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Old   May 17, 2012, 23:43
Default why my momentum and mass not convergence
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Xing Wu
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dear all,



my case is simulate the the fan in an tools, i just want to know the massflow, but i can not get the right result ,since the RMS not convergence even more than 1000 iterations.



the parameters is copied below,




LIBRARY:
MATERIAL: Air at 25 C
Material Description = Air at 25 C and 1 atm (dry)
Material Group = Air Data, Constant Property Gases
Option = Pure Substance
Thermodynamic State = Gas
PROPERTIES:
。。。。。。。。。。。。。。
END
END
END
FLOW: Flow Analysis 1
SOLUTION UNITS:
Angle Units = [rad]
Length Units = [m]
Mass Units = [g]
Solid Angle Units = [sr]
Temperature Units = [K]
Time Units = [s]
END
ANALYSIS TYPE:
Option = Steady State
EXTERNAL SOLVER COUPLING:
Option = None
END
END
DOMAIN: housing
Coord Frame = Coord 0
Domain Type = Fluid
Location = DOMAIN_OF_STATOR
BOUNDARY: Default Fluid Fluid Interface Side 1
Boundary Type = INTERFACE
Location = Primitive 2D AS,Primitive 2D AT,Primitive 2D AU,Primitive \
2D AV,Primitive 2D R,Primitive 2D S,Primitive 2D T,Primitive 2D U
BOUNDARY CONDITIONS:
MASS AND MOMENTUM:
Option = Conservative Interface Flux
END
TURBULENCE:
Option = Conservative Interface Flux
END
END
END
BOUNDARY: baffle
Boundary Type = WALL
Location = BAFFLE
BOUNDARY CONDITIONS:
MASS AND MOMENTUM:
Option = No Slip Wall
END
WALL ROUGHNESS:
Option = Smooth Wall
END
END
END
BOUNDARY: brakets
Boundary Type = WALL
Location = BRACKETS
BOUNDARY CONDITIONS:
MASS AND MOMENTUM:
Option = No Slip Wall
END
WALL ROUGHNESS:
Option = Smooth Wall
END
END
END
BOUNDARY: housing Default
Boundary Type = WALL
Location = HEAT_SINK,MOSFET1,MOSFET2,PCB
BOUNDARY CONDITIONS:
MASS AND MOMENTUM:
Option = No Slip Wall
END
WALL ROUGHNESS:
Option = Smooth Wall
END
END
END
。。。。。。。。。。。。。。
BOUNDARY: inlet
Boundary Type = OPENING
Location = INLET,INLET2
BOUNDARY CONDITIONS:
FLOW DIRECTION:
Option = Normal to Boundary Condition
END
FLOW REGIME:
Option = Subsonic
END
MASS AND MOMENTUM:
Option = Opening Pressure and Direction
Relative Pressure = 0 [Pa]
END
TURBULENCE:
Option = Medium Intensity and Eddy Viscosity Ratio
END
END
END
。。。。。。。。。。。。。
BOUNDARY: outlet
Boundary Type = OUTLET
Location = OPENING
BOUNDARY CONDITIONS:
FLOW REGIME:
Option = Subsonic
END
MASS AND MOMENTUM:
Option = Average Static Pressure
Pressure Profile Blend = 0.05
Relative Pressure = 0 [Pa]
END
。。。。。。。。。。。。。
DOMAIN: rotor domain
Coord Frame = Coord 0
Domain Type = Fluid
Location = DOMAIN_OF_ROTOR
BOUNDARY: Default Fluid Fluid Interface Side 2
Boundary Type = INTERFACE
Location = Primitive 2D AO,Primitive 2D AP,Primitive 2D AQ,Primitive \
2D AR,Primitive 2D AW,Primitive 2D AX,Primitive 2D AY,Primitive 2D AZ
BOUNDARY CONDITIONS:
MASS AND MOMENTUM:
Option = Conservative Interface Flux
END
TURBULENCE:
Option = Conservative Interface Flux
END
END
END
END
CONVERGENCE CONTROL:
Maximum Number of Iterations = 500
Minimum Number of Iterations = 1
Physical Timescale = 0.01 [s]
Timescale Control = Physical Timescale
END
CONVERGENCE CRITERIA:
Residual Target = 0.00001
Residual Type = RMS
END
DYNAMIC MODEL CONTROL:
Global Dynamic Model Control = On
END
END
END
。。。。。。。。。。。。
Memory Allocation Factor = 1.0
END
END
。。。。。。。。。。。。
Attached Images
File Type: jpg momentum and mass.jpg (31.1 KB, 16 views)
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Old   May 17, 2012, 23:52
Default the fluid domain
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Xing Wu
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the fluid domain
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File Type: jpg 5-18-2012 10-49-20 AM.jpg (26.4 KB, 20 views)
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Old   May 18, 2012, 03:01
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Sainath
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Is that a Generator you are trying to model?..
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Old   May 18, 2012, 08:49
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This question is covered by an FAQ:

http://www.cfd-online.com/Wiki/Ansys...gence_criteria
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