Numerical evaluation of radiation absorption by a fluid confined in a semi-transparent circular cylinder

The energy absorbed by a fluid confined within a circular-cylindrical cover is calculated. Energy losses due to reflection on both sides of the inner and outer surfaces of the cover as well as the energy absorption of the cover are considered. Formation of ray cascades are taken into account. A ray tracing computer simulation was performed for various cover thicknesses, coefficients of extinction, cover diameters, and concentrations. A comparison of the energy absorbed for the circular geometry and of a flat surface geometry was also done. Optimization of the fluid diameter with respect to the amount of energy absorbed by the fluid per unit aperture was obtained.