Chris Nelson is the Chief Scientist for CFD at Innovative Technology Applications Company, LLC. Recently, one of his focuses has been on solving complex problems in jet noise simulation.
Chris runs his CFD cases on the ITAC computer in Missouri and a host of other remote high performance computing (HPC) systems. The jet noise simulations were mostly run on DOD HPC systems. He generally works from home, so he connects to the remote computer using residential internet. Aeroacoustics requires highly resolved grids and the solution is unsteady, so the resulting set of data files is too large to transfer over the internet to his local computer. The case he used to test Tecplot’s new client-server capabilities had 21 million grid points and flowfield snapshots at each of the 100 time steps.
In the past, Chris used remote display with Tecplot to perform his visualization but, because of network latency, it often performed poorly with his internet connection. Chris says “some time back I spent an oversized chunk of time trying to get a movie generated on one of the HPC sites using Tecplot. The remote systems would run Tecplot and display (very slowly) the frame-by-frame creation of the animation…” He was also frustrated that the HPC system only had older versions of Tecplot that didn’t generate correct animation files, and that newer versions were not installed as quickly as he needed. Chris says, “client-server lets you take control of the version of Tecplot that you use.”
Tecplot’s SZL Server Solution
A client-server version is available in Tecplot 360 2017 and later releases. The system uses Tecplot’s SZL (subzone load-on-demand) technology to transfer only those subzones (small pieces of volume data) from a server on the remote computer to Tecplot 360 on the local computer. In most cases, this dramatically reduces the amount of data sent over the network. For the jet noise example, only 1% of the volume data file must be transferred to generate Chris’ animation.
Chris was an early tester of Tecplot’s SZL Server and had this to say: “Doing things with SZL Server will be both faster to display and will also completely get around the issue of weird install glitches on the remote site (for the version set up out there).”
The SZL Server works only with SZL format (*.szplt) files, so Chris is converting his PLOT3D files to *.szplt files on the remote computer. Chris: “It’s a lot easier to do a file conversion up where all the data is and then run SZL Server than to have to download everything to a local system and run local Tecplot 360 or try to run Tecplot 360 in a fully remote mode on the server.”
Tecplot’s SZL Server technology allows users to analyze and visualize large remote datasets. SZL Server is available to Tecplot 360 licensees with a TecPLUS subscription.