Red-flap grid Blue-back ground cut out box Blue-rigid Red-elastic

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Red-flap grid Blue-back ground cut out box Blue-rigid Red-elastic

As mathematical model for the light propagation in highly scattering media the diffusion equation for the photon density is used. The solution of the forward problem obtained by the Finite Element Method (FEM) is compared with the analytical solution in a rectangle homogeneous domain. The application of a numerical method as the FEM allows to take into account different geometries and various embedded objects. For the inverse imaging problem two reconstruction methods are introduced acting as iterative algorithms based on the FEM forward model. As cost function the 12-norm of output flux differences for a selected combination of times, detector and source positions is used. The effectiveness of the image reconstruction method is demonstrated by some instructive examples.

Vortex dominated flows appear in many flow simulations such as wake turbulence of an aircraft or a delta wing at a high angle of attack. For detailed investigations of vortex breakdown, vortex interactions or tracing vortex cores, an automated grid adaptation with suitable vortex indicators is essential. Physical indicators, e.g. the vorticity magnitude or the total pressure loss, are in most cases not sufficient for correctly identifying a vortex core. This paper presents advanced vortex core indicators which properly identify a vortical structure independent of the flow case. These vortex indicators are tested in typical flow applications to determine the right cutoff value which is important for an automated adaptation procedure. A grid refinement for a delta wing testcase in combination with the newly introduced vortex indicators will demonstrate the improvements compared to the standard pressure loss indicator.