# 3D Geometry of a solar parabolic reflector composed of flat lamellae

This is how the 3D-layers of compressed light look like in the case of a parabolic reflector composed of flat lamellae(petals). For illustration is considered the computer built light-structure of a 12-petals-reflector, with D=800 mm, f=100mm, bottom opening 120mm.

Depending on the position relative to the focal plane, the adjusting between layers is of two different types. Each of the “above” layers 1-5 has a “cavity” of the size of the next layer. The only thick layer here is the lowest, the sixth - focal layer(the red one), which closes the structure from beneath. Each of the “under” layers 1-5 has a “bed” of the size of the next layer. Every “under” layer 2-6 fits “on” the previous layer. Every “upper” layer 2-6 fits “inside” the previous layer.

The extracting of the light-layers is performed separately for both areas. So we have six “upper” layers and six “under” layers, among them one “upper” focus layer and one “under” focus layer. Finally, the “above”- and “under” layers should be assembled together to form the complete body of light of the parabolic. Generally, for a reflector composed of 2n petals, n “upper” layers and n “under” layers of compressed reflected light should be distinguished in the total light beam.

The green layer represents reflected light of pure parabolic compression, with no intersection between lamella-light-bodies. Layers 2-6 are formed by superposition of two independent types of ray-compression: common parabolic compression in XY-plane and interlamellae-compression in XZ-plane.

The process of layer-extraction starts with constructing the 3D-lamella-light-body. Then comes the procedure of extracting (discovering) the compressed light layers, whose essential part are “INTERSECT” and “CUT”- operations between 3D-objects. The so extracted layers are being coloured and assembled back to form the structured light-body of the “above”- or “under” part.

Тhe 3D-focus layer of the flat petals deep parabolic consists of two parts – “under” and “upper”, which differ from each other in shape and volume. Compression geometry suggests that both focus components differ in the thermal effect they exert. The upper focus is a sidewise 12-rib-heater, the under focus is underwise 12-rib-heater. The vessel should be fitted to the size and form of the ribs.

I am glad you are teaching Bulgarians this wonderful technology. Now they can fall in love with solar cooked food. I think it tastes better than regular cooking. ( Sent to the Facebook page of HoSa Solar, August 8, 2016)