Measurement of flow inside a vacuum cleaner head

Vacuum cleaner heads with rotating brushes are widely used as a home appliance. Although it efficiently collects dust from the floor, the flow field of air and the motion of the dust inside the head have not been fully investigated. In this study, we clarified the flow inside the cleaner head using 3D-PTV. We measured mean velocity distributions with/without rotating brush. Without brush, the fluid flowing from the front of the head was sucked into the rear of the head and then flowed into the suction port while circulating around the axis of the rotating brush along the casing. In addition, we observed that there was reverse flow near the suction port. With stationary brush, it turned out that the stationary brush blocked the flow. It was confirmed that the flow was decelerated by the brush and went toward the suction port while circulating in the region between the brushes. With rotating brush, the fluid near the floor was moved along the path of the brush tip without being prevented its motion by the brush, and directly flowed into the suction port.