The study of emittance distribution along the walls of a cellular anti-losses structure, associated to a base surface whatever being the index emission shape

Anti-losses cellular structures are a device allowing the reduction of radiative losses existing in solar absorbers by modification of radiative transfers upon the collecting surface. This device is composed of prismatic cells, normal to the surface to be protected which so constitute the base of the cells. To study anti-radiative properties of such devices, it is necessary to determine the emittance distribution along the walls of one cell. The works done until now were concerned with black or diffuse grey surfaces, in the field of far infrared (λ > 3 μm). Having given the results relative to both these types of surfaces, the authors are presenting in this paper a method for determination of emittance distribution along a cell walls, whatever being the shape of emission index for far infrared, and the reflection on to the surface being only a specular one. Then, the method is applied to two special situations in which the index is ellipsoidal.