FEM-based simulation of continuous wear of CrAlN-coated tools

The understanding of the correlation between the coating-specific properties of PVD-coated cutting tools, the thermomechanical loads on the cutting wedge and the resulting tool wear, is necessary to avoid costly iterative test series. To obtain this knowledge a hybrid approach based on experimental tests and FEM-based chip formation is used in this study. In this respect, in a first step, a suitable wear rate model is derived and parameterized on the basis of wear analogy tests and experimental machining investigations. This wear rate model is then coupled with the FEM-based chip formation simulation to predict continuous tool wear

Development and optimization of the IPM MM5 GPS slant path 4DVAR system

This article describes the development of tools for routine 4-dimensional variational data assimilation of Global Positioning System Slant Total Delay (STD) data in the framework of the MM5 system at the Institute of Physics and Meteorology of the University of Hohenheim. The Slant Total Delay forward operator is introduced which allows model validation and the assimilation in the Message-Passing Interface environment. An experiment is conducted which highlights the importance of accurate model physics in the variational assimilation system. We demonstrate that the model minus observation statistics of STD data crucially depends on the convection scheme and the implementation of horizontal diffusion. A set of modifications to the existing non linear, tangent linear and adjoint model is presented. These include an improvement of the horizontal diffusion scheme and the implementation of the Grell cumulus convective scheme in order to eliminate the observed systematic tendency in the model minus observation statistics of the STD data and precipitation in mountainous terrain. A first assimilation experiment with the improved MM5 variational assimilation system shows promising results

A review of the remote sensing of lower tropospheric thermodynamic profiles and its indispensable role for the understanding and the simulation of water and energy cycles

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