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Full-Text Articles in Engineering
Constrained Hermite Tls For Mesh-Free Derivative Estimation Near And On Boundaries, Robert A. Mcdonald, Alejandro Ramos
Constrained Hermite Tls For Mesh-Free Derivative Estimation Near And On Boundaries, Robert A. Mcdonald, Alejandro Ramos
Aerospace Engineering
A Taylor series least-squares approach to estimating derivatives on scattered data is extended to include derivative observation or specification. This approach allows improved estimation of derivatives near boundaries as compared with the standard ghost node approach. It also enables a unique method of estimating derivatives in a surface using only surface data.
Considerations For Numerical Modeling Of Inverted Wings In Ground Effects, Graham Doig, Tracie J. Barber
Considerations For Numerical Modeling Of Inverted Wings In Ground Effects, Graham Doig, Tracie J. Barber
Aerospace Engineering
No abstract provided.
Mission Performance Considered As Point Performance In Aircraft Design, Robert A. Mcdonald
Mission Performance Considered As Point Performance In Aircraft Design, Robert A. Mcdonald
Aerospace Engineering
The cruise or loiter performance of an aircraft is intimately tied to its wing loading and its thrust-to-weight ratio. Paradoxically, mission performance is often not considered when these fundamental aircraft parameters are determined in conceptual design. In this paper, the traditional constraint diagram is extended to include contours of range or endurance parameter. These performance metrics represent the mission-performance capability of the aircraft without sizing the aircraft to a particular mission. This gives the designer an immediate and intuitive understanding of the tradeoff between the point and mission performance of the aircraft. The potential freedom for the designer to choose …
Part 1: The Wind Tunnel Model Design And Fabrication Of Cal Poly's Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina K. Jameson, David D. Marshall, Rory Golden, Eric Paciano, Robert J. Englar, Richard J. Gaeta, Jay Paterson, Dave Mason
Part 1: The Wind Tunnel Model Design And Fabrication Of Cal Poly's Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina K. Jameson, David D. Marshall, Rory Golden, Eric Paciano, Robert J. Englar, Richard J. Gaeta, Jay Paterson, Dave Mason
Aerospace Engineering
A collaboration between California Polytechnic Corporation with Georgia Tech Research Institute (GTRI) and DHC Engineering worked on a NASA NRA to develop predictive capabilities for the design and performance of Cruise Efficient, Short Take-Off and Landing (CESTOL) subsonic aircraft. In addition, a large scale wind tunnel effort to validate these predictive capabilities for this NRA for aerodynamic and acoustic performance during takeoff and landing has been undertaken. The model, Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA), was designed as a 100 passenger, N+2 generation, regional, cruise efficient short takeoff and land (CESTOL) airliner with hybrid blended wing-body with …
Improved Meshing Technique For The Engine Exhaust Of An Over-The-Wing Engine And Circulation Control Wing Configuration, John Pham, David D. Marshall
Improved Meshing Technique For The Engine Exhaust Of An Over-The-Wing Engine And Circulation Control Wing Configuration, John Pham, David D. Marshall
Aerospace Engineering
This paper details the results of ongoing efforts to improve upon the meshing techniques required to produce accurate RANS CFD solutions for attached and separated flows for a Circulation Control aircraft. Work, thus far, under the current NASA Research Announcement (NRA) project has revolved around an unstructured near-body volume mesh due to its robustness for complicated geometries. However, it has been found that this technique does a poor job capturing detailed flow features such as the boundary layer, shear layer, and wake of large velocity-gradient regions. Its hindrance is primarily due to the limitations of current computational resources, thus new …
A Scientific Software Verification Library Based On The Method Of Manufactured Solutions, David D. Marshall
A Scientific Software Verification Library Based On The Method Of Manufactured Solutions, David D. Marshall
Aerospace Engineering
A software library, avali, is being developed in the C++ programming language that applies the Method of Manufactured Solutions (MMS) to a variety of partial differential equation (PDE) problems. This library will allow researchers to utilize MMS as a software verification process without developing significant amounts of testing code. The library is split into 3 components: solution classes which can be used as manufactured solutions to PDE problems; PDE problem classes which represent specific types of PDEs to be solved (such as linear convection-diffusion equation or Poisson's equation); and post-processing classes that collect the convergence information and can perform various …
Part 2: Preparation For Wind Tunnel Model Testing And Verification Of Cal Poly’S Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina Jameson, David D. Marshall, Robert Ehrmann, Eric Paciano, Robert J. Englar, William C. Horne
Part 2: Preparation For Wind Tunnel Model Testing And Verification Of Cal Poly’S Amelia 10 Foot Span Hybrid Wing-Body Low Noise Cestol Aircraft, Kristina Jameson, David D. Marshall, Robert Ehrmann, Eric Paciano, Robert J. Englar, William C. Horne
Aerospace Engineering
A collaboration between California Polytechnic Corporation with Georgia Tech Research Institute (GTRI) and DHC Engineering worked on a NASA NRA to develop predictive capabilities for the design and performance of Cruise Efficient, Short Take-Off and Landing (CESTOL) subsonic aircraft. The focus of this work presented in this paper gives details of a large scale wind tunnel effort to validate predictive capabilities for this NRA for aerodynamic and acoustic performance during takeoff and landing. The model, Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA), was designed as a 100 passenger, N+2 generation, regional, cruise efficient short takeoff and land (CESTOL) …
Investigation Of The Unsteady Behavior Of A Circulation Control Wing Using Computational Fluid Dynamics, Jonathon A. Lichtwardt, David D. Marshall
Investigation Of The Unsteady Behavior Of A Circulation Control Wing Using Computational Fluid Dynamics, Jonathon A. Lichtwardt, David D. Marshall
Aerospace Engineering
This paper details the results of an investigation into the unsteady behavior of a circulation control wing using computational fluid dynamics. Oscillations in the lift coefficient of up to 10% are observed for steady state simulations. An investigation into the source of the unsteadiness is underway, and the results to date are presented. It is shown that the periodic oscillations are independent of the above the wing mounted engine effects on the cruise efficient short take-off and landing aircraft. The oscillations are also a viscous phenomenon that does not dampen as the solution marches through steady state. It is proposed …
A Meshless Finite Difference Scheme For Compressible Potential Flows, Alejandro Ramos, Robert A. Mcdonald
A Meshless Finite Difference Scheme For Compressible Potential Flows, Alejandro Ramos, Robert A. Mcdonald
Aerospace Engineering
A meshless solution algorithm for the full potential equation has been developed by applying the principles of the Taylor Least Squares (TLS) method. This method allows for a PDE to be discretized on a local cloud of scattered nodes without the need of connectivity data. The process for discretizing the full potential equation within a meshless framework is outlined along with a novel Hermite TLS technique for enforcement of Neumann boundary conditions. Several two-dimensional test cases were solved that compare well with analytical and benchmark solutions. The first test case solved for the subcritical compressible flow over a circular cylinder …