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The next generation of Autonomous Underwater Vehicles (AUV) can impact our observation of the world. The flight simulation and full-envelope hydrodynamics modeling can improve the performance of AUVs in terms of control, navigation and positioning. In order to achieve agile maneuverability, a more accurate database of full-envelope hydrodynamic coefficients is supposed to be generated. Two semi-empirical methods, Jorgensen and DATCOM, and two numerical method, Computational Fluid Dynamics (CFD) and XFLR5 are used to push the boundaries of hydrodynamic coefficients: lift, drag and moment coefficients for flight-style AUVs at the Swedish Maritime Robotics Center (SMaRC). A comparison of different approaches and tools, and an analysis of the most appropriate approaches for different regions of a defined maneuver has been conducted in this thesis. A data confidence level was proposed as a way to estimate the accuracy of the data and a structured database was built in terms of data confidence level. Different components of the AUV such as the hull body and wings were analyzed separately. The new database is input to a 3DOF Simulink model and the 6DOF SMaRC hydrobatics simulator for flight dynamics simulations. Simulations show that the new database has a good applicability.

This report focuses on the utilisation of flight mechanics in the context of aircraftconceptual design to assess stability, control, and motion characteristics. The pri-mary objective is to acquire the equations of motion and implement longitudinalstability and control criteria using Pacelab Aircraft Preliminary Design 8.1, a com-mercial software tool. The equations and criteria employed in this study are derivedfrom an extensive review of relevant literature.By incorporating a dedicated Flight Mechanics chapter within the software, it be-comes possible to evaluate aircraft concepts under varying conditions. To ensureaccuracy and validity, DATCOM+ and OpenVSP were employed for testing andverification purposes.The key aspects covered in this report include flight mechanics, its implementationin Pacelab APD 8.1, determination of aerodynamic derivatives, formulation of equa-tions of motion, and their application to the B747 aircraft model. The emphasis liesin assessing longitudinal stability and control, including specific characteristics suchas the phugoid and short period modes.This report provides valuable insights into the integration of flight mechanics withinthe Pacelab APD 8.1 software for aircraft conceptual design. The results contributeto a better understanding of stability and control parameters and their impact onaircraft performance.

General aircraft dynamic stability theory was used to predict the natural frequencies, damping ratios and time constants of the dynamic modes for three specific small UAVs with wingspans on the scale from 0.6 meters to 1.2 meters. Using USAF DatCom methods, a spreadsheet program for predicting the dynamic stability and handling qualities of small UAVs was created for use in the design stage of new small UAV concept development. This program was verified by inputting data for a Cessna-182, and by then comparing the program output with that of a similar program developed by DAR Corporation. Predictions with acceptable errors were made for all of the dynamic modes except for the spiral mode. The design tool was also used to verify and develop dynamic stability and handling qualities design guidelines for small UAV designers. Using this design tool, it was observed that small UAVs tend to exhibit higher natural frequencies of oscillation for all of the dynamic modes. Comparing the program outputs with military handling qualities specifications, the small UAVs at standard configurations fell outside the range of acceptable handling qualities for short-period mode natural frequency, even though multiple test pilots rated the flying qualities as acceptable. Using dynamic scaling methods to adjust the current military standards for the short period mode, a new scale was proposed specifically for small UAVs. This scale was verified by conducting flight tests of three small UAVs at various configurations until poor handling qualities were observed. These transitions were observed to occur at approximately the boundary predicted by the new, adjusted scale.