Turbulent Boundary Layer Model dialog box

Transient Mesh Selection
Select VATV Faces	Specifies the fluid face selection. All VATV FacesSelects all fluid faces of the VATV.Custom RegionYou select only the fluid faces you desire.
Correlation Spectrum Definition
Model	Allows you to select correlation spectrum models. You can enter spectrum-related parameters in the Parameters group, after you select one of the following models:CorcosThis model is especially useful for accurately predicting the spectrum convective ridge for high-speed flows, and for its simple formulation. You need to only adjust the Correlation Decay Rate (alpha) and Correlation Decay Rate (beta).EfimtsovThis is the only model in Simcenter 3D that was developed from aircraft instead of laboratory measurements. This model was validated with measurements on an aircraft that was traveling at speeds above Mach 0.41 and below Mach 2.1.ChaseThis model provides a direct formulation for the wall pressure spectrum because it is not defined as a product of a correlation and auto-spectrum model.User DefinedThis model allows you to define your own model with a field.
Auto-Spectrum Definition
Model	Allows you to select auto-spectrum models that are one-sided in Simcenter 3D. That is, the software considers only positive frequencies. Therefore, all input and output spectra are one-sided quantities.You can enter spectrum-related parameters in the Parameters group, after you select one of the following models:**Robert (Corcos)**This model is especially useful for accurately predicting the spectrum convective ridge for high-speed flows, and for its simple formulation. You need to only adjust the Correlation Decay Rate (alpha) and Correlation Decay Rate (beta).EfimtsovThis is the only model in Simcenter 3D that was developed from aircraft instead of laboratory measurements. This model was validated with measurements on an aircraft that was traveling at speeds above Mach 0.41 and below Mach 2.1.GoodyThis model is limited to zero pressure gradient flows but considers the effect of the Reynolds number variations through the time scale ratio. This model shows good agreement with experimental data over Reynolds numbers above 1400 and below 23400.SmolyakovThis model is a semi-empirical model and mostly applicable to flat plate surfaces.Cockburn-RobertsonThis model is used for flows at transonic and supersonic speeds. The model was calibrated when investigating the vibration response of spacecraft shrouds to in-flight fluctuating pressures. The effects of the Mach number affect only the mean square pressure, and become negligible at transonic and lower speeds.Smolyakov-TkachenkoThis model is a semi-empirical model and mostly applicable to flat plate surfaces.Chase-HoweThis model is limited to near or below the universal range of a quantity, which is a function of frequency, fluid viscosity, and wall friction velocity.User DefinedThis model allows you to define your own model with a field.
Parameters
Lets you enter parameter values for your combination of correlation and auto-spectrum models. Depending on the selected models, only specific parameters are available.
Lets you enter parameter values for your combination of correlation and auto-spectrum models. Depending on the selected models, only specific parameters are available.Note: You can find valid parameter values in the literature, or obtain them from experiments or previous simulations.The software does not check the parameter values; therefore you must enter only valid values. For example, fluid density, displacement thickness, decay rates, and so on cannot be zero or negative.You must specify convective velocity parameters for all TBL models, even if you use a User Defined correlation spectrum model which may contain information about convective velocity in a user defined .dll file.
Appears when you choose Robert (Corcos), Efimtsov, Goody, Smolyakov, Cockburn-Robertson, Smolyakov-Tkachenko, Chase-Howe, or User Defined.
Convective Velocity (X)	Sets the uniform mean flow velocity in the model X axis.
Convective Velocity (Y)	Sets the uniform mean flow velocity in the model Y axis.
Convective Velocity (Z)	Sets the uniform mean flow velocity in the model Z axis.
Correlation Decay Rate (alpha)	Sets the longitudinal coherence decay rate.
Correlation Decay Rate (beta)	Sets the lateral coherence decay rate.
Appears when you choose Robert (Corcos), Goody, Smolyakov, Cockburn-Robertson, Smolyakov-Tkachenko, or Chase-Howe.
Fluid Outer Velocity	Sets the fluid velocity outside the boundary layer.
Appears when you choose Robert (Corcos), Efimtsov, or Cockburn-Robertson.
Fluid Density	Sets the fluid density.
Appears when you choose Efimtsov, Goody, or Smolyakov.
Wall Friction Velocity	Sets the constant wall friction velocity, or shear velocity, within the boundary layer.
Appears when you choose Efimtsov, Goody, or Cockburn-Robertson.
Boundary Layer Thickness	Sets the fully developed boundary layer thickness.
Appears when you choose Goody, Smolyakov, or Smolyakov-Tkachenko.
Wall Shear Stress	Sets the dynamic pressure (wall shear stress).
Appears when you choose Robert (Corcos).
Displacement Thickness	Sets the distance the external flow is displaced outwards due to the decrease of velocity in the boundary layer.
Appears when you choose Goody or Smolyakov.
Fluid Viscosity	Sets the fluid viscosity.
Appears when you choose Smolyakov.
Momentum Thickness	Sets the distance by which the boundary layer is displaced to compensate for the reduction of fluid momentum caused by boundary layer formation.
Appears when you choose Cockburn-Robertson.
Speed of Sound	Sets the fluid speed of sound.

For more information on correlation spectrum and auto-spectrum models, see Turbulent Boundary Layer Models.

How do I

Create a Random VATV Forced Response solution

Learn more

Random VATV Forced Response

Quick links

Command reference

Pre/Post video examples

Bulk Entry Descriptions

Simcenter 3D tutorials

Browse Simcenter 3D help by product area

Turbulent Boundary Layer Model dialog box, Simcenter 3D 2021.1 Series

© 2020 Siemens

window.mainLanguage="en_US"

window.delivId=""

window.projectId=""

MathJax.Hub.Config({ TeX: { extensions: ["autoload-all.js"] }, tex2jax: { displayMath: [ ] }, "SVG": { scale: 125 } });