March 8, 2010, 17:04
thermophysicalProperties for nitrogen
Join Date: Jan 2010
Rep Power: 7
while simulating some supersonic flow of nitrogen I'm having some problems with the thermodynamic properties... As I'm not having acccess to Janaf-tables or something like that I was hoping you could help me out with some thermodynamicProperties-file?
It's all about pure nitrogen (N2), the temperature range is from at least 40K to 8,000K. (Just a guess...)
For those who want to know:
Here's a short description of my problem:
- There are two inlets, one that is pointing (almost) directly to a vacuum-outlet and therefore the flow in that nozzle is reaching very low temperatures (about 50K, determined from an other simulation).
- The second inlet is facing towards a wall, what as a consequence causes the temperature to go very high at this point.
- The initial temperature is set to 300K everywhere.
- I'm using the sonicFoam-solver as that is all in supersonic-range.
What I have done so far:
- I was using the constThermo-modell. The simulation crashes when temperature at second inlet reaches 5,000K. According to some other posts that seems to be some magic value limiting the constThermo-model. Makes sense somehow because heat-capacity is not constant... Either way, the simulation stops, and that's bad.
- I was using the janafThermo-modell. The coeffs I got from the ???-tutorial (don't remember the excact name anymore). The temperature-ranges are set to 100K < 1,000K < 10,000K. The simulation crashes when temperature at first inlet is falling below the 100K.
As both inlets are connected through a small channel and I'm interested in density-gradient inside this channel I can not treat the two inlets independend...
So now I'm hoping that someone got access to janaf-tables or has some thermophysicalProperties-file I could use...
Or, what would even better: That someone can tell me where to get those information by my own...
Thanks a lot,