Tipo di tesi
Tesi di laurea magistrale
Titolo
Static and dynamic analysis of the aerodynamic stability and trajectory simulation of a student sounding rocket.
Dipartimento
INGEGNERIA CIVILE E INDUSTRIALE
Corso di studi
INGEGNERIA AEROSPAZIALE
Data inizio appello
28/04/2015
Riassunto (Italiano)
Scope of this thesis is the analysis and validation of the aerodynamics of the SMART rocket from the point of view of both the aerodynamic stability and trajectory. The rocket summarizes the contribution of the Technical University (Technische Universitat) Dresden to the STudentische Experimental-RaketeN (STERN) program, promoted by the German Space Administration (DLR). In the first part of this work, all the possible disturbances commonly affecting the rocket during its atmospheric flight are modeled in an analytical fashion. These include thrust vector misalignments and offsets, combustion instabilities, fins misalignments and presence of wind. Then these perturbing terms are considered inside properly defined models able to provide the response of the vehicle in terms of the time evolution of its vertical axis deflection with respect to the velocity direction, i.e. the time profile of the angle of attack. In this way the aerodynamic stability of the any uncontrolled rocket could be possibly studied from both the static and dynamic point of view. The previous models are applied to the actual state of the SMART rocket and the most critical types of disturbance are identified with the related safety margins. Subsequently a design procedure is developed to define a new aerodynamics able to extend the most critical of the previous margins. This procedure is based on the study of the most important quantities related to the aerodynamic stability problem as a function of a properly defined set of geometrical parameters. These parameters are directly related with the aerodynamic shape of the rocket fins. The optimum which results in the best compromize between the vehicle response to all the previous disturbances is so evaluated and considered in the subsequent trajectory validation. This is realized by means of the ASTOS software, a powerful mission and system analysis and optimization program funded by the European Space Research and Technology Center (ESA/ESTEC). This program has been used both to verify the previous analytical response regarding the vehicle aerodynamic stability and to validate the trajectory of the updated configuration of the SMART rocket. Both 3 dof and 6 dof vertical and non-vertical analysis with and without perturbations have been simulated. The results are compared with those provided by dedicated analytical models whenever is possible. In conclusion the updated configuration obtained from the analytical design results to be the optimum one able to satisfy the imposed requirements in terms of minimum altitudes and maximum culmination velocities with any type of disturbance.
