I ran into an issue where trying to simulate motors using Nakka propellants (KNSB/KNSD/KNSU) produces nonsense instead of meaningful results. I verified the same motor simulation in another program (Meteor), and the results there are roughly consistent with experimental data.

I also tried simulating the motor with other propellant types in OpenMotor itself, and while the results are obviously not optimal (since the motor wasn’t designed for them), they still make sense.

Additionally, I noticed that the burn parameters for these propellants in OpenMotor’s propellant editor do not match the data published on the Nakka website.

The first image shows an OpenMotor simulation of a motor using KNSB propellant. The second image is the same motor simulated with Cherry Limeade propellant. The third image shows the simulation results of an equivalent KNSB motor in Meteor.