shock wave in very high pressure gradients

ndabir · October 24, 2011, 13:42

Hello all,

I want to simulate a shock propagation induced by a very high pressure gradient of inlet and outlet (around 1 Giga Pa).
I am using an explicit solver with first order upwind and with time steps of around 10^(-10) since I just need to model a very short time after shock initiation.
The problem is when this pressure gradient is around 10 MPa, i will have very good results but as I change it to higher pressures, it gives me these errors:

Error > (greater-than): invalid argument [2]: wrong type [not a number]
Error Object: -1.#ind

Error: WorkBench Error: Could not handle event: SolutionStatusUpdate
Error Object: #f

these errors appear after one iteration! does any body have any idea?
is fluent capable of simulating this high pressure gradients?

thanks,

cartman · October 24, 2011, 14:17

I'm not kind of expert but...

1. did you checked solution limits?

2. if you reduce under-relaxtion coefficients, it might be...

3. mesh can occur problems

good luck

cartman · October 24, 2011, 14:19

oh dear lord..

how can I delete this text?

ndabir · October 29, 2011, 13:54

I have checked all of this but this error appears at the first step. any idea?

immortality · February 26, 2013, 18:48

how did you solve the problem?

October 24, 2011, 13:42	shock wave in very high pressure gradients	#1
ndabir Senior Member navid Join Date: Jan 2010 Posts: 110 Rep Power: 16	Hello all, I want to simulate a shock propagation induced by a very high pressure gradient of inlet and outlet (around 1 Giga Pa). I am using an explicit solver with first order upwind and with time steps of around 10^(-10) since I just need to model a very short time after shock initiation. The problem is when this pressure gradient is around 10 MPa, i will have very good results but as I change it to higher pressures, it gives me these errors: Error > (greater-than): invalid argument [2]: wrong type [not a number] Error Object: -1.#ind Error: WorkBench Error: Could not handle event: SolutionStatusUpdate Error Object: #f these errors appear after one iteration! does any body have any idea? is fluent capable of simulating this high pressure gradients? thanks,

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October 24, 2011, 14:17		#2
cartman Member Chris, Kam Join Date: Nov 2010 Location: Busan, South Korea Posts: 42 Rep Power: 15	I'm not kind of expert but... 1. did you checked solution limits? 2. if you reduce under-relaxtion coefficients, it might be... 3. mesh can occur problems good luck

October 24, 2011, 14:19		#3
cartman Member Chris, Kam Join Date: Nov 2010 Location: Busan, South Korea Posts: 42 Rep Power: 15	oh dear lord.. how can I delete this text?

October 29, 2011, 13:54		#4
ndabir Senior Member navid Join Date: Jan 2010 Posts: 110 Rep Power: 16	I have checked all of this but this error appears at the first step. any idea?

February 26, 2013, 18:48		#5
immortality Senior Member Ehsan Join Date: Oct 2012 Location: Iran Posts: 2,208 Rep Power: 26	how did you solve the problem?