Tips & Tricks

Calculate Hybrid TL

How does VA One calculate hybrid TL? Hybrid transmission loss is calculated from the transmission coefficient, given by τ12 = 16 pi / A k12 Sumrs [Im{Ddir(2)}rs (Dtot,s-1 Im{Ddir(1)} Dtot,s-H)rs ]

What to consider when projecting TBL data?

Best is to use data in the correct/local plane, so no projection is needed. This will also not introduce approximations regarding the actual flow. However if projection is needed the wave number and decay coefficients should be projected

Amplitudes are incorrect when importing external modes

When importing external modes, the amplitudes are incorrect - what can be the cause?

Radiation Efficiency from HAJ is dependent on loading - is that expected?

This is expected, as the Radiation efficiency will depend on which modes you excite. From help: "For an FE subsystem the radiation efficiency indicates the in-situ radiation efficiency (rather than the radiation efficiency of the resonant modes of the panel). The radiation efficiency of a structural FE subsystem depends on its response (i.e. depends on the loading, damping, coupled subsystems, etc...)."

Using results from the periodic subsystems module in my SEA model

Where do I use results from the periodic subsystems module in my SEA model?

Does using imported NASTRAN damping matrices add much to the solve time?

Import may take some extra time, but this should not be significant. Also, the fully populated damping matrix shouldn't make much difference in the solution time as we don’t use a sparse matrix for the modal matrix. As soon as you have hybrid or many different things that matrix gets fully populated anyway

Apply user defined radiation efficiency

To enforce the radiation efficiency of a shell, you need to modify the coupling loss factor between the shell and connected cavity, or the radiation loss factor

How do I get the hybrid TL using scripting (Python)?

Python can be used efficiently to create scripts, for this articlea sript to calculate the hybrid TL is given as an example

Importing (ANSYS) Modal results - normalization

Care must be taken to ensure that the correct units are selected when importing the modal results,

Difference in Hybrid TL calculated with DAF and SIF's

When the hybrid TL is calculated, the TL will be the same irrespective of the side the NCT is applied,