喷水推进器推进性能曲线的两种表示方法

Two methods for expressing the propulsive performance curves of marine waterjets

针对目前喷水推进器推进性能的表示方法较单一,指导船舶操纵不够便捷的现状,阐述了喷水推进器等功率线形式和等转速线形式推进性能曲线以及这2种表示方法的特点和各自的适用场合,并基于喷水推进基本理论和喷水推进泵外特性数据以原理框图的形式描述了2种形式性能曲线的求取方法.通过研究认为,等功率线形式的推进性能曲线更适用于喷水推进器选型,而等转速线形式的推进性能曲线用于指导喷水推进船的操纵使用或用于描述采用计算流体力学数值计算得到的推进性能时更加方便.

At present,there is only one method for expressing the propulsive performance curves of marine water jets and it does not provide useful input for the maneuvering of ships.In this paper two methods for expressing performance are put forward： one is in the form of a constant-power curve and the other in the form of a constant-rotational-speed curve.Their features and applicability are addressed.The approach used to formulate both forms of propulsive performance curves was elaborated by means of schematic diagrams based on water jet propulsion principles and data on pump characteristics.Analytic results showed that the constant-power propulsive performance curves are more applicable to selection of a type of water jet,while the constant-rotational-speed propulsive performance curves are more useful for planning ship maneuvering methods or for calculating propulsive performance.