TheElucidation of the Structure between Space Time of the Sea Wind, and Calculation of Wind Load which Acts on Mega-Float Offshore Structure

基于多点风速仪对海面附近波浪和风海进行连续测量的结果，研究了粗糙度参数Z_O和摩擦系数C_D的平均风速分布，并考虑了其与显著波高（H_<1/3>）的关系。此外，我们还考虑了无量纲粗糙度参数gZ_0/u*^2与波浪年龄C_P/u*的关系，以及反映海面情况的无量纲参数u*^2/ σ_p与摩擦阻力系数C_D的关系。在此基础上，对紊流特性的湍流强度和湍流谱进行了研究、比较和检验。利用海洋技术综合研究所（国土交通省）在Oigawa河口附近250米的地方进行观测。采用多点风速仪的8个传感器每隔0.5 ~ 1.5m安装在杆上进行风速测量。此外，还对超声波水位计、精密压力表、温度计和超声波风速计进行了同时测量。采样时间为5Hz， 1次测量的数据个数为16384。主要结果如下：粗糙度参数Z_0随标准风速（V_<10>）的增大而增大，在V_<10>>8m时，增大幅度较大。在这个2.4m/s的测量范围内设置为0.00023<Z0<0.034。其次，要求为卡门常数k=0.4的摩擦系数（C_D）随着标准风速（V_<10>）的增大而线性增加，在该测量风速范围内设为0.0014<C_D<0.0049。在0.8 ~ 1.2m范围内，随着有效波高（H_<1β>）的增加，摩擦系数（C_D）呈指数增长；随着粗糙度参数（Z_0）的增加，摩擦系数（C_D）呈指数增长。这与Toda和Koga（1986）根据无量纲粗糙度参数gZ_0/u* 2与波龄C_P/u*之间的关系，在波龄较大的区域内提出的公式基本一致。在摩擦阻力系数（C_D）与无量纲参数（u*2/ σ_p）的关系中，u*2/ σ_p的增加也会增加C_D。无量纲风速谱成为相对接近Hino的谱形式和Davenport的谱形式的值，接近低频侧的谱峰。然而，在高频侧得到的衰减结果比Davenport、Hino和Ochi、Shin的频谱形式更大。少

Based on the result which carried out continuation measurement of the wave and the wind-sea near the sea surface using the multi-point anemometer, this research asked the average wind velocity distribution for the roughness parameter (Z_O) and the friction coefficient (C_D), and considered the relation with the significant wave height (H_<1/3>). Moreover, we considered the relation between a non-dimension roughness parameter (gZ_0/u*^2) and a wave age (C_P/u*), and the relation between the non-dimension parameter (u*^2/υσ_p) showing a sea surface situation, and a frictional resistance coefficient (C_D). Furthermore, past research, and comparison and examination were performed about the turbulent intensity and spectrum which are the turbulent flow characteristic. Observation was performed using the sea technical general research institution (Ministry of Land, Infrastructure and Transport) in the place of 250m of the Oigawa mouth-of-a-river offings. Wind velocity measurement was performe … More d by attaching eight sensors of a multi-point anemometer in the pole for measurement at intervals of 0.5-1.5m. Moreover, simultaneous measurement also of an ultrasonic water gauge, fine pressure gauge, a thermometer, and the ultrasonic anemometer was attached and carried out. Sampling time is 5Hz and the number of data of 1 measurementis 16384.The main results are as follows. A roughness parameter (Z_0) tends to become large as standard wind velocity (V_<10>) increases, and in V_<10>>8m, the increase rate became large. It was set to 0.00023<Z0<0.034 in this 2.4m/s that carried out the measurement range. Next, the friction coefficient (C_D) for which it asked as a Karman constant k=0.4 increased linearly as standard wind velocity (V_<10>) became large, and it was set to 0.0014<C_D<0.0049 in this measurement wind velocity range. Moreover, a friction coefficient (C_D) increases exponentially as the significant wave height (H_<1β>) increases in the range which are 0.8-1.2m, a friction coefficient (C_D) increases exponentially as a roughness parameter (Z_0) increases. It was mostly in agreement with the formula which Toda and Koga (1986) proposed in the domain to which the wave with large wave age progressed enough from the relation between a non-dimension roughness parameter (gZ_0/u*^2) and a wave age (C_P/u*). In the relation between a frictional resistance coefficient (C_D) and a non-dimension parameter (u*2/υσ_p), an increase of u*^2/υσ_P also increases C_D. I am doing one The non-dimension wind velocity spectrum became a value comparatively near the spectrum form of Hino the spectrum form of Davenport, and near the spectrum peak at the low frequency side. However, A result with larger attenuation than Davenport, Hino, and the spectrum form of Ochi and Shin was brought at the high frequency side. Less