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SolverWarning regarding chem_eq.n and chem_eq.n_moles

Open JacobCadrinAubin opened this issue 11 months ago • 1 comments

Hello, I created a model of a mixed flow turbofan based on the example mixedflow_turbofan.py. I was wondering, if I was the only one with this type of SolverWarning. I have this SolverWarning for most of the subsystems in my model.

SolverWarning:'TOC.fc.conv.fs.totals.base_thermo.chem_eq.n' exceeds lower bounds Val: [ 3.23319235e-04 -6.93045815e-01 6.93056829e-01 -1.94550524e+00 -1.84582643e-02 2.56388425e-01 4.17449195e-02 8.59872963e-01 -1.26676179e+00 -1.56866929e-02] Lower: [1.e-10 1.e-10 1.e-10 1.e-10 1.e-10 1.e-10 1.e-10 1.e-10 1.e-10 1.e-10]

SolverWarning:'TOC.fc.conv.fs.totals.base_thermo.chem_eq.n_moles' exceeds lower bounds Val: [-2.08807134] Lower: [1.e-10]

JacobCadrinAubin avatar Jan 15 '25 19:01 JacobCadrinAubin

Hello @JacobCadrinAubin, although I am working with another file, when changing the design and off-design points of the high_bypass_turbofan.py example, I ran into similar situation that you described. What worked for me was to change the off-design points a bit and set them closer together - meaning that the altitude and Mach number changes from one off-design condition to the next needed to be less abrupt. My understanding is that finding a solution to a highly non-linear problem like this has also an art component to it... :)

Hope this helps.

flight-test-engineering avatar Feb 07 '25 12:02 flight-test-engineering