Optimization of extreme ultraviolet mirror systems comprising high-order aspheric surfaces

Relaxation based Godunov type scheme for low mach multiphase flows

The present work is devoted to the numerical simulation of multiphase flows with two non-miscible compressible fluids. In this regime, interfaces can be tracked (Front tracking) or reconstructed (VOF, MOF). For theses approaches, interface topology changes and wave transmissions are difficult points. Diffuse interface methods are simple way to...

Avoiding unstable regions in the design space of EUV mirror systems comprising high-order aspheric surfaces

When Extreme Ultraviolet mirror systems having several high-order aspheric surfaces are optimized, the configurations often enter into highly unstable regions of the parameter space. Small changes of system parameters lead then to large changes in ray paths, and therefore optimization algorithms crash because certain sssumptions upon which they...

Upscaling of flow in porous media from a tracer perspective

Most of our knowledge of flow in porous media is obtained at the pore and the macro scale. For reservoir scale modelling it is not practical to model the flow at these fine scales. Considering the usual objectives (e.g. large scale flow pattern and production forecast) it is undesirable to have to gather the tremendous amount of fine scale data...

Standard linear solid model for dynamic and time dependent behaviour of building materials

Vibrations in building structures are almost always undesirable. Whether in the form of low frequency oscillations, or droning of the structure, or as audible noise, they may effect the comfort of the user. They may even effect the safety and the integrity of (parts of) the structure. Damping of mechanical vibrations has always been a point of...

Flight simulation fatigue tests on lugs with holes expanded according to the split-sleeve cold work method

Flight simulation tests on 2024-T3 and 7075-T6 lug specimens indicated significant fatigue life improvements obtained by expanding the holes in accordance with the split-sleeve cold work method. Geometrical distortions induced by the expansion were measured. The significance of residual stresses is analysed with reference to depth of penetration...