Delta Wing

Steady-state Euler simulation of a half-span delta wing at an angle of attack of 20 degrees and a Mach number of 0.2.

The first picture on the left shows the interaction between the leading-edge vortex and a vortex formed by the roll-up of the vortex sheet shed from the trailing-edge. The visualization is done by an isosurface of total pressure. In the picture on the right, the vortices are highlighted by streamlines released at the apex and the trailing-edge of the wing. The wing is colored by the pressure coefficient and the low pressure region below the vortex is visible. The streamlines are colored by the longitudinal component of the velocity. It shows the high velocity present in the core of the vortex at the apex and the region of low speed past the trailing-edge.

This study of the wake roll-up behind a delta wing has been performed on a refined computational grid. The initial mesh was fine in the wake region and automatic mesh refinement has been applied to it to improve the quality of the predictions. The figure below shows the tetrahedra created by the first refinement step (in red), using the h-refinement technique and a sensor to capture the vortex in the flow field. The final grid has 7.5M tetrahedra from around 1 million in the initial mesh.

Yann Le Moigne, KTH, April 2004.