ALTE DOCUMENTE
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Wall-driven flow between infinite parallel plates, separated by a distance H. Upper horizontal wall moves at constant velocity, Vwall, while lower horizontal wall is fixed. Left and right vertical boundaries are periodic.
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Fluid Properties |
Geometry |
Meshing |
Loading 737x233h |
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r |
Lx = 4 |
Nx = 4, 1 |
Vwall = 1 |
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m |
H =1 |
Ny = 10, -4 |
Steady-state
Incompressible
VY = VZ = 0
VX = VX(Y) only
Pressure field is constant
No body forces
Fluid properties are constant
Input File: Step51
Data: Armaly, et. al., "Experimental and Theoretical Investigation of Backward Facing Step Flow", Journal of Fluid Mechanics (1983), vol. 127, pp. 473-496.
Inlet length: 2.5 (can be varied by the user)
Outlet length: 18 (can be varied by the user)
Outlet Condition: P
= 0
use density = 1.0,
viscosity = .001
Hydraulic diameter
Dh = 2(.52) = 1.04
Choose Reynolds Number between 200 and 1000
Watch for the length of the recirculation region and secondary recirculation regions.
How much are results affected by the inlet velocity profile?
How can the choice of the outlet condition be verified?
Turbulent cross-flow over a bundle of circular tubes. Top and bottom horizontal boundaries are planes of symmetry.
Define all keypoints in terms of parameters.
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Use: |
R |
LIN | ||||
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DX |
LOUT | |||||
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DY |
Create an ALL-QUAD mesh (requires concatenations just before meshing). Concentrate nodes towards tube walls.
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Fluid Properties |
Meshing |
Loading 737x233h |
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r |
Check Line Directions |
VIN = 1 |
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m = 1.0E-4 |
Pout = 0 |
Steady-state
Incompressible
Turbulent
Fluid properties are constant
In this device, orifice plates are separated by spacer plates in a stack arrangement, with consecutive plates having an offset hole pattern. Multiple jets of coolant fluid impinge on conductive surfaces to maximize heat transfer. The plate stack is metalluragically bonded together to minimize conductive resistance. Flow is to be modeled in the quarter-symmetry section shown.
Construct flowfield using top-down techniques.
Generate the 12 map-meshable volumes shown below.
(The file jetimp.inp can be used to create this geometry.)
Set ESIZE = 0.2 and map mesh with FLUID142 elements.
The jet Reynolds number is 105.
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Fluid Properties |
Loading 737x233h |
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r=1 |
VZ=-1 |
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m=1.0e-5 |
Pout=0 |
Steady-state
Incompressible
Turbulent
Fluid properties are constant
Dimensions in inches - Fluid is air.
Refer to Elements manual documentation to apply real constant data for fan.
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Water |
10 cm/sec |
Diameter of helium pipe |
1.00 cm |
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He |
40 cm/sec |
Thickness of steel |
0.15 cm |
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OD of water pipe | |||
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(annular thickness of water flow is 0.25) |
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Length |
15 cm |
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Tinlet He |
-20C |
Steel conductivity |
0.536 w/cm-C |
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Tinlet water |
100C |
Steel specific heat |
0.4265 J/g-c |
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Steel density |
7.8332 g/cm3 |
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Specific Heat |
4.8 J/gC | ||
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Water |
r=.963 g/cm3 |
Helium |
Gass Nominal Conditions |
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m=3.057 E-4 |
r=1.67E-3 g/cm3 |
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k=6.8 E-3 |
T=293K |
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p=1.42E-3 |
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m=2.143E-4 |
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