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Full-Text Articles in Engineering
High Resolution Simulation Of Full Aircraft Control At Flight Reynolds Numbers, Scott A. Morton, James R. Forsythe, David R. Mcdaniel, Keith Bergeron, Russell M. Cummings, Stefan Goertz, Jurgen Seidel, Kyle D. Squires
High Resolution Simulation Of Full Aircraft Control At Flight Reynolds Numbers, Scott A. Morton, James R. Forsythe, David R. Mcdaniel, Keith Bergeron, Russell M. Cummings, Stefan Goertz, Jurgen Seidel, Kyle D. Squires
Aerospace Engineering
This paper documents interim results of a three year project to develop a computational method for accurately determining static and dynamic stability and control characteristics of fighter and transport aircraft with various store configurations, as well as the aircraft response to pilot input. In this second year of the project computational data is gathered for a rigid F-16C with no control surface movement in forced motion that approximates flight test maneuvers. "Computational maneuvers" designed to efficiently gather three axes of motion data to build a comprehensive reduced order model are also developed. The data is then post- processed to determine …
The Onset For Compressibility Effects For Aerofoils In Ground Effect, G. Doig, T.J. Barber, E. Leonardi, A.J. Neely
The Onset For Compressibility Effects For Aerofoils In Ground Effect, G. Doig, T.J. Barber, E. Leonardi, A.J. Neely
Aerospace Engineering
The influence of flow compressibility on a highly-cambered inverted aerofoil in ground effect is presented, based on two-dimensional computational studies. This type of problem has relevance to open-wheel racing cars, where local regions of high-speed subsonic flow form under favourable pressure gradients, even though the maximum freestream Mach number is typically considerably less than Mach 0.3. An important consideration for CFD users in the field is addressed in this paper, the freestream Mach number at which flow compressibility significantly affects aerodynamic performance. More broadly, for aerodynamicists, the consequences of this are also considered. Comparisons between incompressible and compressible CFD siulations …
F- 16xl Unsteady Simulations For The Cawapi Facet Of Rto Task Group Avt- 113, Scott A. Morton, David R. Mcdaniel, Russell M. Cummings
F- 16xl Unsteady Simulations For The Cawapi Facet Of Rto Task Group Avt- 113, Scott A. Morton, David R. Mcdaniel, Russell M. Cummings
Aerospace Engineering
This work represents the USAF Academy portion of a culmination of three years of cooperative research in the Cranked Arrow Wing Aerodynamics International (CAWAPI) RTO Task Group, AVT-113. The objective of the group was to compute high resolution CFD simulations of a subset of the conditions created in the CAWAP flight test program managed by NASA Langley researchers and others. Seven flight conditions were chosen with four of them at symmetric conditions of medium to high angle of attack and subsonic Mach numbers, one symmetric condition at a transonic low angle of attack condition, and two conditions at medium angle …
The Happy Accidents Of Teaching Aircraft Design, David W. Hall, Russell M. Cummings
The Happy Accidents Of Teaching Aircraft Design, David W. Hall, Russell M. Cummings
Aerospace Engineering
The aircraft design curriculum at Cal Poly has grown and evolved over the past decades to include a full year of senior aircraft design and an introductory aircraft design course in the sophomore year. The combination of sophomore and senior aircraft design courses has created the circumstance where a “cult” of aircraft design has developed. The curriculum is producing students who are enthusiastic and motivated education, as well as being competent designers after they graduate. A number of “happy accidents” has led to this fortunate situation, including: allowing the sophomores to perform a full aircraft design, having the sophomores work …
Comparison Of Des And Urans For Unsteady Vortical Flows Over Delta Wings, L. A. Shiavetta, K. J. Badcock, Russell M. Cummings
Comparison Of Des And Urans For Unsteady Vortical Flows Over Delta Wings, L. A. Shiavetta, K. J. Badcock, Russell M. Cummings
Aerospace Engineering
The unsteady behaviour of delta wing vortical flows is still a subject which is a challenge for numerical methods, such as computational fluid dynamics. New approaches to turbulence modelling, such as detached eddy simulation (DES) have been proposed which allow for greater accuracy of the numerical predictions. However, this increase in accuracy comes with a considerable increase in computational expense compared to traditional turbulence modelling. This investigation considers the use of both DES and unsteady Reynolds averaged Navier-Stokes (URANS) turbulence methods in the prediction of unsteady vortical flows. Calculations using DES are initially considered for two test cases and the …
Circulation Control And Its Application To Extreme Short Take-Off And Landing Vehicles, Julianna B. De La Montanya, David D. Marshall
Circulation Control And Its Application To Extreme Short Take-Off And Landing Vehicles, Julianna B. De La Montanya, David D. Marshall
Aerospace Engineering
Circulation Control is a high-lift method discovered in 1935 when Henry Coanda accidentally stumbled upon the technology. Research was conducted in the 1970‘s and 1980‘s to develop this technique, but the idea fell out of vogue until recently. Energy is introduced into the flow field by means of a jet ejected tangentially from a slot located near the trailing edge of the airfoil; thus changing the effective chamber of the airfoil and increasing lift. Extreme Short Take-Off and Landing (ESTOL) vehicles can use this technology to alleviate today‘s congested airports by reutilizing the small runways that are currently unexploited due …
Wing-Nacelle Assembly Multidisciplinary Performance Optimization, Yevgeniy M. Gisin, David D. Marshall
Wing-Nacelle Assembly Multidisciplinary Performance Optimization, Yevgeniy M. Gisin, David D. Marshall
Aerospace Engineering
The paper analyzes the aerodynamics benefits of above-wing mounting of turbofan engines and performs a trade-off study of the structural limitations with this mounting method. This research is based on the US Patent #6,308,913, aiming to quantify the actual benefit derived from the drag reduction measure described in the patent. The paper focuses on the analysis of a turbofan engine, which when installed above an aircraft’s wing creates a flow field optimized to reduce the overall drag experienced by the wing nacelle assembly. This installation is designed to reduce wave drag during transonic cruise and therefore the wing-nacelle geometry was …
The Role Of Error In The Conceptual Design Of A Transport Aircraft, Robert A. Mcdonald
The Role Of Error In The Conceptual Design Of A Transport Aircraft, Robert A. Mcdonald
Aerospace Engineering
A fidelity trade environment was demonstrated by using it to simulate a decision making process for a transport aircraft. This scenario was not possible without the fidelity trade environment. The role of system feedback and coupling in error stability was also investigated.
A sensitivity approach which relies on the system sensitivity matrix was used to rapidly approximate the propagation of error through the complex system. In verification tests, the sensitivity approach provided approximate results substantially similar to a Monte Carlo approach that was many orders of magnitude more expensive. The rapid sensitivity approach to modeling error propagation enabled the responsive …