Colloquium: Riccardo Bunt (Space Flight)

13 december 2019 09:30 - Locatie: Lecture Room F, Faculty of Aerospace Engineering, Kluyverweg 1, Delft

Re-entry vehicle aerodynamic database reconstruction from the analysis of test dynamics

An aerodynamic database collects dimensionless coefficients that describe the interaction of the vehicle's geometry and airflow; an accurate estimate of its elements is key to the correct modelling of the accelerations experienced during flight. The methodology elaborated is based on the analysis of simulated data from wind tunnel tests and drop tests of a Hayabusa type capsule in subsonic flow regime. The preliminary estimate of the coefficients computed by linear regressions is introduced in data smoothing models in order to reduce noise and errors. The performance of nonlinear regression by optimisation is then investigated on the smoothed dataset. Multi-island Genetic Algorithm, Adaptive Simulated Annealing, Nealder & Mead Downhill Simple, Hooke-Jeves Direct Search and a Hybrid Algorithm have been applied. From the analysis of the results, three algorithms emerge for greater accuracy in the reconstructed database: the Hybrid Algorithm, the Hooke-Jeves Direct Search and the Adaptive Simulated Annealing method.