Raster angle impact on FDM-based additive manufactured fluidic oscillator

Journal article, 2022

The interior surface of a fluidic oscillator produced by FDM (Fused Deposition Modeling)-based additive manufacturing is associated with a directional pattern corresponding to the 3D printing raster angle. The present research explores the impact of raster angle α=0, 45, and 90° from three commercial 3D printers versus a CNC machined oscillator. The surface is characterized using an optical 3D measurement system. The performance of the emanated jet is assessed using hot-wire anemometry downstream of the outlet nozzle, and the required supply pressure is measured at the actuator inlet. Printer P1 with an actuator average roughness S̄a=8.3 μm and printer P2 with S̄a=29.9 μm inherit clear raster patterns while actuators printed by printer P3, more economical compared to printer P1, do not exhibit an evident pattern related to raster angle with S̄a=17.7 μm. Regardless of the type of printer and associated surface texture, oscillators with 0° raster angle provoke higher jet spreading accompanied by a lower required supply pressure compared to the milled sample. Strikingly, the performance for P30 and P390 is noticeably superior to the other printed oscillators and surpasses the milled actuator in terms of jet switching quality. Power-law fit is depicted to estimate the jet spreading versus surface roughness for each raster angle.