ANALYSIS OF AXIAL-FLOW PUMP DISCHARGE FLOW AND ITS INFLUENCE ON MEASUREMENT OF HEAD AND HYDRAULIC LOSSES IN THE DISCHARGE PIPE

摘要

The outlet energy of an axial-flow pump measured by conventional method was found on trial to be below its real value. For finding out the reason, we measured the outlet flow field with a global five-hole probe. The results indicate that the flow has remarkable circular velocity, the axial velocity is bad-distributed, static pressure is low in periphery and great in center. The flow in the discharge pipe is spiral and nonuniform. Hydraulic losses in the discharge pipe are not in direct proportion to the square of discharge and are also relevant to circular velocity. Generally, the greater the circulation is, the greater the hydraulic loss is. This paper proposed a amending method of the outlet energy and head measured by conventional method.