Studies and vorticity effects by the Euler equations with emphasis on supersonic flow fields

The primary purpose of the present report is to demonstrate how well the Euler equations in a supersonic marching program (SWINT) can predict the flow fields of bodies, wings, and wing-body combinations. The motivation was to see if if the Euler equations will predict the fin loads in highly vortical flow fields for cruciform missiles. Body-alone and wing-body flow fields were measured in the Bumblebee Program at a position where a tail might be placed. Those data, compared with the predictions of the Euler code, showed problems in both data and predictions. The data sometimes exhibited lack of repeatability which prevented critical comparison of data and theory in many instances. Also the lack of a sufficient number of nodes in the reverse flow regions of the flow made it difficult to get good predictions in this area. Some improvements were obtained by clustering. Computer studies of the flow field behind the wing showed that wing thickness effects had only a small effect on the calculated flow field. Also, imposition of a Kutta condition at the wing side edge had a small effect on the calculated flow field.