Prof' Man Yeong Ha

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GFK 2003 Winter Workshop December 2th, 2003
A development of the high-performance and
high-efficiency heat exchanger design techniques
using LES/DNS/LBM under the Grid environment

• Prof. Man Yeong Ha
• School of Mechanical Engineering
• Pusan National University
• myha_at_pusan.ac.kr

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Contents

• Objective
• Activities
• Plan Result
• Scope
• Request

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Objective

• Development of the optimal heat exchanger design
  technique with high performance and high
  efficiency under the grid environment.
• Development of the parallel-computing program to
  solve the unsteady and 3-dimensional
  thermo-fluid flow in the heat exchanger
  under the grid environment.
• Development of the techniques to predict and
  minimize the aero-acoustic noise in the heat
  exchanger.
• Development of the optimal heat exchanger design
  techniques using the computer program with the
  optimization technique.

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Activities
(a) 3-dimensional unsteady thermal fluid flow
analysis using DNS/LES
- Complement of the parallelized code - To
complement and correct the code by analyzing the
result of it considering Grid environment.
- To apply immersed boundary method for complex
geometry of finned tube

• Detailed analyses for major objects
• 3-dimensional unsteady thermal fluid flow around
  finned tube
• The effect of shape of fin on flow Physical
  interpretation on how the complex turbulence
  structure affects the pressure drop and heat
  transfer coefficient of heat changer
• Methodology for optimal design Maximum heat
  transfer and minimum pressure drop.

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Activities
(b) Prediction of flow induced noise with
LBM(Lattice Boltzmann Method)
Literature survey on flow induced noise
Development of theoretical model
Development of LBM code for prediction of flow
induced noise
Acquisition of time dependent pressure
distribution
Parallelizing the LBM code and test
Development of noise-reducing technique with the
result of prediction code
Finding optimal design with minimized noise
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Activities
(c) International collaboration (USA, China)
Setting up of Grid environment for international
collaboration
Co-work with prof. Balachandar at dept. of TAM,
UIUC and NCSA for DNS/LES and Grid computing
Co-work with prof. Cens research group at
Zhejiang Univ. for multiphase flow and combustion
with LES and Grid computing
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Plan Result
Plan Result
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Scope

• Immersed Boundary Method
• Lattice Boltzmann Method
• Control of Cylinder wake in an aligned magnetic
  field
• International collaboration
• Make and setup a cluster for Grid testbed
• Performance test of CFD code

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Scope

• 1) Immersed Boundary Method

• Innovative approach to deal with the problem of
  modeling fluid flows interacting with a flexible,
  elastic boundary .

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Scope
- Cavity flow with elliptic body
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Scope
- Flows in a cavity with oscillating body
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Scope

• 2) Lattice Boltzmann Method

microscopic
macroscopic

• Fluid is treated as discrete groups of many
  particles repeating and translation collision.
• Macroscopic fluid dynamic is expressed by
  calculating two modes of particle motions.

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Scope
Coordinates
Polar coordinates
Number of the grid points
Computational domain
400times of circular cylinder
diameter d
Physical parameters
Reynolds number Re 150
Mach number M0.2
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Scope
- Generation of sound
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Scope
3) Control of Cylinder wake in an aligned
magnetic field

• Radial ( r ) direction
• Dirichlet conditions
• Buffer domain technique
• Definition of filter function
• Circumferential( ? ) direction
• Periodic condition

• Artificial perturbation
• Conveyor-belt type mechanism to initiate vortex
  shedding

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Scope

• Animations of vorticity and velocity vectors

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Scope

• Animations of temperature and pressure

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Scope
4) International collaboration
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Scope
6) Make and setup a cluster for Grid testbed
USER
EDDY server
WAKE server
VORTEX server
Gbit Ethernet
eddy1
wake1
vortex1
Fast Ethernet
wake2
vortex2
eddy2
wake3
vortex3
eddy3
wake4
vortex4
eddy4
eddy23
wake23
vortex23
wake24
eddy24
vortex24
24??
24??
24??
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Scope
6) Performance test of CFD code
Case 1 2

• 2D Cavity flow
• Unsteady
• Re 400
• No. of Gird 40,000

Streamlines
Temperature contours

• Case 1 Total Grid points fix
• Case 2 Grid points per node - fix

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Scope
Case 3

• Cylinder with circular fins
• DNS, 3D, Unsteady
• Re 300
• No. of Gird 700,000

Geometry
Vortical Structures
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Scope
Case 4

• Tubebanks
• LES, 3D, Unsteady
• Re 4,000
• No. of Gird 2,000,000

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Scope
Case 5

• Channel
• DNS LES, 3D, Unsteady
• Re 3,000
• No. of Gird 1,100,000

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Results
Case 1
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Results
Case 1
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Results
PNU KISTI
Case 1
Case 2
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Results
Case 3
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Results
Case 4
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Results
Case 5
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Results
Case 5
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Results
Case 5
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Results
Case 5
No. of nodes 14
No. of nodes 4
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Request

• Grid jobs are complicated and difficult.
• - It needs the monitoring toolkit and grid
  portal.
• 2) It needs testbed scattered over the country.
• - It needs a large number of testbed.
• 3) It needs stability of testbed.
• - It needs better system and strict
  administration.
• It needs discussion considering a method to
  acquire better efficiency of parallel job on the
  grid environment.
• It needs the collaboration among the researchers
  who investigate the application, grid
  middleware and network.

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Thank you