Numerical Analysis and Optimization of Thermal Performance of LED Filament Light Bulb

This paper presents numerical studies on thermal performance of LED filament light bulbs with different bulb sizes, phosphor diameters, and phosphor shapes. A quarter of numerical model of LED filament light bulbs was built to analyze the temperature field, velocity field and distributions for convective heat flux coefficient on the filament surface. The effects of bulb sizes, phosphor diameters and phosphor shapes on the thermal performance were investigated. The maximum temperature of a type of commercial LED filament light bulb reaches 145 °C, which can be reduced by the increasing of bulb sizes and phosphor diameters. When the phosphor diameter increases from 2 mm to 5 mm, the maximum temperature is reduced by 24 °C, which is also decreased by 10 °C with the increased bulb size of 4 mm. In addition, fin-shape filaments can effectively reduce the bulb temperature, and the maximum temperature reduction is 10 °C when the fin length reaches 0.91 mm.