title: DIAMOND WINGS IN SUPERSONIC FLOW WITH SLIP
Creators: name: MAKSIMOV, F.A.
name: OSTAPENKO, N.A.
name: ZUBIN, M.A.
Publisher: name: Proceedings of the 8th European Conference for Aeronautics and Space Sciences. Madrid, Spain, 1-4 july 2019
Year: 2019
Subjects: AERODYNAMICS
SUPERSONIC

description: The results of numerical and experimental studies of asymmetric flow around diamond wings on modes with attached shock waves or centered rarefaction waves on the leading edges with the Mach number M=3 are presented. The computation codes of second-order approximation were developed on special grids within the ideal gas model, which made it possible to obtain original data on asymmetric flow around diamond wings. A wide variety of flow patterns in the shock layer was found, depending on the Mach number, angles of attack and slip, due to presence of the break point of the transverse wing outline. In particular, disruption of flow from the windward console and presence of a vortex on the flow modes with slip and subsonic (transverse) flow in the vicinity of the central chord of the wing; the existence of trans- and supersonic flow along the vortex circumference and in the return flow near the wall of the lee console with the formation of shock waves with increasing slip angle were found. Approaching of the spreading point of streamlines, closing the vortex, and the node of streamlines on the lee console surface are typical for one of the sequences of flow patterns, occurring at the moderate Mach numbers of the undisturbed flow with increasing slip angle. When an outline of conditions is realized in the vicinity of the breakpoint that allow for the existence of a centered rarefaction wave, the vortex moves downstream along the wing surface, and a shock wave forms in front of it. After `merging\' of the indicated spreading point and node of streamlines on the leeward console, only the flowing down point remains, which includes streamlines from the front edges of the wing and Ferry vortex singularity above it. The existence of flow patterns with the formation of a vortex on the lee outer wing in the vicinity of the central chord was confirmed in the experiments with M=3 using various methods, in particular, a special shadow method for visualizing conical flows. The results of a numerical study of the possibility of controlling the flow structure near a diamond wing with slip are presented. A half-angle of a circular cone solution, inscribed in the inner dihedral angle between the flat wing consoles, was used as a control parameter to eliminate its fracture along the central chord. It is shown that such a control method is an effective means for eliminating vortex structures on the lee outer wing, when it is being flowed around with slip, that generate critical lines on the surface in a conical flow with intensive flow spreading around which high heat flows can occur in a real flow. The classification of vortex structures in the shock layer in the presence of rounding in the vicinity of the plane of symmetry of the wing is carried out. Criteria for the existence of Ferry vortex singularities in the absence of branching points of shock waves are determined.