基于移动脉动源格林函数的小水线面双体船耐波性频域计算

Frequency Domain Computation Study on the Seakeeping Performance of Small-Waterplane-Area Twin Hull Based on the Translating-Pulsating Source Green Function

基于三维移动脉动(3DTP)源格林函数,针对安装稳定鳍的小水线面双体船(SWATH),计入两片体之间的水动力干扰、黏性和稳定鳍的影响,建立了SWATH耐波性频域计算方法.通过与SWATH试验模型(SWATH-M)的试验结果对比,验证了计算方法的可靠性,进而研究了航速对SWATH-M耐波性的影响,并分析了黏性和稳定鳍对SWATH-M整船所受水动力的贡献.结果表明,基于3DTP的船体运动计算结果与试验结果吻合良好.船体的运动响应算子随波长变化呈现出双极值.随着航速提高,短波共振区附近的运动响应算子极值增大,而长波共振区附近的运动响应算子极值降低.黏性和稳定鳍对阻尼系数的影响主要体现在垂荡-垂荡阻尼系数和纵摇-纵摇阻尼系数上,对波浪干扰力的影响主要体现在垂荡力虚部和纵摇力矩实部.

The seakeeping performance of a small-waterplane-area twin hull(SWATH)installed with stabilizing fins was investigated on the basis of the three-dimensional translating-pulsating(3DTP)source Green function.The effects of the hydrodynamic interaction between twin hulls,the viscous damping and the lift generated by the stabilizing fins were included.The numerical method was validated by comparison with the test results of a SWATH vehicle called SWATH-M.Then the influences of the forward speed on the seakeeping characteristic of SWATH-M were studied,and the effects of the viscosity and stabilizing fins on the hydrodynamic forces of the total hull were analyzed.The results obtained from the present method based on the 3DTP source Green function show good agreement with those of the test.The transfer functions of both heave and pitch modes depict two peak values with the wavelength increase.With the increase of the forward speed,the peak value in the relatively short wave zone increases while the peak value in the long wave zone decreases.The effects of the viscosity and stabilizing fins have obvious contribution to the heave-heave damping,the pitch-pitch damping,the imaginary part of heave force and the real part of pitch moment.