船舶力学
船舶力學
선박역학
JOURNAL OF SHIP MECHANICS
2015年
4期
369-380
,共12页
谷家扬%陶延武%杨建民%肖龙飞
穀傢颺%陶延武%楊建民%肖龍飛
곡가양%도연무%양건민%초룡비
涡激运动%张力腿平台%动网格%UDF
渦激運動%張力腿平檯%動網格%UDF
와격운동%장력퇴평태%동망격%UDF
vortex induced motion%tension leg platform (TLP)%dynamic mesh%user defined functions
平台涡激运动易导致立管及系泊系统疲劳损伤,危害其安全稳定性。该文引入雷诺平均法求解NS方程结合DES湍流模型对不同流速下深水张力腿平台三维涡激运动及流场特性进行了数值研究。采用GAMBIT软件建立计算网格,将求解动力学控制方程的代码嵌入UDF求解器中,采用动网格技术实现流场更新并求得作用于平台立柱和浮箱上的瞬时升力和拖曳力。采用最大值统计法和均方根统计法进行数据统计。研究发现:张力腿平台涡激运动流向振幅的大小随着约化速度的增大而增大,但在小范围内波动;横向振幅曲线最大值出现在0°来流、约化速度U*=8.0处,大小为0.38D;三种来流工况流向平衡位置随无因次速度的增大而增大,但增长速度有所区别,22.5°和45°下流向平衡位置的增加速度要明显大于0°来流;22.5°来流升力系数谱能量较为分散,立柱及浮箱之间的干扰具有强非线性效应;最后对张力腿平台表面压力系数分布及涡量等值面特性进行了分析和探讨。
平檯渦激運動易導緻立管及繫泊繫統疲勞損傷,危害其安全穩定性。該文引入雷諾平均法求解NS方程結閤DES湍流模型對不同流速下深水張力腿平檯三維渦激運動及流場特性進行瞭數值研究。採用GAMBIT軟件建立計算網格,將求解動力學控製方程的代碼嵌入UDF求解器中,採用動網格技術實現流場更新併求得作用于平檯立柱和浮箱上的瞬時升力和拖抴力。採用最大值統計法和均方根統計法進行數據統計。研究髮現:張力腿平檯渦激運動流嚮振幅的大小隨著約化速度的增大而增大,但在小範圍內波動;橫嚮振幅麯線最大值齣現在0°來流、約化速度U*=8.0處,大小為0.38D;三種來流工況流嚮平衡位置隨無因次速度的增大而增大,但增長速度有所區彆,22.5°和45°下流嚮平衡位置的增加速度要明顯大于0°來流;22.5°來流升力繫數譜能量較為分散,立柱及浮箱之間的榦擾具有彊非線性效應;最後對張力腿平檯錶麵壓力繫數分佈及渦量等值麵特性進行瞭分析和探討。
평태와격운동역도치립관급계박계통피로손상,위해기안전은정성。해문인입뢰낙평균법구해NS방정결합DES단류모형대불동류속하심수장력퇴평태삼유와격운동급류장특성진행료수치연구。채용GAMBIT연건건립계산망격,장구해동역학공제방정적대마감입UDF구해기중,채용동망격기술실현류장경신병구득작용우평태립주화부상상적순시승력화타예력。채용최대치통계법화균방근통계법진행수거통계。연구발현:장력퇴평태와격운동류향진폭적대소수착약화속도적증대이증대,단재소범위내파동;횡향진폭곡선최대치출현재0°래류、약화속도U*=8.0처,대소위0.38D;삼충래류공황류향평형위치수무인차속도적증대이증대,단증장속도유소구별,22.5°화45°하류향평형위치적증가속도요명현대우0°래류;22.5°래류승력계수보능량교위분산,립주급부상지간적간우구유강비선성효응;최후대장력퇴평태표면압력계수분포급와량등치면특성진행료분석화탐토。
Vortex-induced motions of platforms are associated with rise and mooring system’s fatigue dam-age, which also endanger its security and stability. This paper studies the 3D vortex-induced motion and the flow field characteristics of deepwater TLP under different current velocities based on RANS (Reynolds-Av-eraged Navier-Stokes) solver for N-S equation combing with DES (Detached eddy simulation) turbulence model. Computational grid was set up by GAMBIT software and the code of solving dynamic control equa-tions was embedded to UDF (User Defined Function). The instantaneous drag and lift forces of the columns and pontoons can be solved after the flow field renewal is achieved by dynamic mesh technology. The maxi-mum statistical method and nominal statistical method were used to analysis the simulation results. The results indicate that the maximum stream-wise amplitude of TLP increase with the increase of reduced ve-locity, but it fluctuates on a small scale. The maximum transverse amplitude happen at the reduced veloci-ty of 8.0 from 0 degree current, and the value is 0.38D. The stream-wise equilibrium position of three dif-ferent flow approach angles increase with the increase of reduced velocity, but the growth rate is different. The growth rate of 22.5 degrees current and 45 degrees current cases is lager than the 0 degree current case. Spectrum energy of lift coefficient is relatively decentralized and the interference between column and pontoon has nonlinear effect. Finally, the pressure coefficient distribution and vorticity iso-surface charac-teristics of TLP surface are discussed.