【作者】 方会东；

【导师】 苏玉民；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2008， 硕士

【摘要】 随着世界船舶业的发展,人们对船舶的航速以及主机的性能要求不断提高,但是由于船舶螺旋桨的尺寸受到各种限制而不能任意增加,故螺旋桨桨叶的负荷不断增大,在此情况下,螺旋桨往往无可避免的产生空泡现象。当螺旋桨出现空泡后,会对螺旋桨的性能产生不同程度的影响,或者使航速降低,或者使桨叶材料受到损害,或者使船体产生严重的振动和噪声等,因此在船舶设计阶段,对螺旋桨空泡进行理论预报是十分必要的。论文分析了国内外进行螺旋桨性能研究的技术特点,详细介绍了各国学者对螺旋桨空泡理论的研究进展,以及在螺旋桨空泡理论预报中存在的问题和解决策略。论文用理论的方法系统地分析了均匀流场和非均匀流场中的螺旋桨性能预报问题,包括螺旋桨定常水动力性能预报和螺旋桨非定常水动力性能预报。螺旋桨的非定常水动力性能采用时域方法求解,为了减少计算时间和降低计算机的存储量,论文采用了主桨叶方法,其它桨叶上的未知量均可由主叶片按一定相位角推算,在计算的每一时间步长的计算方法基本与定常时相同。论文采用基于速度势的低阶面元法预报了螺旋桨的空泡性能,包括空泡的长度和厚度等,并编制了相应的数值程序。本文以螺旋桨的每一个条带为研究对象。在预报空泡长度问题上,结合非定常性能计算压力分布,运用空泡产生条件解出空泡长度;在空泡厚度预报问题上,首先由格林公式推导出该问题的积分方程,然后在桨叶的每一个条带上离散方程,运用运动学边界条件、动力学边界条件、无穷远条件、压力库塔条件、空泡尾缘厚度为零条件等作为方程的定解条件,求解空泡区域的源汇强度和湿表面区域的偶极强度,根据空泡表面运动学条件,由求解出的空泡区域的源汇强度就能预报出空泡厚度。论文最后采用本方法和程序对PHS01桨进行了校核计算,并与试验结果进行对比,结果比较令人满意,表明了本方法在理论上的可行性。更多还原

【Abstract】 With the worldwide development of ship, the high speed and power of the ship are demanded for higher level. But the propeller’s dimensions limited by various conditions can’t increase randomly, the load on the blade is increasing continually, in this situation, the cavitatuon phenomenon will appear inevitably. The cavitation will lead to some bad effects on propeller performance, such as lowering the speed, the blade erosion, the unexpected structure vibration and radiated noise and so on, so it is necessary to predict the propeller’s cavitation performance in the ship design.This paper has analyzed the technology features in the domestic and foreign research of propeller performance and introduced the current technology of propeller cavitation. Some difficulties and tentative approaches in the research of cavitation performance have been referred.This paper has investigated the hydrodynamic performance of the propeller in the uniform and non-uniform flow field with theoretical method, which includes steady hydrodynamic performance and unsteady hydrodynamic performance. Unsteady hydrodynamic performance prediction is solved by time domain method. The key blade method has been used in order to reduce the computing time and storage, the unknown parameters of other blades are derived from the key blade by the corresponding phase angle. At each time step, the method is the same as the steady condition.This paper has adopted the low-order surface panel method based on velocity potential to predict the performance of partially cavity, which includes cavitation extent and thickness, and has compiled the corresponding numerical program. The solution method is carried out for each chordwise string. It is used of the cavitation happen condition to solve the cavitation extent combined with the pressure distribution in the unsteady hydrodynamic performance calculation. To predict the cavitation thickness, the integral equation is derived from Green formula, the solution condition including kinematic condition, dynamic condition, rigid object border condition, the far distance condition, the pressure Kutta condition and the zero thickness of cavitation trailing edge condition. Based on the kinematic condition on the cavitation panel, the cavitation thickness can be predicted by the solved source strength.Through the verification calculation on PHS01 propeller and compared with the test report, the computer program presented on this paper can give a satisfied result of cavitation performance, so this method is reasonable in theory.更多还原