抄録
The value of a jet pump lies in its simplicity, its ability to pump multiphase fluids. However, its efficiency is much below a centrifugal pump. One main reason why jet pump efficiency is low occurs in the large friction loss in the throat, which needs enough length to mix the driving and induced fluids. To obtain fundamental knowledge of the effect of surface roughness in the throat on jet pump performance, experimental studies were performed for a typical single nozzle jet pump using water at room temperature. It was revealed that surface roughness located nearer the throat inlet had a greater effect on the jet pump efficiency because the local skin friction coefficient nearest the throat inlet was the larger. The best efficiency and its flow rate ratio decreased linearly as surface roughness increased. The frictional resistance coefficient in the throat for each roughness became obvious by fitting a one-dimensional theoretical prediction equation to the experimental results.
