The structural and Fluid flow analyses of the Hydrogen Absorber Window for the Muon Cooling collaboration project

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The structural and Fluid flow analyses of the
Hydrogen Absorber Window for the Muon Cooling
collaboration project
Presented at the MICE meeting at IIT 5 8 Feb
2002
By Wing Lau, Oxford University, UK
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• The FEA work reported herewith has two purposes-
• to look at the structural response of the Window
  undergoing a pressure increment to the burst
  pressure level
• and to understand the flow pattern of the fluid
  inside the Window compartment
• The pressure test 2 Window geometries have been
  analysed
• Window 1 -- with a thickness of 127?m at the
  centre of the crown
• Window 2 -- with a thickness of 330 ?m at the
  centre of the crown

Aim of the FEA analyses is to predict the
deflection of the Window under various pressure
load up to the first material UTS value at which
the burst of the Window is anticipated. It is
hope that the results, which were computed from
the non-linear FEA calculations, could be used to
compare with the photogrammetry results
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• The FE models include a 2-D axisymmetrical model
  on Windows 1 2, and a 3-D solid model for
  Window 2 only.
• The 2-D axisymmetrical model on Window 1 Window
  2 (same profile but slightly different crown
  thickness)
• The 3-D Solid model for Window 2

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Rate of the applied pressure in FEA
Stress-Strain relationship for the 6061-T6
material (actual stress-strain relationship may
vary slightly)
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The FEA results- Window 1 2D axisymmetrical
model The deflection of the Window under various
pressure
First yield at 0.14 MPa
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Window 1 2-D axisymmetrical model ( continue )
Deflection curve of particular points at the
crown area
Pressure at which first yield was detected
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Window 1 2-D axisymmetric model Establishing
the pressure at first yield. The centre of the
crown yielded at as early as 21 psi. It soon
spreaded to cover a patch of 2-3mm radius at
about 34 psi. UTS was detected at (centre of
crown ) about 47-48 psi
First yield at crown centre
General yield
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Window 1 2-D axisymmetrical model The animated
display of the Window deformation at various
internal pressure
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Comparison of results on Window 1at 0.18 Mpa test
pressure Comparing the Oxford FEA results with
the NIU photogrammetry and FEA results
FEA results by Oxford
Photogrammetry results FEA results by NIU
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Comparison of results on Window 1at 0.24 Mpa
test pressure Comparing the Oxford FEA results
with the NIU photogrammetry and FEA results
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Comparison of results on Window 1 Graph
summarizing the shape of the Window at the two
preceding pressures, and the final pressure
before it bursts.
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Window 2 - 2D axisymmetric model Window 2 has
the same basic profile of Window 1 except it is
nearly 3 times thicker at the centre of the crown
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Window 2 - 2D axisymmetric model
At 100 psi test pressure
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Window 2 - 2D axisymmetric model
At 109 psi test pressure (first UTS value)
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Window 2 - 2D axisymmetric model
Modified format ( linear curve added ) of the
photogrammetry results
First yield at approx. 79psi
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Animated stress development of the Window
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Window 2 3-D solid FEA model The animated
display of the Window deformation at various
internal pressure. They confirm that there is no
spurious harmonic variations around the Window.
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Comparison of results on Window 3 Graph
summarizing the shape of the Window at the
various pressures before it bursts.
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Window 3 2-D axisymmetrical model The animated
display of the Window deformation at various
internal pressure
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• Fluid Flow analysis to establish the
  relationship between the flow pattern, the inlet
  velocity, the fluid viscosity and the nozzle
  arrangements
• 2 models were set up
• A back to back Window arrangement with inlet and
  outlet nozzles perpendicular to the flange
  seating
• A back to back Window arrangement with inlet and
  outlet nozzles at an oblique angle to flange
  seating

Fluid boundary
Fluid
Plane of symmetry
inlet and outlet nozzles at an oblique angle to
flange seating
inlet and outlet nozzles perpendicular to the
flange seating
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• The Fluid model
• 2 different fluid medium were used for the run
• One using air at room temperature,
• and one using water ( to see the viscosity
  effect)
• For the air flow model, 2 inlet velocities were
  run on each model-
• At 5 m/s (relatively lamina flow)
• At 100 m/s ( turbulent flow )

Line of symmetry
Model 1 parallel nozzle arrangement
Model 2 oblique nozzle arrangement
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Results of the fluid flow analysis- Parallel
nozzle arrangement with air flow at room
temperature
Air inlet
Inlet velocity 5m/s Velocity profile in Y
direction
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Results of the fluid flow analysis- Parallel
nozzle arrangement with air flow at room
temperature
Air inlet
Inlet velocity 100 m/s Velocity profile in
Y-direction
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Results of the fluid flow analysis- Parallel
nozzle arrangement with air flow at room
temperature
Air inlet
Inlet velocity 5 m/s Vorticity profile
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Results of the fluid flow analysis- Oblique
nozzle arrangement with air flow at room
temperature
Air inlet
Inlet velocity 5 m/s Velocity profile in
Y-direction
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Results of the fluid flow analysis- Oblique
nozzle arrangement with air flow at room
temperature
Air inlet
Inlet velocity 100 m/s Velocity profile in
Y-direction
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Results of the fluid flow analysis- Oblique
nozzle arrangement with water flow at room
temperature
Water inlet
Water inlet velocity 5 m/s Velocity profile in
Y-direction
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Results of the fluid flow analysis- Oblique
nozzle arrangement with water flow at room
temperature
Water inlet
Water inlet velocity 5 m/s Velocity profile in
Z-direction
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Results of the fluid flow analysis- Oblique
nozzle arrangement with LH2 flow at room
temperature
LH2 inlet velocity 5 m/s Velocity profile in
Z-direction
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3-D Fluid Flow model A simple 3-D cylindrical
model with a parallel inlet and out nozzle was
set up to investigate the 3-D effect of the flow.
The flow medium is air at room temperature with
an inlet velocity of 100m/s. The 3-D model is-
Air out
Air in
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Preliminary results of the 3-D flow- A cut out
view showing half of the cylindrical section as
the outside boundary will have zero velocity
imposed throughout
Air in