Assessment of Various Trombe Wall Geometries with CFD Study

Abstract

An investigation of the optimal geometric configuration of a Trombe wall is presented with simulation of the transfer phenomena, that take place during its operation, using computational fluid dynamics. A numerical model is developed for a 2D steady-state simulation of a Trombe wall cross-section operation, and it is validated against an energy balance model’s results. Then the developed model is used for the evaluation of 10 different geometrical configurations examining various air gap widths, storage wall thicknesses, ventilation slots distances, and ventilation slots diameters. The examined geometries were evaluated with respect to the achieved temperature at the air gap exit and at the room facing storage wall surface, the achieved mass air flow in the air gap, and the ability of warm air stream from the gap to enter the test room. The aim was to ventilate the whole space without leaving large areas where the air just recirculates unaffected by the Trombe wall operation. According to the above-described criteria, optimum solution is an air gap width of 5 to 8 cm with increased distance between ventilation slots and a configuration of upper ventilation slot with an inclination of 30 degrees.