NablaDot has contributed using fluid simulation to the lighting design in a shop window. This work has been carried out in collaboration with Efitekna – Efficient Technology for an end customer in the haute couture sector.

A potential problem with the lighting of a shop window like the one shown in the previous figure is the dissipation of the heat released by the LED bulbs used. These LEDs are arranged on an aluminium plate located between the different areas that form the structure of the shop window (air chambers, walls and spaces for maintenance). The heat dissipated by the LEDs can produce high temperatures in the aluminium plate, causing its deterioration and potential structural problems in the medium-long term.

The aluminium plate is located between two air chambers. In these chambers, air currents are generated by air temperature differences due to the heat dissipated by the LED bulbs. These air currents cool the aluminium sheet and exchange heat with other cooler surfaces, dissipating heat by conduction.

Therefore, the simulation of the cooling of the aluminium plate involves the combination of heat transfer by natural convection and conduction. NablaDot applied fluid simulation to this case to ensure that these heat transfer mechanisms were sufficient to provide proper cooling of the aluminium plate. The following figure and video show the calculated air velocity pattern, typical of natural convection phenomena (low velocities, disorderly flow combining updrafts and downdrafts).

Air velocity

The following figure and video show the temperature pattern in the air chambers and the aluminium sheet. Obviously, the aluminium plate is hotter, but, as the simulation found, it does not exceed the maximum operating temperatures indicated.

Air temperature

Thanks to fluid simulation techniques, it was possible to ensure a correct design of the shop window lighting, avoiding future problems much more costly than applying these calculation techniques.