Backward Compatibility with Version 4.3

The default model List has been removed

Heat transfer physics interfaces no longer have the default model list. This list was used to change the default feature for heat transfer models. You can obtain a similar result by adding the corresponding domain feature immediately below the default feature and setting its domain selection to All domains.

Any model files for Java® that modify the default model value require a manual update.

Improved stabilization of HEAT TRANSFER IN SOLIDS

The streamline diffusion stabilization for Heat Transfer in Solids and Biological Tissue features has been improved. It now accounts for contributions from linear source terms from the Heat Source, Out-of-Plane Convective Cooling, Out-of-Plane Radiation, and Out-of-Plane Heat Flux features. This improves the robustness of the convergence when these contributions are large. This change may modify the convergence behavior of existing models.

Frame Selection in discretization section

The Frame type list, which was previously available when a moving mesh was detected, has been removed. The frame type is now controlled by the features.

Update of feature variable names

In order to avoid name conflicts between feature variable names, some of them have been renamed. This change concerns contributive features. Because they are contributing, it is possible to have similar features active on the same boundary. To make it possible to distinguish the variables from each feature, the feature scope has been introduced in the variable name so that variable names now use a prefix. These changes affect the following feature variables:

•

Heat flux

•	Out-of-plane heat flux

•	Convective cooling

•	Out-of-plane convective cooling

•	Boundary heat source

•	Heat source

•	Line heat source

•	Point heat source

•	Edge heat flux/Point heat flux

•	Electrochemical reaction heat flux

•	Reaction heat flux

For example, in a Boundary Heat Source feature, ht.surf has been renamed into ht.bhs1.surf (assuming that ht is the physics interface tag). In the Heat Flux feature, the variable that was previously named ht.q0_hf1 is now ht.hf1.q0.

Any model files for Java® that use the old variable names in expressions (such as expressions used for plotting or data evaluation that include such old variable names) need to be updated manually.

new default Fluid features and opaque subfeature

All MPH-files created in version 4.3 are converted to appear and behave the same way as in 5.0 or a later version.

Due to these new default features, model files for Java can be simplified. In addition, model files for Java that add the Fluid feature or the Opaque subfeature with the default tag require a manual update to avoid duplicate tag conflicts.

Weak Constraints Update for Fluid Flow User Interfaces

The weak constraint formulations for some boundary conditions in the following interfaces have been updated:

•	Laminar Flow

•	Turbulent Flow, k-ε

•	Turbulent Flow, Low Re k-ε

•	Non-Isothermal Flow

•	Conjugate Heat Transfer

See the CFD Module release notes for details.

Weak constraints for the Interior Wall feature are no longer available.

Revision to the Turbulence Models

The formulations of some variables in the turbulence models have been revised in order to improve accuracy. Simulations using a turbulence model can display a different convergence behavior in versions 5.0 and later compared to version 4.3, and the numerical result can differ slightly between the versions.