A numerical simulation an a pneumatic air table realized by micro-EDM

This paper presents a numerical simulation of the how field on a one-dimens ional pneumatic actuator. Unlike conventional actuators, this model uses dy namic pressure instead of friction to drive a slider. The objective of this simulation is to know the detail of the flow field un der the slider as well as the influence of its levitation on the horizontal transportation, Secondary vortices to be formed under the slider may cause an instability of the slider movement. To further assure a stable transpor tation of the slider, absence of secondary vortices in the gap is desirable , which can be achieved by narrowing the gap width, However, a too narrow g ap might cause a significant increase of dow impedance and thus sacrifice t he horizontal transportation. Here, two cases with gap width of 100 and 50 mu m were investigated. With a gap width of 50 mu m, there was no secondary vortex formed; however, the horizontal transportation was greatly sacrific ed, In contrast, with a gap width of 100 mu m, there were formed several se condary vortices of a size one to two times the gap width. However, the hor izontal driving force was about eight times larger than that in the case of a gap width of 50 mu m. [406].