"Tiny Cooling Fan" forced convection heat sink thermal resistance calculation Forced air cooling capacity than the natural air cooling can increase a lot. Because the air in the radiator cover is not uniform convection, so the forced air cooling thermal design is not easy to calculate. Here's the cover model by measuring the "Tiny Cooling Fan" wind speed to estimate the thermal method. First make a housing model, which includes housing shape, number and position of the fan, the direction of the wind over the radiator, the radiator layout surrounding components and the like. When "Tiny Cooling Fan" to work with the anemometer to measure air flow into and out of speed. It should be noted that the speed should be measured at the center of the radiator,