Tips & Tricks

Note on memory issue for VA One on SUSE
(SLED= SUSE Linux Enterprise Desktop) We have been tracking an issue with SLED 11 SP 2 No handler for exception: ObjectStore internal error Fatal error Cannot allocate memory(errno = 12) mmap failed: reservation addr (nil), len 0x746a520000, prot 0, fd 4, share 1 off 0
Emna Ben Ali Vibro-Acoustics

Whats does ObjectStore internal error - No locks available - mean?
I'm getting this error when solving on Linus, what can be the cause: ObjectStore internal error misc osfs error misc osio error Fcntl (F_SETLK, F_RDLCK) /appl/vaone2013/CInterface_schema.adb: No locks available (err_internal) Execution Completed They are probably running VA One from a NFS share /appl that does not have the right sharing permissions or capabilities.
Emna Ben Ali Vibro-Acoustics

Why can not different users on a pc use the GRID module in VA One 2013?
Different users are using the VA One on a PC, each user logs in using their own ID. However, only the user can use grid BEM who installed Python Developer Kits. Why is that and what can be done?
Emna Ben Ali Vibro-Acoustics

Radiation efficiency for a trimmed panel
How does VA One calculate radiation efficiency for a trimmed panel?, The process is that we compute a radiation efficiency analytically of the bare panel, then compute ...
Emna Ben Ali Vibro-Acoustics

Getting the DLF for a foam
How do I get the DLF for a foam? The loss factor is defined as...
Emna Ben Ali Vibro-Acoustics

DLF>1 when damping computed "from NCT"
This can be due to a bad conditioning of the transfer matrix used by foam module to calculate the NCT impedance to submit to the panel.
Emna Ben Ali Vibro-Acoustics

Getting Cosmic run error
I get a Cosmic run error - what may be the cause? First look at the log file, to see if there is any errors or warnings.
Emna Ben Ali Vibro-Acoustics

FE area junctions : Why is my FE area junctions discontinuous?
Its most likely due to the nature of the meshes. A fundamental assumption for FE->FE Acoustic junctions is that the FE mesh must be finer than the acoustic mesh
Emna Ben Ali Vibro-Acoustics

What is the difference in TL from the VTL and Effective TL?
The difference is that with Effective TL you select a single area junction and with VTL you select a set of panels. The only practical difference is in the area of the connection between the cavities
Emna Ben Ali Vibro-Acoustics

Why is TL dependent on the size of the panel? Shouldn't TL be independent of the shape and size of the panel?
There are some small area/perimeter dependencies in CLFs through a panel but these should usually only cause small differences. Basically, when calculating non-resonant TL AutoSEA2 needs an expression for the impedance of the fluid on either side of the panel
Emna Ben Ali Vibro-Acoustics