Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication
- Publication Type
Articles 1 - 4 of 4
Full-Text Articles in Mechanical Engineering
Sensitivity And Estimation Of Flying-Wing Aerodynamic, Propulsion, And Inertial Parameters Using Simulation, Jaden Thurgood, Douglas F. Hunsaker
Sensitivity And Estimation Of Flying-Wing Aerodynamic, Propulsion, And Inertial Parameters Using Simulation, Jaden Thurgood, Douglas F. Hunsaker
Mechanical and Aerospace Engineering Student Publications and Presentations
This paper explores the difficulties of aircraft system identification, specifically parameter estimation, for a rudderless aircraft. A white box method is used in conjunction with a nonlinear six degree-of-freedom aerodynamic model for the equations of motion in order to estimate 33 parameters that govern the aerodynamic, inertial, and propulsion forces within the mathematical model. The analysis is conducted in the time-domain of system identification. Additionally, all the parameters are estimated using a single flight rather than a series of shorter flights dedicated to estimating specific sets of parameters as is typically done. A final flight plan is developed with a …
Discrete Vortex Modeling Of Aerodynamic Flutter Of A Flat Plate With Damped Oscillations, Emma Chao
Discrete Vortex Modeling Of Aerodynamic Flutter Of A Flat Plate With Damped Oscillations, Emma Chao
UNLV Theses, Dissertations, Professional Papers, and Capstones
Aerodynamic flutter is the unstable oscillation of a body caused by the interaction of aerodynamic forces, structural elasticity, and inertial effects induced by vortex shedding. Current models of this phenomenon require finite element analysis and extensive computational power and processing time. The purpose of this study was to develop and validate a program that is faster and more efficient than existing approaches by using the discrete vortex method (DVM). By reducing the complexities of flutter to the shedding of vortices in an inviscid model of a two-dimensional flat plate with a torsional spring constant at its center, this phenomenon can …
A Multi-Fidelity Prediction Of Aerodynamic And Sonic Boom Characteristics Of The Jaxa Wing Body, Forrest L. Carpenter, Paul G. A. Cizmas, Christian R. Bolander, Ted N. Giblette, Doug F. Hunsaker
A Multi-Fidelity Prediction Of Aerodynamic And Sonic Boom Characteristics Of The Jaxa Wing Body, Forrest L. Carpenter, Paul G. A. Cizmas, Christian R. Bolander, Ted N. Giblette, Doug F. Hunsaker
Mechanical and Aerospace Engineering Student Publications and Presentations
This paper presents a detailed comparison between the linear panel solver PANAIR A502 and the in-house Navier–Stokes solver UNS3D for a supersonic low-boom geometry. The high-fidelity flow solver was used to predict both the inviscid and laminar flow about the aircraft geometry. The JAXA wing body was selected as the supersonic low-boom geometry for this study. A comparison of the undertrack near-field pressure signatures showed good agreement between the three levels of model fidelity along the first 0.8L of the signature. Large oscillations in the PANAIR results were observed. The PANAIR discrepancies were traced back to violations of the …
Three-Dimensional Aerodynamic Shape Optimization Using Discrete Sensitivity Analysis, Gregory Wayne Burgreen
Three-Dimensional Aerodynamic Shape Optimization Using Discrete Sensitivity Analysis, Gregory Wayne Burgreen
Mechanical & Aerospace Engineering Theses & Dissertations
An aerodynamic shape optimization procedure based on discrete sensitivity analysis is extended to treat three-dimensional geometries. The function of sensitivity analysis is to directly couple computational fluid dynamics (CFD) with numerical optimization techniques, which facilitates the construction of efficient direct-design methods. The development of a practical three-dimensional design procedures entails many challenges, such as: (1) the demand for significant efficiency improvements over current design methods; (2) a general and flexible three-dimensional surface representation; and (3) the efficient solution of very large systems of linear algebraic equations. It is demonstrated that each of these challenges is overcome by: (1) employing fully …