Hello everyone,
I’m trying to run one of examples called propulsion-6.1.0-2021-06-23_09.44.07.182 available in ValidationCases-6.1.0.zip through this link. My SPIS version is SPIS-6.2.2-win64b.
I’ve noticed a difference in the SPT-100 definition in Group Editor and in SPIS Initialization Summary. For some reason, the temperatures in the Initialization Summary are higher than in Group Editor. I’m attaching a screenshot showing this difference. Can anyone please help me understand why those temperatures are different?
I’m also trying to understand the physics behind the Mach number. I’ve tried using two different equations for the speed of sound (c=sqrt(gamma * R * T / mu), gamma=5/3, and different variations of c=sqrt(k_B * T / mu)), latter were found here). However, so far I couldn’t exactly reproduce the required beam velocity by setting up corresponding Mach number. Can anyone please help me understand the exact definition of the Mach number in this thruster definition model?
Lastly, I’m a bit confused by such large values of ion temperature for the SPT-100 and innerdivergence and divergence angles in Group Editor. If I understand it correctly, in SPIS ions at the thruster exit boundary surface (please correct me if I’m wrong) have both beam velocity (defined through Mach number?) and random velocity components. The latter can be defined through temperature to some point (if we assume a velocity distribution as Maxwellian). So, then, is this temperature responsible for the beam divergence? But if the temperature already defines plume divergence, what’s the meaning of innerdivergence and divergence angles in Group Editors?
I’m still new to SPIS, and I’d be extremely grateful if anyone could help me find the answers to those questions.
Thank you for your support!
All the best,
Egor