Difference between revisions
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Here some information about the objectives for investigating the flow in a pin-fin array and an overview about the works relevant to this flow are given. | |||
The present configuration has been studied in the framework of the 15th ERCOFTAC-SIG15/IAHR | |||
Workshop on Refined Turbulence Modelling which took place in 2011 at EDF Chatou, France (see | |||
http://wiki-projets.sp2mi.univ-poitiers.fr/bin/view/WorkshopChatou2011/Case15Dot2 for more details). | |||
This configuration has already been studied numerically | |||
by Delibra et al. [10], [11] using Unsteady Reynolds Average Navier Stokes (URANS) with the | |||
�-f model [10], [14] and hybrid Reynolds Average Navier Stokes/Large Eddy Simulation (hybrid | |||
RANS/LES) [11] for the two highest Reynolds numbers. They concluded that the URANS approach | |||
presented several discrepancies, among them, its inability to reproduce the unsteadiness of | |||
the flow around the first three arrays of the matrix. They also suggested that the small structures | |||
unresolved by URANS need to be predicted. This brought them to conduct hybrid RANS/LES | |||
(LES using a dynamic Smagorinsky model with RANS wall-treatment based on the �-f model | |||
[11]). They found that hybrid RANS/LES gave more acceptable accuracy than URANS in particular | |||
for capturing the large convective structures. Note that the computational domain of the | |||
URANS and hybrid RANS/LES approaches consisted of 8 by 2 and 8 by 1 pins, respectively, and that the wall temperature and not the heat flux was fixed. | |||
© copyright ERCOFTAC {{CURRENTYEAR}} | © copyright ERCOFTAC {{CURRENTYEAR}} | ||
Revision as of 21:17, 18 May 2015
Flow and heat transfer in a pin-fin array
Confined Flows
Underlying Flow Regime 4-18
Description
Introduction
Give a brief overview of the UFR in question. Describe the main characteristics of the type of flow. In particular, what are the underlying flow physics which characterise this UFR and must be captured by the CFD methods? If the UFR considered here is of special relevance for a particular AC featured in the KB, this should be mentioned.
It deals with 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 industrial configurations for internal cooling of gas-turbine blades and in the nuclear field. Experimental results from Ames et al. [2], [3], [4] have been made available for the Workshop
Review of UFR studies and choice of test case
Provide a brief review of past studies of this UFR which have included test case comparisons of experimental measurements with CFD results. Identify your chosen study (or studies) on which the document will focus. State the test-case underlying the study and briefly explain how well this represents the UFR? Give reasons for this choice (e.g a well constructed test case, a recognised international comparison exercise, accurate measurements, good quality control, a rich variety of turbulence or physical models assessed etc.) . If possible, the study should be taken from established data bases. Indicate whether of not the experiments have been designed for the purpose of CFD validation (desirable but not mandatory)?
Contributed by: Sofiane Benhamadouche — EDF
Here some information about the objectives for investigating the flow in a pin-fin array and an overview about the works relevant to this flow are given.
The present configuration has been studied in the framework of the 15th ERCOFTAC-SIG15/IAHR Workshop on Refined Turbulence Modelling which took place in 2011 at EDF Chatou, France (see http://wiki-projets.sp2mi.univ-poitiers.fr/bin/view/WorkshopChatou2011/Case15Dot2 for more details).
This configuration has already been studied numerically by Delibra et al. [10], [11] using Unsteady Reynolds Average Navier Stokes (URANS) with the �-f model [10], [14] and hybrid Reynolds Average Navier Stokes/Large Eddy Simulation (hybrid RANS/LES) [11] for the two highest Reynolds numbers. They concluded that the URANS approach presented several discrepancies, among them, its inability to reproduce the unsteadiness of the flow around the first three arrays of the matrix. They also suggested that the small structures unresolved by URANS need to be predicted. This brought them to conduct hybrid RANS/LES (LES using a dynamic Smagorinsky model with RANS wall-treatment based on the �-f model [11]). They found that hybrid RANS/LES gave more acceptable accuracy than URANS in particular for capturing the large convective structures. Note that the computational domain of the URANS and hybrid RANS/LES approaches consisted of 8 by 2 and 8 by 1 pins, respectively, and that the wall temperature and not the heat flux was fixed.
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