Variable Fidelity Studies in Wake Vortex Evolution, Safety, and Control

<p>The purpose of this research is to develop a variable-fidelity approach for addressing the safety of unmanned aerial system (UAS) operations in the national aerospace system (NAS). This task is implemented on the basis of safety investigation toolkit for analysis and reporting wake vortex safety system (SITAR WVSS) code, which is a dynamic low-fidelity model addressing generation, evolution, and interaction of the leader-aircraft wake vortex with the follower-aircraft lifting surfaces.</p> <p>The first part of the dissertation deals with the generation, evolution, and interaction of the wake vortices produced by an aircraft. In particular, it presents the results of the vortex safety analysis conducted for selected UAS operating alongside commercial aircraft in the terminal zone. The work further investigates and compares decay and transport of the wake vortex in the vicinity of various grounds including a solid surface, a forest canopy, and a water surface, representative of various terminal zone environments. The obtained high-fidelity results form the basis for reduced-order models to be integrated into the fast-analysis code under development for in-situ wake vortex safety predictions. The second part of the dissertation introduces a robust nonlinear control method that is proven to achieve altitude regulation in the presence of unmodeled external disturbances (e.g. wind gust, wake vortex disturbance) and actuator parametric uncertainty. This method is designed as a part of “Interaction” sub-module of the SITAR WVSS model. The results demonstrate the capability of the proposed nonlinear controller to asymptotically reject wind gust/wake-vortex disturbances and the parametric uncertainty. The proposed controller is a great choice for small UAV applications with limited computational resources.</p>

Name thesis:degree_name

Doctor of Philosophy in Aerospace Engineering

Level thesis:degree_level

Dissertation - Open Access

Discipline thesis:degree_discipline

Aerospace Engineering

Year

2018

Author dc:creator

• Kazarin, Petr

• variable fidelity
• wake vortex
• Aerospace Engineering
• Space Vehicles

Repository record dc:identifier

https://commons.erau.edu/edt/429

OAI identifier oai:identifier

oai:commons.erau.edu:edt-1428