Abstract
In order to minimize the wind noise generated by a Sirocco fan, it is most important to understand the details of the flow field about a Sirocco fan. As the shape of a Sirocco fan is very complicated, it has not been very easy to capture the flow patterns. Presently, the authors have utilized the spark tracing method to visualize the flow field around a Sirocco fan and have observed the flow patterns between the blades with and without the intake load. It has been proved that the intake load causes the drastic changes on the inflow pattern and thus the changes of the flow pattern, which might be the major cause of noise, in the scroll chamber. In order to visualize the flow pattern between the blades of a rotating fan, presently the visualized images have been rotated digitally, instead of using complex image rotator such as Pecham prism.
