I have been asked to produce some cut plots for a project with isolines that represent a certain gas concentration level (say 20 ppm), with isolines on the plot for every 10 second interval.  The isolines would represent a "concentration front" that shows how far the gas moves at each time interval.  I have attached a .JPG image that illustrates the concept.  I don't see a way to do this in Flow simulation, or even a way to create curves from the isolines.  Any ideas?  Alternatively, has anyone saved the mesh to ASCII and used 3rd-party software to generate plots before?