The Hypar Solar Cooker is a solar cooker with a hypar reflector developed by Kamath Design Studio about five years ago. The hypar surface is easily constructed using an old basket, bamboo and mud with embedded pieces of broken mirror (or any other reflective material). The curvature of the hypar surface helps to concentrate more sunlight on to the cooking food compared to a conventional flat reflector on a box solar cooker. The old basket gives shape to the base which holds a cooking pot with a glass lid. The mud acts as a cheap and readily available insulating material as well as an easily mouldable material to create the curved surface of the hypar on the bamboo framework. However, the exact shape of the hypar was, up to this point being found by trial and error.
I am now working on a digital tool that can customize the shape of the hypar based on the geographical location of the solar cooker, its orientation, and the time of the day it will be most used. The digital tool will give the lengths of the bamboo edge members and central members required to build the customized, optimal hypar shape. I hope to test the efficacy of this through physical prototypes as soon as the fog lifts off North India and we have more sun in Delhi. The main issue I want to test through the prototypes is how much the manual construction methods using bamboo, mud and mirrors deviate from the digitally derived hypar surface and the effect the deviation has on the performance of the reflector.