Showing papers on "Vortex lattice method published in 1982"
01 Aug 1982
TL;DR: In this article, an unsteady vortex lattice method is presented for the calculation of the aerodynamic forces acting on lifting surfaces undergoing complex three dimensional motion of a slender delta wing.
Abstract: An unsteady vortex lattice method is presented for the calculation of the aerodynamic forces acting on lifting surfaces undergoing complex three dimensional motion. For the present case the nonsymmetric motion of a slender delta wing was considered and the resulting lateral characteristics were calculated. The flow separation line was specified along the wing leading edge and the emanating vortex sheet shape and rollup was then calculated. Numerical results are presented for the combined high angle of attack and side slip condition and for the wing constant roll and coning motions.
17 citations
01 Jul 1982
TL;DR: In this article, the authors examined the feasibility of applying a vortex lattice method to propeller performance analysis, which allows the calculation of spanwise and chordwise pressure distributions on thin propeller blades of arbitrary planform.
Abstract: : The objective of this thesis is to examine the feasibility of applying a vortex lattice method to propeller performance analysis. This method allows the calculation of spanwise and chordwise pressure distributions on thin propeller blades of arbitrary planform. The research for this project involves the application of a vortex lattice method to a propeller with twisted, non- cambered, constant chord blades. The analysis assumes incompressible, inviscid flow over thin sections. The helical wake is modeled as a series of straight vortex filament segments. A computer code has been developed which uses a vortex lattice method to predict performance for propellers. Results are shown for several operating conditions, using various angle of attack distributions, numbers of blades on the propeller, and advance ratios. Similar results are shown using the blade-element theory for comparison. Results indicate that this vortex lattice method is applicable to initial propeller performance analysis.
4 citations
TL;DR: In this article, a new method was developed for solving the lifting surface equation for thin subsonic wings which can also be interpreted as a vortex lattice method, where the downwash equation was transformed into double integrals involving Cauchy-type singularities in the chordwise and spanwise directions.
Abstract: A new method is developed for solving the lifting-surface equation for thin subsonic wings which can also be interpreted as a vortex lattice method. The downwash equation is transformed into double integrals involving Cauchy-type singularities in the chordwise and spanwise directions. A technique developed by Lan for airfoil theory is used to reduce both integrals to a double summation. This method properly accounts for the leadingedge singularity, Cauchy singularity, and Kutta condition. The solutions generally compared well with other lifting-surface theories, but with much smaller computational times, and the method was found to be more accurate and converge faster than conventional vortex lattice methods. b c c
2 citations