Prerotacijski tok na vstopu v radialni rotor
Prerotation flow at the entrance to a radial impeller

slovenian

2000

volume 46, issue 5

Univerza v Ljubljani, Fakulteta za strojništvo

In the following paper an analysis is given of the prerotation flow in the entrance pipe of a radial turbomachine which occurs at partial load, i.e. during operartion under out-of-design conditions. Theoretically, the prerotation flow appears in the entrance pipe before the entrance in the radial impeller as a result of the real radial impeller operation. The final number of blades creates the impeller channels where the relative whirl flow exists, in addition to the around the the individual impeller blades. The result of the relative flow is also the separation of flow from the surface of the blade, especially at the entrance edge. The prerotation flow magnitude and direction depend on the operating regime, especially on the operating capacity. The experimental research is carried out at the entrance pipe of the radial fan. An anemometer with straight blades that are parallel to the pipe axis is used and placed at a distance of one and a half pipe diameters in front of the entrance edge of the impeller blades. The measurements were performed at three different impeller speeds and at different operating capacities.

16.09.2009