Theoretisch berechnete Transmissionswerte für geneigte Wabenstrukturen

Abstract

Usually honeycomb or capillary structures are produced with cell orientation perpendicular to the layer. However, if the cells have an inclination with respect to the surface normal, the thermal radiation heat transport and therfore the U-value will be lowered. A second positive effect may be the optimal orientation of the cells with respect to the sun's orbit. Structures of this kind have already been investigated experimentaly /1/, but in order to optimise the inclination of the cells for a specific application, a theoretical model is needed. One part of this work is an algorithm to calculate transmittance for every incidence angle from two special transmittance curves /1/. These curves are calculated by a ray-tracing method based on another work /2/. By now the transmittance for every set of azimuthal and polar incidence angles (Phi, diameter) may be calculated for every possible orientation of the honeycomb cells. Different cell orientations may cause rather different variations of monthly transmittances. This may be used in order to control seasonally the solar gains of collector systems.