Tips & Tricks

What is the Sturm sequence?

It provides a quick way to calculate the number of local modes in an FE subsystem without performing a detailed Eigen solution (which is much costlier).

Difference in performance and requirements when solving in the GUI vs. in batch

Is there a difference in performance and requirements when solving in the GUI vs. in batch? Yes, there is a difference in how data is saved in the solve process.

Applying anechoic termination to a muffler tailpipe modeled with FE acoustics

To apply an anechoic termination, disconnect the SIF from the FE Face, then go to ...

Introduce a reflection coefficient on an infinite plane in VA One

How can I introduce a reflection coefficient on an infinite plane in VA One? One workaround is to use the following approximate procedure.

I'm trying to override properties for a fuselage section, but it’s hard to get TL to match - can you give advice?

In a pure SEA model, overriding modal density and radiation efficiency (i.e. CLF) normally gives good correlation to a hybrid model. For the resonant path, if the CLF, MIB and DLF are the same, one would expect the same answer. If not, discrepancies may come from the non-resonant path which do not get overridden by the manipulations above.

What's the requirement for GLIBC and VA One?

The fundamental requirement for VA1 and any Linux OS is based around the GLIBC version. We require GLIBC 2.12 or better for VA One 2014.5. This includes RHEL6+, Centos 6+

Reading mass matrix from an op2 file

Is there a way to read a mass matrix from an op2 file?, This is not yet implemented in VA One, but is under consideration

Using Nova in batch mode

Can Nova be used in batch mode?, Yes, one can launch NOVA with a specific file

Can I use OpenFoam on Linux to solve for non-uniform mean flow in VA One?

Yes, write out the input files for OpenFoam from VA One, solve on Linux, and then import the results into VA One. Note: The Linux version of OpenFoam is available on the OpenFoam website, not on the VA One media.

How do I solve in two different models and glue results back together?

This is an example of how to use the new functionality in VA One 2014.5