Converging Errors in mathematical model of UAV launcher.

I have modelled a UAV launcher based on Alexander Khrulev's paper "Analysis of Pneumatic UAV Launcher Parameters" 2023, which is an open-source paper available at ScienceDirect. I am getting different errors, but the most concerning is that my temperature drops to 0K during working, leading to errors as well as unrealistic behavior. The system consists of 4 differential equations which are tightly coupled, so I am having trouble locating exactly where the problem is. I suspect the problem is in gas dynamics modelling, especially in the intermediate "phi" and "leakage flow rate dm/dt" modelling in the pressure subsystem. I have attached the paper, my workspace as well as my Simulink model in case someone wants to have a look or guide me through this problem. I will be most thankful.

[Yifeng Tang]

After comparing the equations in the paper and your implementation in Simulink, I didn't notice any discrepancy.

One thought after reading through the equations in the paper: eqn (30) describes the "leakage" and the RHS seems to be always positive. But the variable m seems to represent the mass in a volume in eqn (22,24,25, ...), so I wonder whether there is a sign error. I don't know enough about these governing equations to say for sure. Maybe you'll know :)

[Yifeng Tang]

Or, if you decide to model this in Simscape, I may be able to help a bit more ;)

[Muhammad Talha]

Thank you for giving this problem your valuable time. I will check what you pointed out to. And regarding Simscape, I have modelled it in Simscape and works fine. The idea was to "tune" the Simscape and Simulink models, setting the foundations of a model-based Digital Twin with sensor integration down the lane.