CAJ | 학술논문

采用有限体积法对圆形四立柱涡激运动进行数值模拟。圆形四立柱涡激运动系统简化为两自由度的质量－弹簧－阻尼模型，引入雷诺平均应力模型求解不可压缩粘性 Navier-Stokes 方程，并结合 SST k －w 湍流模型对低质量比弹性支撑的圆形四立柱涡激运动进行模拟。将四阶 Runge-Kutta 代码嵌入用户自定义函数 UDF（User Defined Function）中求解四立柱的动力响应，采用动网格技术来实现立柱和流场之间的耦合。研究发现，圆形四立柱涡激运动流向和横向振幅随着折合速度的增大而先增大后减小，并出现幅值跳跃现象，跳跃点在折合速度9．0处。横向振幅最大值出现在折合速度为8．0时，大小为1．99D，远大于流向振幅最大值0．26D。圆形四立柱流向运动平衡位置随折合速度增大并非一直增大，在折合速度9．0时突然下降随后增大。圆形四立柱涡激运动出现了明显的频率锁定现象，锁定区间为5．0～8．0。当系统走过锁定系统后，流向幅值和流向幅值迅速减小。最后对不同折合速度下圆形四立柱运动轨迹和尾涡脱落模式进行讨论分析。
채용유한체적법대원형사립주와격운동진행수치모의。원형사립주와격운동계통간화위량자유도적질량－탄황－조니모형，인입뢰낙평균응력모형구해불가압축점성 Navier-Stokes 방정，병결합 SST k －w 단류모형대저질량비탄성지탱적원형사립주와격운동진행모의。장사계 Runge-Kutta 대마감입용호자정의함수 UDF（User Defined Function）중구해사립주적동력향응，채용동망격기술래실현립주화류장지간적우합。연구발현，원형사립주와격운동류향화횡향진폭수착절합속도적증대이선증대후감소，병출현폭치도약현상，도약점재절합속도9．0처。횡향진폭최대치출현재절합속도위8．0시，대소위1．99D，원대우류향진폭최대치0．26D。원형사립주류향운동평형위치수절합속도증대병비일직증대，재절합속도9．0시돌연하강수후증대。원형사립주와격운동출현료명현적빈솔쇄정현상，쇄정구간위5．0～8．0。당계통주과쇄정계통후，류향폭치화류향폭치신속감소。최후대불동절합속도하원형사립주운동궤적화미와탈락모식진행토론분석。
Here,the finite volume method was used to simulate vortex-induced motion of four circular columns. The vortex-induced motion system of four circular columns was simplified into a spring-mass-damping model.Reynolds-averaged Navier-Stokes solver was combined with SST (shear-stress transport)k-ωturbulence model for solving Navier-Stokes equation to simulate the vortex-induced motion of four circular columns with a low mass ratio.Fourth order Runge-Kutta method was manually written into the user defined functions to get the dynamic response of four circular columns, and then the dynamic mesh technology was adopted to realize the coupled fluid-structure interaction.It was shown that the amplitudes of the four circular columns firstly increase and then decrease with increase in the reduced velocity,'jump'phenomenon is observed in the amplitude curve at the reduced velocity of 9.0;the transverse maximum amplitude appears at the reduced velocity of 8.0,its value is 1.99D,much larger than the stream-wise maximum amplitude 0.26D;the in-line balance positions of four columns do not always increase with increase in the reduced velocity,it suddenly decreases at the reduced velocity of 9.0 and then increase;the frequency lock-in phenomenon occurs in four circular columns vortex-induced motion,the lock-in region is in the range of the reduced velocity of 5.0 ~8.0;when the vortex-induced motion system passes the lock-in region,the stream-wise amplitude and the transverse one suddenly decrease;finally,the trajectory and tail vortex shedding pattern of four circular columns at different velocities are discussed.