借助模型试验方法,分别对圆柱和方柱式张力腿平台进行了涡激运动试验研究。研究发现,立柱截面形式对张力腿平台尾涡脱落模式、横向运动幅值、振荡频率和运动轨迹等涡激特性有较大影响。圆截面立柱时,涡激阻力频率是升力频率的两倍,平台的涡激运动响应以横向为主(约0.6D),运动轨迹为较规则的扁“8字形”,并随来流角度不同呈肥瘦变化;而方截面立柱时,涡激升阻力频率关系和运动轨迹随来流角度的不同而变化,且横向和顺流向运动幅值大体相等(约0.1D),远小于圆截面立柱平台的涡激响应。
In order to study vortex induced motions (VIM) of two columns of tension leg platform (TLP) with different cross-section, a model test was carried out. The results show that section of the column has greater impact on the vortex shedding pattern, responsive transverse amplitude, oscillation frequency and trajectory. For cylindrical cross-section of TLP, the frequency of the drag force is roughly twice that of the lift force, and the transverse motion has the predominate position. The motion of the TLP has regular flat '8'-shaped track and it will be changed to fat or thin with different current incidences. For square cross-section of TLP. the frequency of the drag/lift force and the motion trace will vary with different current incidences. In addition, the inline and transverse responsive amplitude are substantially the same and they are far less than the vortex induced response of the cylindrical cross-section of TLP.