Propulsion

The coupling of mesoscale and CFD model capabilities allows to obtain a more accurate and powerful tool for wind knowledge and forecasting. CFD is able to model the details of flow around specific geographic and man-made features; mesoscale models incorporate information about the outer scale geophysical variability (evolving boundary conditions and assimilation of external data).

A model based on boundary conditions provided by a mesoscale model and fine-scale topographic features modelled in CFD is currently under development.

Some of the phases of an aircraft mission are easily predictable. When aircraft trajectory is known, differences between expected and real path can be due to meteorological conditions. Dedicated filters can be used to deduce the wind field from large dataset of real trajectories. The method is completed with meteorological models to obtain better initial estimations and with real time measurements to improve accuracy.

Development of flight dynamic models to be run under simulated environmental conditions and with manual or pre-programmed inputs from the user. The software is prepared:

• as a tool for engineers to test different flight configurations
• as a tool for engineers to test different control strategies
• as a tool for operators for training purposes

 The aerodynamics, structural and propulsion performance of the vehicle are modelled or tested and included in the simulation.

The ascent optimal trajectory for small launchers can be calculated for injection at maximum orbital height with autonomous rapid corrections in real time. The angle of thrust vector -the single control- can be solved together with some system design parameters by applying an indirect optimization method iterated over the parameter space. Feasibility, accuracy and convergence of the method are part of the research, as well as necessary throughput.

On-design and off-design performance is also investigated to help present and future designs of aero-ejected launchers