喷水推进器功率特性与航速相关性研究

Research of relationship between waterjet power absorption and ship speed

通过对某船喷水推进系统的分析,研究了喷水推进器的功率特性(功率与转速的关系)与航速的关系.先由喷水推进动力学方程引出喷水推进器功率特性在喷水推进系统稳态特性和动态性能研究中的作用,然后分析了KaMeWa71SⅡ喷水推进器的转速特性,将转速特性变换成力矩特性后,分析了该力矩特性,并将其与螺旋桨相应特性作了对比.根据转速特性获得的3个不同航速下的喷水推进器功率与转速的关系曲线,分析了航速对功率特性的影响,同时也将其与螺旋桨的相应特性曲线作了对比.研究所得出的结论是:喷水推进器的功率特性不是唯一的,装船之后它的功率特性受航速影响,但这个影响不像螺旋桨那么显著.据此推得,喷水推进系统在“船—泵—机”的匹配设计以及实际使用中,主机一般不会超负荷.

The relationship between the waterjet power absorption and ship speed is analyzed by a case study about anewly-designed waterjet propulsion system. Firstly, from the application of the dyna- mic equations of waterjet propulsion system the waterjet power absorption characteristic isintroduced in the research ofsteady-state and dynamic propertiesof the waterjet propulsion system. Then the torque property of the waterjet is analyzed after the rotary speed curvesof the waterjet, i.e. the rotary speed versus absorbed power & boat speeds, are transformedto the torque curves, which iscompared with the screw propulsion systemas well. The effect of ship speed onthe waterjet power absorption characteristic is analyzed after three power absorption curves at different ship speedsare obtained according to the rotary-speed curvesof waterjet, and these power absorption curves are also compared with those of the screw propulsion system. The conclusions drawn from the research are that the characteristic of the waterjet power absorptiondoes not present uniqueness, and it will be affected by the ship speed after installed on board a vessel, but such an influenceon the characteristic of the waterjet power absorptionby ship speed is not as remarkableas that in the propeller′s propulsion. A ratiocinationfrom the conclusions is gotten that the prime mover in waterjet propulsion will not be overloaded in matching of hull-waterjet-engine and in service.