feat: add simple coaxial model to calculations with upstream velocities
- adapt multi-rotor model to calculations
- integration of a simple model for wake radius in updateupstreamvel.m using previous rotor thrust, flow and radius
- adapt bemt.m to this model
- add massflow (flow calculated by indvel.m) in ElemPerf.m massflow is set as a dependent property
- add property flow in OperRotor.m as integral of massflow (see calcperf method)
Edited by Rakotondratsimba Lyraie