I need to help solving supersonic transverse flow and error
 

Dear all,

I'm doing a analysis of supersonic transverse flow with stinger shape injector. but i have lot of problem which is occured by error

My problem is a compressible and 2 inlet and 1outlet. The conditions given to my problem are

mainstream(air)

• Total pressure at the inlet is 800000 Pa
• Static pressure at the inlet is 21778 pa (M# : 3.0)
• Static pressure at the outlet is 21778 Pa
• Total temperature is 300 K
• Isentropic and Ideal gas

Injector(helium)

• Total pressure at the injector inlet is 10138669 pa
• Static pressure at the injector outlet is 493847.8 Pa (M# : 1.0)
• Total temperature is 300 K
• Isentropic and Ideal gas
• Ideal gas

Model

• Energy Equation
• viscous - SST k-omega
• Species - Species Transport

but, when I analize this problem, I faced this error

temperature limited to 1.000000e+00 in 7 cells on zone 16
time step reduced in 10 cells due to excessive temperature change
(My coorant Number is 0.5, and also Positivity rate limit is 0.4)

I want to know why this error is occured and how to solve this error.

I wonder if there is anyone who could help me.

Thanks,

LJH