Simplified Solution of the Compressible Lifting Surface Problem

Purvis, James W.; Burkhalter, John E.

doi:10.2514/3.51116

Cited by 8 publications

(6 citation statements)

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“…A further note regarding compressibility can be made at this point. The application of the Biot-Savart law for velocity induction, although formulated for incompressible flows, can be modified with the addition of the compressibility correction factor 24 and is used in the current approach to simulate higher Mach number flows. The importance of such corrections is made clear in Section-8 of this document.…”

Section: Solver Philosophymentioning

confidence: 99%

Aerodynamic Loads over Arbitrary Bodies by Method of Integrated Circulation

Ahuja

Hartfield

2016

Journal of Aircraft

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A method for the application of vorticity based potential-flow solvers to unstructured surface meshes has been created. This method is designed to maintain the advantages of the vorticity based solvers while removing the limitations of geometrical inputs associated with the philosophical approach. A discussion on the necessity and advantages of this approach has been presented. A modification to the evaluation of skinfriction coefficients using surface vorticity has also been developed. An unstructured wake-strand model has been developed to allow handling of wakes emanating from unstructured meshes. An attempt has been made to extend potential-flow solvers to the current industry surface meshing and numerical solver standards. This automated pipeline is considered to be robust enough to allow integration with optimizers unrestricted in their geometrical design spaces. A test-suite of basic shapes and bodies was tested to evaluate the fidelity of the new approach. An advanced test-suite was developed to stress-test the solver as well as to test out the geometry handling pipeline required to handle these test cases. It was determined that the solver is able to provide high fidelity results for a wide variety of test cases and is able to: work with conformal and non-conformal geometry interfaces, resolve surface intersections, work with both structured and unstructured meshes, work with both thick and thin bodies and work with manifold and non-manifold surface interfaces. iii ACKNOWLEDGMENTS The author would like to thank Dr. Roy Hartfield for providing the encouragement, support and a free-thinking environment for conducting this research. Thanks are also due to Dr. John Burkhalter and Dr. Andrew Shelton for helping develop the fundamental theories used in this work and to Dr. Mark Carpenter for providing an objective overview of the work as an external reader of this document. Thanks are also due to my mother, Dr. Sulekha Ahuja, for providing that metaphorical wall of support to rest on during these past few wonderful years of work.

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Section: Solver Philosophymentioning

confidence: 99%

Aerodynamic Loads over Arbitrary Bodies by Method of Integrated Circulation

Ahuja

Hartfield

2016

Journal of Aircraft

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“…Vector L is obtained by resolving the lifting surface theory using the kernel method [11], so that the aerodynamic load can be expressed by the formula…”

Section: Wing Modelmentioning

confidence: 99%

Multiobjective wing design using genetic algorithms and fuzzy logic

Saggiani

Caligiana

Persiani

2004

Proceedings of the Institution of Mechanical Engineers, Part G:

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The designer frequently faces problems in which the project depends on many parameters and the final solution must be evaluated according to several optimization objectives. This may be the case for the aeroelastic and aeromechanical design of lifting surfaces. The aim of the present paper is to show how the combined techniques of genetic algorithms (GAs) and fuzzy logic can be useful in these situations. The leading idea is the development of a tool to assist the designer in the preliminary phase of activity by assigning a genetic code to every possible solution and assessing its performance by means of a fuzzy controller in order to handle simultaneously different design criteria. Examples are given for some typical problems in aeronautical design.

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“…(11) and (13) for the total lift and moment is performed analytically in closed form. 12 However, because of the discontinuity resulting from the addition of an elevon, these equations must be integrated numerically when a gap exists or the elevon is deflected.…”

Section: Total Aerodynamic Forces and Momentsmentioning

confidence: 99%

“…Lifting surface theory is employed, with the solution following the procedure established by Purvis 12 and Burkhalter and Purvis. 13 The loading function over the multiple lifting surface is defined, and the Kernel function is then integrated over the surface.…”

Section: Introductionmentioning

confidence: 99%

“…(12) lift force on the wing freestream Mach number freestream dynamic pressure wing-elevon planform area (excluding gap area), reference area nondimensional perturbation velocity parallel to z axis Cartesian coordinates angle of attack Mach flow parameter, Vl -M 2 * elevon angle relative to wing (trailing edge down is positive) gap width between wing trailing edge and elevon leading edge wing leading-edge sweep angle nondimensional spanwise variable nondimensional variables, see Eq. ( …”

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confidence: 99%

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Load Distribution on Multielement Deformed Airfoils with Gap Effects

Abernathy

Burkhalter

1982

Journal of Aircraft

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x,y, z a. A 6The aerodynamic loading for deformed wings with elevens in subsonic flow is considered. The solution procedure falls into the potential flow category with appropriate restrictions. Lifting surface Kernel function formulation is used in which the local pressure loading for both wing and elevon is determined simultaneously and written as a summation equation. The solution procedure allows closed-form results to be obtained for the elevon hinge moments. Cases under study include gaps between wing and elevon in addition to arbitrary wingelevon deformations. Fuselage effects and leading-edge suction are also used to apply results to a general configuration. Results for all cases compare very well with experimental data. Experimental data taken in a lowspeed wind tunnel are presented for a cropped delta wing and rectangular elevon in which the wing-elevon gap was the primary test variable.

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Simplified Solution of the Compressible Lifting Surface Problem

Cited by 8 publications

References 10 publications

Aerodynamic Loads over Arbitrary Bodies by Method of Integrated Circulation

Aerodynamic Loads over Arbitrary Bodies by Method of Integrated Circulation

Multiobjective wing design using genetic algorithms and fuzzy logic

Load Distribution on Multielement Deformed Airfoils with Gap Effects

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