用准定常升力线理论预报螺旋桨在非均匀流场中的性能

本文应用准定常升力线理论预报船用螺旋桨的性能,建立了适合中型计算机的程序。通过四个桨模的敞水试验和性能计算结果比较表明,对于计算螺旋桨的推力与转矩系数,只要应用升力线理论加上简单的粘性经验修正及升力面影响修正,不必作边界层计算即可得到比较满意的结果。伴流场中单个叶片推力与转矩脉动计算表明,用升力线作计算时,伴流产生的水流弯曲对推力、转矩脉动有较明显的影响,对推力偏心度则影响不大,计算所得的推力、转矩脉动可供计算主机扭振及轴系振动的外力作参考。

PREDICTION OF PERFORMANCE CHARACTERISTICS OF PROPELLER OPERATING IN A NONUNIFORM WAKE FIELD BY QUASI-STEADY LIFTING LINE THEORY

In this paper, a method based on quasi-steady lifting line theory for the prediction of performance characteristics of a propeller working in a non-uniform wake field is presented. A computer programme fit for medium size computer has been developed in China Ship Scientific Research Center (CSSRC) for performing this calculation. A satisfactory agreement between results of model tests and computations based upon the lifting line theory with corrections for viscosity and lifting surface effects can be obtained and the boundary layer calculation seems to be unnecessary. It is found that in predicting the thrust and torque fluctuations acting on one blade of a propeller, we have to take the curved inflow of wake field into account, while the thrust eccentricity is for less sensitive to the curved inflow.The values of thrust and torque fluctuations obtained from this calculation can be used as the reference of external forces for the estimation of torsional vibration of an engine and vibration of a shaft system.