CAJ | 학술논문

以三类内孤立波理论KdV、eKdV和MCC的适用性条件为依据,采用Navier-Stokes方程为流场控制方程,将内孤立波诱导上下层深度平均水平速度作为入口边界条件,建立了两层流体中内孤立波对半潜平台强非线性作用的数值模拟方法.结果表明,数值模拟所得内孤立波波形及其振幅与相应理论和实验结果一致,并且在内孤立波作用下半潜平台水平力、垂向力及其力矩数值模拟结果与实验结果吻合.研究同时表明,半潜平台内孤立波载荷由波浪压差力、粘性压差力和摩擦力构成,其中摩擦力很小,可以忽略;水平力的主要成分为波浪压差力和粘性压差力,粘性压差力与波浪压差力相比较小却不可忽略,流体粘性的影响较小;垂向力中粘性压差力很小,流体粘性影响可以忽略. 此外,半潜平台对内孤立波的波形及其诱导流场的影响很小,因此采用Morison和傅汝德—克雷洛夫力公式计算其内孤立波载荷是可行的.
이삼류내고립파이론KdV、eKdV화MCC적괄용성조건위의거,채용Navier-Stokes방정위류장공제방정,장내고립파유도상하층심도평균수평속도작위입구변계조건,건립료량층류체중내고립파대반잠평태강비선성작용적수치모의방법.결과표명,수치모의소득내고립파파형급기진폭여상응이론화실험결과일치,병차재내고립파작용하반잠평태수평력、수향력급기력구수치모의결과여실험결과문합.연구동시표명,반잠평태내고립파재하유파랑압차력、점성압차력화마찰력구성,기중마찰력흔소,가이홀략;수평력적주요성분위파랑압차력화점성압차력,점성압차력여파랑압차력상비교소각불가홀략,류체점성적영향교소;수향력중점성압차력흔소,류체점성영향가이홀략. 차외,반잠평태대내고립파적파형급기유도류장적영향흔소,인차채용Morison화부여덕—극뢰락부력공식계산기내고립파재하시가행적.
According to the applicability conditions for three type of internal solitary waves theories includ-ing KdV, eKdV and MCC, a numerical method based on the Navier-Stokes equation in a two-layer fluid is presented to simulate the strongly nonlinear interaction of internal solitary waves with a semi-submersible platform, where the velocity-inlet boundary is applied by using the depth-averaged velocities in the upper-and lower-layer fluids induced by the internal solitary waves. The results show that the waveforms and am-plitudes of the internal solitary waves based on the present numerical method are in good agreement with the experimental and theoretical results, and the numerical results for the horizontal and vertical forces, as well as torques on the semi-submersible platform due to the internal solitary waves have good agreement with experimental results. It is shown that the horizontal and vertical forces on the semi-submersible plat-form due to the internal solitary waves can be divided into three components which are the wave and vis-cous pressure forces, as well as the frictional force, where the frictional force is small and can be neglected. For the horizontal force, their main components are wave pressure and viscous pressure forces, where the viscous pressure force is small but can not be neglected. For the vertical force, the component of the viscous pressure force is small and can be neglected. Moreover, the effects of the semi-submersible platform on the waveforms and flow fields induced by the internal solitary waves are small, and it is shown that the loads on the semi-submersible platform due to internal solitary waves can be calculated by the Morison equation and Froude-Krylov force.