Heliostat Cosine-Efficiency & Flux Map (2D)

This top-down companion to the 3D receiver simulation replaces its illustrative mirror tilt with real solar geometry: each heliostat's cosine efficiency and reflection direction are derived from the actual angle between the sun's direction and the heliostat-to-tower direction, using the same half-angle bisector law that governs real heliostat field optics. Combine that with an empirical clear-sky atmospheric transmittance model for the slant path, and the reflected power each mirror contributes to the receiver is now physically grounded rather than uniform. That power is spread across the receiver's flux ring as a Gaussian aim-point footprint, and a live steady-state radiative-plus-convective energy balance turns the resulting flux map into panel temperatures in real time as you sweep the sun's elevation and azimuth, the field size, aim spread, irradiance and wind speed.