Topology Optimization for Maximum Daily Solar Radiation for a Large-Scale Non-tracking Heliostat Solar Reflector Using CFD Analysis

The present research work proposes a method to optimize the geometrical parameters of a large-scale heliostat reflector using CFD analysis. The use of heliostat reflectors in solar cookers is well established because of its low-cost production. Determining the best configuration of a fixed shape of inverted frustum of a square pyramid reflector is very helpful as it can avoid the tracking of reflector. The reflector height and dimensions of sides of the top surface are kept constant which are 1.75 and 5 × 5 m2, respectively. Results are obtained by varying the dimensions of the bottom sides of the reflector by 5%. All 32 combinations are tested for a time interval of 15 min considering daily radiation data for the time period starting from 0900 to 1700 h. To analyze the effect of these varying parameters, total daily radiation heat flux at the top and base is calculated, and a dimensionless concentration factor is calculated to get the topology optimization. Two dimensionless parameters are identified, viz., height-to-base ratio and area ratio of top to bottom surface, the values of which are 0.7 and 2. These dimensionless geometrical parameters can be utilized to manufacture heliostat solar reflectors.