Bounding Volumes
Verfahren zur Berechnung der Viewfaktoren für Strahlungsprobleme
Author
Michael Fleischmann
Supervisors:
Prof. Dr. Peter Rentrop,
Technische Universität München
Dr. Stefan Paulke,
P+Z Engineering GmbH
Abstract
View factors are needed for the calculation of radiation exchange between diffusely reflecting and absorbing so-called Lambertian surfaces. A view factor is a measurement for the portion of radiation energy leaving one surface and being received by another surface. It can be used in radiation models to simulate the surface-to-surface radiation exchange, e.g. in grey-body radiation.
Besides evaluating the view factor integral numerically, the main part in calculating a view factor is to determine the visibility between the surfaces. Since the number of obstruction tests is quadratically in the number of the elements in a finite element mesh and due to the steadily increasing number of elements in these meshes, the need for sophisticated algorithms to determine the visibility arises.
This thesis presents some fundamental variants of the view factor integral and analyses hierarchical methods for ray tracing in a FE mesh to perform visibility tests.
|
Download full text [pdf, 3 MB] (german) |