negtive density
 

Trying to run transient analysis, the run stop after

the first iter. message is like

STEP UVEL VVEL WVEL MASS T EN DISS ENTH U V W P TE ED T

1 1.93E-02 2.41E-05 6.43E-02-4.74E-02 9.69E-01 7.81E+03 1.36E+04 -1.86E+00-6.49E+00 1.63E+02 1.28E+03 2.24E+02 1.99E+06 6.02E+02 Warning - starwatch daemon is not registered, no information sent to starwatch.

*** ERROR #076 *** NEGATIVE DENSITIES FOUND AT MORE THAN 100 CELLS. RUN STOPPED

what wrong of my model set-up

Re: negtive density
 

Hi

Does your time step meet the courant equation?

(Cr = (v * t)/L ,where Cr = Courantnumber of a cell, v = velocity of fluid in this cell (compressible: velocity of fluid + speed of sound), t = time step and L is the length of this cell)

The max. Cr shouldn't exceed 50 - 100.

Re: negtive density
 

If you do have moving mesh (events module) you may try to reduce the time step length.

Re: negtive density
 

Another thing to you and to the others who has the same problem you may try the MARS differencing scheme and don't ask me why because I don't know why but it works.