Three-dimensional elliptic grid generation about fighter aircraft for zonal finite-difference computations

Abstract

An elliptic grid-generation method for finite-difference computations about complex aerodynamic configurations is developed. A zonal approach is used, which involves first making a coarse global grid filling the entire physical domain and then subdividing regions of that grid to make the individual zonal grids. The details of the grid-generation method are presented along with results of the present application, a wingbody configuration based on the F-16 fighter aircraft.

Open-Water Thrust and Torque Predictions of a Ducted Propeller System with a Panel Method

“…where ω R is the mean relative flow velocity through the gap and ΔC p is the pressure difference at the blade tip in terms of the pressure coefficient defined by (11). To incorporate this expression for the mean velocity into the Panel Method, an additional strip of panels along the blade tip is introduced which closes the gap.…”

“…Equidistant angular spacing is used in circumferential direction. For the discretisation of the hub surface, an elliptical grid generator is used [11]. The blade and duct wake surfaces are discretised in the spanwise and circumferential directions, extending downstream from the trailing edge the corresponding strips on the propeller blade and duct surfaces.…”

Transient natural convection heat transfer of fluids with variable viscosity between concentric and vertically eccentric spheres

“…When the modified Sorenson's method [17] is used to generate the grid line, it can get the grid system with orthogonality along all boundaries and this system can enhance the accuracy of calculation. Besides, the hyperbolic tangent distribution [18] is applied to have a denser grid distribution near the boundaries.…”

Two Modified Versions of Hsu-Lee's Elliptic Solver of Grid Generation

“…Their scheme reveals that Thomas and Middlecoffs formulation (for interior points near boundaries) does not completely reflect the curvature effect of the boundary [7, 81. Sorenson [9] had improved the Steger and Sorenson method so that all the boundaries can preserve orthogonality and had great success. However, his modification is not perfect, because the expression of control functions is not in the form of interpolation.…”

“…First, a methodology combining Sorenson's [9] and Hsu and Lee's [lo] extensions, which controls the grid around all of the boundaries, is proposed. Second, a procedure (similar to the Steger and Sorenson or Hsu and Lee method) is developed that not only ensures grid control in the region between two opposite boundaries, but also stretches the grid along the grid lines connecting them.…”