The optical simulation of a linear parabolic solar collector with a tubular receiver is presented. The simula- tion considers a general model of a trough collector with a pipe receiver, with or without a glass covering, and with a realistic solar irradiation from an arbitrary direction. Optical properties can depend on the wavelength. The simulation is performed using a three-dimensional ray-tracing technique and allows us to follow a ray along all the multiple reflections and refractions that occur at the mirror and at the receiver. Defects of various kinds are simulated. The simulation computes the total optical efficiency, the distribution of the absorbed radiation on the surface of the receiver, and the energy absorbed by the glass covering (if present). The results for a typical trough electric production system are shown and commented upon.

I answered earlier

Thank you Dr Ali Alwaeli for your replay. based on your answer and the published paper, the calculated ratio therefore corresponds to the total optical efficiency. In addition, I kidnly ask you if I can use a DNI file instead of a single value, if you have already worked with the soltrace software.