Sand Battery Simulator

Heat flow through a solar-heated box of sand, solved on a regular grid and checked against the heat equation.

Setting up…

Temperature, °C
Drag to turn; right-drag, shift-drag or two fingers to move; wheel or pinch to zoom toward a point; double-click to reset.
0 s
Day by day
Input data

Over the whole run

The circuit lumps the box into five heat capacities joined by thermal resistances, each worked out from the design and fitted to the mesh model, whose fuel it matches within about 10 %. Here the values are set by hand and fixed: the sand's heat capacity and the insulation's conductivity no longer change with temperature, and no layer limit applies.