Calculation of radiative losses of solar receivers using viewfactors

This presentation describes a new implementation of the view factor model into OpenFOAM, an open source CFD code. The original model is based on double area integration of the view factors whereas much better results can be achieved by using double line integration or even single line integration. With the presented model view factors can be modeled for technical meshes with an error of less than 0.001 compared to the analytical solution. Moreover, further boundary conditions necessary for the simulation of thermal receivers have been presented. These boundary conditions are used to couple radiative with convective heat transfer on adiabatic walls.