[3nhu1]

Hi, thank you for all your help in this forum previously as it has been massive.

Recently I used the tutorial provided here https://innovationspace.ansys.com/kn...g-userfortran/ to get the value of an expression at the previous timestep without using UserFortan or Update Loop = TRANS_LOOP, this was by using a monitor point and arithmetic sum method. I have managed to use this to get the value of p(t-1) and q(t-1) for the previous timestep and from monitoring these points this works nicely!

However I have 2 very small outlets, which makes initialisation important. I've had to run a steady simulation first, getting some variables (table below). The steady simulation also finished with the p(t) and q(t) current timestep which can be initialised. But I also defined the p(t-1) and q(t-1) terms to be initialised when starting the transient simulation as these values default to 0 by the solver otherwise and the poor initial guess for q(t-1) will cause pressure at the 2 small outlets will diverge.

(Table from steady solution end)
| Courant Number | 2.27E-05 | 5.65E+02 |
| Density | 1.06E+03 | 1.06E+03 |
| Pressure | 7.91E+03 | 8.31E+03 |
| pout0prev | 8.31E+03 | 8.31E+03 |
| pout1prev | 8.31E+03 | 8.31E+03 |
| pout2prev | 8.31E+03 | 8.31E+03 |
| qout0prev | -9.59E-07 | -9.59E-07 |
| qout1prev | 1.13E-06 | 1.13E-06 |
| qout2prev | 1.39E-06 | 1.39E-06 |
| Velocity | 5.53E-10 | 7.13E-01 |
| Dynamic Viscosity | 4.00E-03 | 4.00E-03 |

Now I then set up the transient model, having created an AV for qout0prev so this can be used, but I am now getting this error. (please see outfile)

This is the error The parameter 'Expression Value' is defined to be Single Valued but it depends on the field variable: qout0prev Error processing expression: Expression Value = pout0

I define pout0 = ((areaAve(pout0prev)@OutAorta*(cp0*res0d/dt)) + (res0d*(qout0*(1+(res0p/res0d)+(cp0*res0p/dt))- (qout0prev)* (cp0*res0p/dt))))*(1/(1+(cp0*res0d/dt)))

qout0 = -massFlow()@OutAorta/1060 [kg/m^3]
qout0prevvalue = probe(Expression Value.Arithmetic Sum)@MPcurrentoutletflow - probe(Expression Value)@MPcurrentoutletflow

And an AV qout0prev to be equal to qout0prevvalue


Question
1. How do I fix this? Is there a function to make a field variable single valued?
2. On another question on initialisation, I understand checking continue history from when using a previous res file carries over the convergence history and iteration counters, does it carry additional initial conditions versus when that box is not checked?
3. Alternatively is it possible specify a "Value" for qout0prev by editing def file in command editor using like this https://ansys13.ansys.com/KnowledgeA...13/676913.pdf?

Thank you!