【作者】 贺伟；

【导师】 谭廷寿；

【作者基本信息】 武汉理工大学 ， 船舶与海洋结构物设计制造， 2006， 硕士

【摘要】 随着船舶向大型化和高功率方向发展,桨叶负荷的不断增大以及船尾流场的非均匀性,桨叶表面将不可避免的产生非定常空泡。非定常空泡将会导致诸如桨叶剥蚀,船尾振动,噪声等危害,甚至还会严重的影响螺旋桨的水动力性能,因此正确的预报螺旋桨非定常空泡对于如何减缓或避免这些危害,螺旋桨非定常轴承力的预估,激振力的计算以及抗空泡剖面的设计等方面将具有非常重要的理论和实用价值。 面元法作为目前流行的船舶流体力学计算方法,其力学模型较升力面理论更为完善,压力分布的预报计算也优于后者,但就螺旋桨合力的计算而言,两者基本具有同样的计算精度。对于螺旋桨非定常空泡问题,采用面元法计算繁复,工作量大,且存在不稳定性,而升力面理论发展成熟,计算快速且稳定,从工程实用的角度来看,采用升力面理论预报螺旋桨非定常空泡仍具有重要意义。 本文采用升力面理论预报螺旋桨非定常水动力性能及空泡性能。关键桨叶上的涡环强度和空泡源强在时域内通过迭代进行求解。非定常库塔条件的处理有多种,合适的处理方式有助于提高迭代收敛的速度,通过对不同处理方式的尝试比较,选取尾缘附近偶极子强度为多项式分布来满足非定常库塔条件。为了提高求解效率,在确定螺旋桨叶上空泡范围时采用弦向条向迭代方法,条带间的相互影响通过沿桨叶展向的迭代来考虑。 本文系统的研究了升力面理论预报螺旋桨非定常空泡性能,并编制了一套完整的预报螺旋桨非定常空泡性能的计算程序。通过对DTNSRDC系列桨以及HSP大侧斜桨的校核计算,表明本文提出的计算程序在螺旋桨敞水性能,非定常力,桨叶表面非定常压力分布以及空泡性能等方面均能取得令人满意的计算结果。 采用本文计算方法预报螺旋桨非定常空泡,对于螺旋桨激振力计算以及螺旋桨的权衡设计等方面具有重要的工程价值。更多还原

【Abstract】 With the development of ship in large-scale and high-powered, the load on the blade is increasing continually and the velocity field behind the ship is non-uniform, the unsteady cavitation will appear on the surface of blade inevitably. The unsteady cavitation will lead to some damage such as blade erosion, the vibration of ship structure and the propeller noise, or even effect the hydrodynamic performance of propeller seriously, therefore, the correct prediction of unsteady cavitation of propeller is possess of important theoretical and practical value in the assessment of how to reduce or avoid these damage, the prediction of unsteady shaft forces of propeller, the calculation of the vibratory forces and the design of unti-cavitation blade section.As the popular method for the calculation of marine hydrodynamics, the surface panel method has the advantage over the lifting-surface method in the mechanics model and the prediction of pressure distribution, but for the total force of propeller, they have the same computational accuracy. Using the surface panel method for the unsteady cavitation of propeller needs a very huge calculation work and the solution is instable, relatively, the lifting-surface method is more mature, the calculation is more rapid and stable, therefore, using the lifting-surface method for the unsteady cavitation of propeller is still have important engineering practical value.This paper has adopted the lifting-surface method for the prediction of unsteady hydrodynamic performance and cavitation performance of propeller. The intensity of vortex lattice and cavitation source on the key blade is solved by iterative scheme in time domain. There are several processing mode of the unsteady Kuta condition, a appropriate choice will improve the convergence velocity of iterative, this paper has choosed the dipole intensity near the training edge is polynomial distribution to satisfy the unsteady Kuta condition by compare experiment. In order to improve the efficiency of solution, a chordwise strip iterative method is adopted to determine the cavitation range of blade, the interaction between strips is included by spanwise iterative procedure.The prediction of unsteady cavitation performance of propeller is studied by using lifting-surface method systematically, and an intact computer program for the prediction of unsteady cavitation performance of propeller is set up in this paper. Through the verification calculations on DTNSRDC series propeller and HSP highly skewed propeller, the computer program presented in this paper can give a satisfied result of open water performance of propeller, unsteady forces, unsteady pressure distribution of blade surface and cavitation performance.Using the method presented in this paper to predict the unsteady cavitation of propeller has important engineering value in the calculation of the propeller vibratory forces and the off-design of propeller.更多还原