validation data for high pressure transient gas injection
 

I am performing high Pressure gas injection into a chamber, having pressure ratios typically of order 10 and higher; and below 1mm injector diameter (a single hole constant diameter one).
In such pressure Ratios, the flow is Under-expanded, i.e. mach number at nozzle exit becomes unity and flow downstream from the nozzle becomes supersonic with a very complex pattern.
I need data to validate the solution in the near field but I can not find any! So I was wondering if anybody would help me.
I could not find any suitable Numerical or experimental data on the case in the literature, and I am trying to find theoretical data or method of characteristics calculations for such a case.
Any information about the case would be appreciated.