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Old   April 11, 2008, 19:13
Default high cambered airfoil SST CFX
  #1
Henrique Schumann
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Hi,

I have been trying to validate a profile of high cambered in Re=300000. I have been using the soft CFX, with hexa mesh(y+ <3), the model SST with Gamma Theta Model plus Transition Model Revision = 0.

I have had good results for Cl but i am still having some difficulties with the Cd.

how could i improve this result?

Ps.: I'm a student from BRAZIL.
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Old   April 11, 2008, 21:28
Default Re: high cambered airfoil SST CFX
  #2
Rogerio Fernandes Brito
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Vc está comparando com dados experimetais? e suas condições de contorno?
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Old   April 12, 2008, 00:50
Default Re: high cambered airfoil SST CFX
  #3
Henrique Schumann
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Sim! estou comparando com os dados da UIUC do perfil Selig1223, e com os dados fornecidos pelo programa xfoil. As condições de contorno são as seguintes: INLET - Cartesian Velocity Components TURBULENCE:

Eddy Length Scale = 0.305 [m](corda do aerofoil)

Fractional Intensity = 0.009

Option = Intensity and Length Scale OUTLET:

Option = Average Static Pressure

Relative Pressure = 0 [Pa]

END

PRESSURE AVERAGING:

Option = Average Over Whole Outlet AEROFOIL: WALL - no slip e SYMMETRY para as laterais. Tenho dúvidas com relação a turbulência no Inlet, e o Length Scale, pelo PDF do UIUC a turbulencia usado no túnel de vento seria de 0,1%, mas para esse valor não consegui obter bons resultados.
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Old   April 12, 2008, 06:54
Default Re: high cambered airfoil SST CFX
  #4
Rogerio Fernandes Brito
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Try these settings:

BOUNDARY: Inlet

Boundary Type = INLET

Location = Inlet

BOUNDARY CONDITIONS:

FLOW REGIME:

Option = Subsonic

END

MASS AND MOMENTUM:

Option = Cartesian Velocity Components

U = XX.X [m s^-1]

V = YY.Y [m s^-1]

W = 0 [m s^-1]

END

TURBULENCE:

Option = Medium Intensity and Eddy Viscosity Ratio

END

END

END

BOUNDARY: Outlet

Boundary Type = OUTLET

Location = Outlet

BOUNDARY CONDITIONS:

FLOW REGIME:

Option = Subsonic

END

MASS AND MOMENTUM:

Option = Average Static Pressure

Relative Pressure = 0 [Pa]

END

PRESSURE AVERAGING:

Option = Average Over Whole Outlet

END

END

END

BOUNDARY: Symmetry1

Boundary Type = SYMMETRY

Location = Symmetry1

END

BOUNDARY: Symmetry2

Boundary Type = SYMMETRY

Location = Symmetry2

END

DOMAIN MODELS:

BUOYANCY MODEL:

Option = Non Buoyant

END

DOMAIN MOTION:

Option = Stationary

END

MESH DEFORMATION:

Option = None

END

REFERENCE PRESSURE:

Reference Pressure = 1 [atm]

END

END

FLUID MODELS:

COMBUSTION MODEL:

Option = None

END

HEAT TRANSFER MODEL:

Fluid Temperature = 7.7 [C]

Option = Isothermal

END

THERMAL RADIATION MODEL:

Option = None

END

TURBULENCE MODEL:

Option = SST

TRANSITIONAL TURBULENCE:

Option = Gamma Theta Model

TRANSITION ONSET CORRELATION:

Option = Langtry Menter

END

END

END

TURBULENT WALL FUNCTIONS:

Option = Automatic

END

END

END

DOMAIN INTERFACE: Domain Interface 1

Boundary List1 = Domain Interface 1 Side 1

Boundary List2 = Domain Interface 1 Side 2

Interface Type = Fluid Fluid

INTERFACE MODELS:

Option = Translational Periodicity

END

MESH CONNECTION:

Option = Automatic

END

END

INITIALISATION:

Option = Automatic

INITIAL CONDITIONS:

Velocity Type = Cartesian

CARTESIAN VELOCITY COMPONENTS:

Option = Automatic

END

K:

Option = Automatic

END

OMEGA:

Option = Automatic

END

STATIC PRESSURE:

Option = Automatic

END

END

END

OUTPUT CONTROL:

RESULTS:

File Compression Level = Default

Option = Standard

END

END

SOLVER CONTROL:

ADVECTION SCHEME:

Option = High Resolution

END

CONVERGENCE CONTROL:

Length Scale Option = Conservative

Maximum Number of Iterations = 2000

Timescale Control = Auto Timescale

Timescale Factor = 1.0

END

CONVERGENCE CRITERIA:

Residual Target = 0.000001

Residual Type = RMS

END

DYNAMIC MODEL CONTROL:

Global Dynamic Model Control = On

END

END END COMMAND FILE:

Version = 11.0

Results Version = 11.0 END EXECUTION CONTROL:

INTERPOLATOR STEP CONTROL:

Runtime Priority = Standard

EXECUTABLE SELECTION:

Double Precision = Off

END

MEMORY CONTROL:

Memory Allocation Factor = 1.0

END

END
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