Visualisation of Shock Waves in Hypersonic CFD Solutions

A new algorithm was added to the visualization system used at DLR’s Institute of Theoretical Fluid Mechanics to obtain the shock position from a numerical solution of a flow field. This assumes that the shock position is given everywhere in the flow field by the maximal gradient of a quantity like the density along the local flow direction. The local gradient vector is numerically calculated using an integral formulation which is easy to implement and insensitive even to degenerated grid cells which frequently occur in CFD grids. Thresholding techniques allow to distinguish significant portions of the shock patterns from weak numerical artefacts. Complex shock phenomena may be visualized by interactive manipulation of viewing transformations, clipping parameters or threshold values, thus enabling detailed examinations.