Symptoms

Models run in GateCycle version 5.31 generate many more equipment (property) warnings than in previous versions. The error log contains many messages like the following:

• ** WARNING — Maximum iterations exceeded in (GASTfromPS) T calcs from P and S leaving SCNTGUES with INDEP= 53.299 and difference = 5.6624e-007

Cause

Specifying a lower than default property tolerance can lead to situations where certain property sets cannot reach the desired level of accuracy for certain state points. These situations are most likely to occur in models that use GTCOMP and/or GTTURB icons, since GateCycle version 5.31 has modified calculation algorithms for these two pieces of equipment.

Resolution

The property warnings should not greatly influence your results. Take one of the following actions to eliminate these errors:

1. Switch the gas property method to JANAF table Data Curves.
2. Raise the property tolerance setting slightly or reset it to the default value of 0.0001.
Note: the property tolerance must always be less than the desired system tolerance.
3. Ignore the warnings and select "Keep your current settings."

Options 2 and 3 should not significantly influence the calculated results.

For More Information

• Upgrades
• Samples
• FAQs
• GT Data Curve Sets

Related Links

• Customer Success Stories
• Orbit Magazine