Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Entire DC Network
Aerodynamic Centers Of Arbitrary Airfoils Below Stall, Douglas F. Hunsaker, Orrin D. Pope, Jeffrey D. Taylor, Josh Hodson
Aerodynamic Centers Of Arbitrary Airfoils Below Stall, Douglas F. Hunsaker, Orrin D. Pope, Jeffrey D. Taylor, Josh Hodson
Mechanical and Aerospace Engineering Student Publications and Presentations
The aerodynamic center of an airfoil is commonly estimated to lie at the quarter-chord. This traditional estimate is based on thin airfoil theory, which neglects aerodynamic and geometric nonlinearities. Even below stall, these nonlinearities can have a significant effect on the location of the aerodynamic center. Here, a method is presented for accurately predicting the aerodynamic center of any airfoil from known lift, drag, and pitching-moment data as a function of angle of attack. The method accounts for aerodynamic and geometric nonlinearities, and it does not include small-angle, small-camber, and thin-airfoil approximations. It is shown that the aerodynamic center of …
Minimizing Induced Drag With Weight Distribution, Lift Distribution, Wingspan, And Wing-Structure Weight, Warren F. Phillips, Douglas F. Hunsaker, Jeffrey D. Taylor
Minimizing Induced Drag With Weight Distribution, Lift Distribution, Wingspan, And Wing-Structure Weight, Warren F. Phillips, Douglas F. Hunsaker, Jeffrey D. Taylor
Mechanical and Aerospace Engineering Student Publications and Presentations
Because the wing-structure weight required to support the critical wing section bending moments is a function of wingspan, net weight, weight distribution, and lift distribution, there exists an optimum wingspan and wing-structure weight are presented for rectangular wings with four different sets of design constraints. These design constraints are fixed lift distribution and net weight combined with 1) fixed maximum stress and wing loading, 2) fixed maximum deflection and wing loading, 3) fixed maximum stress and stall speed and 4) fixed maximum deflection and stall speed. For each of these analytic solutions, the optimum wing-structure weight is found to depend …
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 …
A Sine-Summation Algorithm For The Prediction Of Ship Deck Motion, Christian R. Bolander, Douglas F. Hunsaker
A Sine-Summation Algorithm For The Prediction Of Ship Deck Motion, Christian R. Bolander, Douglas F. Hunsaker
Mechanical and Aerospace Engineering Student Publications and Presentations
Landing a fixed-wing aircraft on a moving aircraft carrier is a risky and inefficient process. Having an accurate prediction of ship deck motion decreases the risk posed to both the pilot and the aircraft and increases the efficiency of landing maneuvers. The present work proposes the use of a sine-summation algorithm to predict future ship motion. The algorithm decomposes recorded ship acceleration data into its characteristic harmonic parameters using a fast Fourier transform. The harmonic parameters are then used in a summation of sine waves to create a fit for the acceleration data, which is projected into future time intervals …
A Procedure For The Calculation Of The Perceived Loudness Of Sonic Booms, Christian R. Bolander, Douglas F. Hunsaker, Hao Shen, Forrest L. Carpenter
A Procedure For The Calculation Of The Perceived Loudness Of Sonic Booms, Christian R. Bolander, Douglas F. Hunsaker, Hao Shen, Forrest L. Carpenter
Mechanical and Aerospace Engineering Student Publications and Presentations
Implementing a method to calculate the human ear’s perceived loudness of a sonic boom requires consulting scattered literature with varying amounts of detail. This work describes a comprehensive implementation of Stevens’ Mark VII in Python, called PyLdB. References to literary works are included in enough detail so that the reader could use this work as a guide to implement the Mark VII algorithm. The details behind the mathematics of the Mark VII algorithm are included and PyLdB is used to calculate the perceived loudness of an example pressure signature. PyLdB is benchmarked against a widely used and validated code by …