Availability of Contures (e.g. Schlieren)
 

Hello,
i have previously run simulations with the density based solver in steady and transient simulations.
Because im mainly working with supersonic flow and the formation of shock waves i like to use contures displaying schlieren.
I setup a new simulation and used the same settings (density based, ideal-gas fluid, kwsst, energy on) and run a simulation on the same mesh, only difference is that in order to initialize my simulation optimally i require my interior to be split into two parts (so one can be standart initialized and one interpolated).
When i now want to creat conture plots in Fluent i do not have the option for schlieren under density.
Is this due to the fluid region being split up into two (connected) interiors or what are other possibilities why i cannot plot this value like i used to do?
I tried to merge the interiors but it didnt help.