The complete eigensystem, including eigenvalues and left and right eigenvectors, of the Euler equations of inviscid flow are derived in a general finite volume coordinate frame. The symmetry of the eigenvector space is demonstrated from a mathematical and geometric viewpoint. Results are presented for 2-D and 3-D inviscid flow, and their application in computational fluid dynamics (CFD) is discussed.

This paper is concerned with the application of a new Space-Time Mapping Analysis (STMA) method to a nonlinear, inviscid computation of unsteady airfoil response to an impinging, highintensity, vortical gust. The method solves the unsteady problem as a steady-state one by treating the time coordinate identically to the space directions. A high-order discretization scheme is provided to achieve time-accurate predictions of both unsteady aerodynamic and aeroacoustic responses. The obtained results show localized zones in the computational plane where nonlinear response effects become important.

In the presented work, a new numerical approach to computational aeroacoustic (CAA) problems based on a modified total variation diminishing (TVD) scheme is examined in order to investigate its value as a possible alternative to the more computationally expensive schemes currently used in CAA. Such schemes generally rely on high-order dispersionrelation-preserving (DRP) algorithms. The method is applied to the direct numerical analysis of an unsteady, compressible, viscous 2-D flow over a cylinder at a Mach number of 0.5 and a diameterbased Reynolds number of 100,000. The acoustic signal is extracted directly from the unsteady flowfield solution at several radii and compared to the acoustic predictions based on the Potential-Theoretical Method.

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A new CD measuring tool is described, Carl Zeiss Axioscan, which is based on confocal scanning technology. The advantages of having a great variability in choosing the illumination is demonstrated with several examples. Selection of deep UV illumination increases the lateral and height resolution of the system. Matching the illumination to the optical constants of the materials to be measured enhances the reproducibility and the accuracy of the measurement.In the description of the system,it is shown how the confocal scanning technique can be implemented with conventional light sources, and how this increases the flexibility in illumination conditions.