Semi-free oscillation method for dynamic stability characterization on re-usable launcher first-stage
Creators: name:  S. PARIS 
name:   A. VILADEGUT 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: REUSABLE SYSTEMS
FLIGHT PHYSICS
DYNAMICS

description: Semi-free oscillation method for dynamic stability characterization on re-usable launcher first-stage PARIS Sebastien1* and VILADEGUT Alan1 1von Karman Institute for Fluid Dynamics, Aeronautics and Aerospace Dept., 72 Chaussee de Waterloo, B-1640 Rhode-Saint-Genese, Belgium, *sebastien.paris@vki.ac.be Abstract Interest in new strategies for launch services dedicated to micro-satellites (250 kg) is growing over the world. The development of new launch solutions based on re-usable first stages is paving the way to a more flexible, costly efficient and environmentally friendlier strategy that satisfies the needs of small satellite market. In this framework, the Recovery and Return-to-Base (RRTB) project [1] is conceived by a consortium of leading European companies and institutions to explore a novel technology aiming at recovering the first stage of the MESO launcher. As one of the partners within this consortium, the von Karman Institute (VKI) contributes to the generation and validation of an aerodynamic database using wind tunnel experiment. The vehicles stability in transonic and supersonic is critical for the trajectory estimation [2]. The development of a new semi-free oscillations method to measure the damping parameter of the system is presented. The method is based on the work of Kovacs et al. [3], in which a system of springs and cables were attached to a slender body and routed outside the test chamber to characterize the dynamic response of the system. The present work focus on the minimization of the interactions between the supporting devices and the air flow by using internal springs. The dynamic response of the system is captured with a high-frequency magnetic encoder, which ease the data processing and provides better accuracy than the high-speed cameras used in the past. The design and manufacturing process of the system is described. The similitude rules and the processing method used in this project are explained. A parametric study using springs with different stiffness gives the sensitivity to the natural frequency of the launcher. Static pitching moment coefficients and associated damping coefficients are measured in transonic and supersonic regime. The outcomes of the test campaign shows that results are repeatable and within acceptable uncertainty margins. References [1] Rasmus Bergstrom, Nicola Palumbo, Laura Marti Ramos, Bart Van Hove, Giovanni Medici, Alan Viladegut, Sebastien Paris, Maximilian Soepper, Pranav Bhardwaj, Dimitrios Rellakis, Panagiotis Trifa, Athanasios Dafnis, Marco Kanngieszer, Stefano Piacquadio, A novel design approach for a reusable vtol micro launch vehicle, IAC 2021 Congress Proceedings, 72nd International Astronautical Congress (IAC), Dubai, United Arab Emirates, 2021. [2] Giovanni Medici, Bart Van Hove, Rasmus Bergstrom, Laura Marti Ramos, Aerodynamic Vehicle Design, Flying Qualities, and Mission Analysis for a Reusable VTOL Micro-Launcher First Stage, IAC 2021 Congress Proceedings, 72nd International Astronautical Congress (IAC), Dubai, United Arab Emirates, 2021. [3] Daniel G. Kovacs, Sebastien Paris, Guillaume Grossir and Christophe F. Schram. An Experimental Approach to Determine the Aerodynamic Pitch Damping Coefficient of Slender Bodies in the Transonic Regime, AIAA 2020-3105. AIAA AVIATION 2020 FORUM. June 2020.