Abstract
In the present study, the wind velocity of piezoelectric fans is measured by using a hot-wire anemometer. The distance between the fan and the probe of the hot-wire anemometer is maintained at 1 mm for all measurements. It is found that the wind velocity of up and down or left and right areas are symmetrical. It is therefore convenient to just measure the velocity distribution of one area for simplicity. In addition, the fan is tested in both vertical and horizontal orientations. The flow rates are the same for both orientations. For the same tip displacement, a wider blade can generate the larger flow rate. When the tip displacement is below 4 mm, 90 percent of total flow rate can be evaluated by solely calculating the flow rate within the blade width. Moreover, the relationship between the tip displacement and flow rate, RA, RQ, RU, and R is studied. RA represents the sweep area of the blade relative to the total area subject to flow field influence. RQ represents flow rates in the sweep area of the blade relative to the total flow rate generation. RU represents the maximum wind velocity on the blade tip over the blade tip velocity. R represents the average wind velocity on the blade tip over the blade tip velocity. It is found that the flow rate is linearly proportional to the tip displacement. However, RA、RQ、RU and R decrease with the increase in the tip displacement. The trend of decline between RA and RQ is similar while that between RU and R is similar.