Electronics cooling by extended surface: Refractive index changes flow visualization of the natural convection heat transfer

摘要

Natural convection heat transfer occurs when the fluid buoyancy motion is induced by density differences themselves caused by the heating. A temperature gradient causes a density variation in a cooling fluid with a related local change in the refractive index. The gradient of refractive index has the effect of bending the light. The thermal load of the device causes an optical deflection in the cooling fluid that an opportune light probe can reveal. Analyzing the deflection of the light probe it is possible to go back to the related temperature gradient.