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Error using optimization module

Posted 2 juin 2016, 21:37 UTC−4 Fluid & Heat, Heat Transfer & Phase Change, Optimization Version 5.2 2 Replies

Shi Zeng
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I tried to simulate a forced convective heat transfer problem: water flow through a heat sink. When I did stationary study with initial values of optimization parameters, it ran well. But if I ran optimization, the following error occurred:
Undefined variable.
- Variable: CFLCMP
- Geometry: geom1
- Domain: 2
Failed to evaluate variable.
- Variable: comp1.spf.locCFL
- Defined as: CFLCMP
Failed to evaluate expression.
- Expression: nojac(comp1.spf.time_step_inv/comp1.spf.locCFL)
Failed to evaluate expression.
- Expression: d(d((comp1.spf.rho*nojac(comp1.spf.time_step_inv/comp1.spf.locCFL)*(-(comp1.u-nojac(comp1.u))*test(comp1.u)-(comp1.v-nojac(comp1.v))*test(comp1.v)-(comp1.w-nojac(comp1.w))*test(comp1.w)))*(dvol),{test@3}),comp1.u)

Anyone got an idea how to shoot this?
Thanks in advance
2 Replies Last Post 15 juil. 2016, 16:05 UTC−4
Shi Zeng
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Posted: 8 years ago 14 juin 2016, 02:21 UTC−4
I found that 'comp1.spf.locCFL' is the pseudo time defined in Laminar flow. By default, in laminar flow-advanced setting, the box for 'use pseudo time stepping for stationary equation form' is checked, and CFL number expression is given automatically. However, it seems my CFL number wasn't given automatically. So I just tick off the 'use pseudo time stepping for stationary equation form', then, it runs well.
However, I still don't know why stationary study can run well while optimization can not previously.
I found that 'comp1.spf.locCFL' is the pseudo time defined in Laminar flow. By default, in laminar flow-advanced setting, the box for 'use pseudo time stepping for stationary equation form' is checked, and CFL number expression is given automatically. However, it seems my CFL number wasn't given automatically. So I just tick off the 'use pseudo time stepping for stationary equation form', then, it runs well. However, I still don't know why stationary study can run well while optimization can not previously.
Trevor Munroe
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Posted: 8 years ago 15 juil. 2016, 16:05 UTC−4
I ran into the same issue. Like you I worked around it.
I ran into the same issue. Like you I worked around it.

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