Interactive Grid Generation Research Articles

2307 GUIを用いた対話型格子形成システムの構築(OS23-2.次世代CAD/CAM/CAE/CG/CSCW/CAT/C-Control(2),OS・一般セッション講演)

2307 GUIを用いた対話型格子形成システムの構築(OS23-2.次世代CAD/CAM/CAE/CG/CSCW/CAT/C-Control(2),OS・一般セッション講演)

Interactive grid generation and NURBS applications

This paper addresses recent developments of grid generation techniques employing nonuniform rational B-spline formulations (NURBS). Grid refinement algorithms for arbitrary curves and surfaces with NURBS maintain high fidelity of the geometry, and allow time-efficient interactive grid generation. Bezier curve formulations are utilized to subdivide surface patches to accomplish a smooth and near orthogonal zonal grid. A CAD/Grid interface code based on NURBS formulations has been developed which converts CAD data from IGES files into the format accepted by the structured grid system. Two interactive grid generation codes, a general-purpose code and a customized one for turbomachinery configurations, have been developed on the basis of NURBS' definition.

Vortex flow control using fillets on a double-delta wing

This article presents results from a subsonic numerical investigation on the effects of geometry modifications at the junction of the leading edge extension (LEX) and wing of a flat-plate cropped double-delta wing at moderate to high angles of attack. The baseline planform of the double-delta wing configuration consisted of a strake with a 76-deg leading-edge sweep and a wing with a 40-deg leading-edge sweep with sharp, beveled leading edges. The geometry modifications included various fillet shapes with planform areas equal to 1% of the baseline wing reference area. A hyperbolic grid generation method was developed and used in conjunction with an existing interactive grid generation system to create high quality C-O type multiblock grids about the configurations studied. The Euler and Reynolds averaged Navier-Stokes (RANS) equations were solved numerically using two finite-volume production flow solvers. The baseline configuration numerical results correlated well with existing published experimental data. Grid refinement using the RANS revealed vortex sheet tearing on the wing. Fillets enhanced the lift by 14% at low angle of attack, and 18% at high angle of attack with a slight improvement in lift-to-drag ratio. The fillets may be good candidates for roll control devices.

Interactive grid generation with control points

Abstract The control point form of algebraic grid generation is developed in a rigorous manner to elucidate the key attributes of the mathematical theory and is demonstrated graphically to visualize the type of action that is possible. Altogether, the algebraic coordinate transformation represents a flexible structure that is adaptable to various situations. It presents the capability to effectively free-form model the boundaries of objects in a field about which a numerical simulation is to be performed with the generated grid.