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

海风时空结构解析及巨型浮体海上结构风荷载计算

• 批准号: 11650953
• 负责人: TANAKA Hiromichi
• 金额: $ 2.11万
• 依托单位: TOKAI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650953/
• 关键词: Sea-wind; Mega-float offshore structure; Roughness parameter; Friction coefficient; Non-dimension spectrum; Wave age; 摩擦係数; 風速変動スペクトル; 風荷重; 乱流特性

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

本研究在利用多点风速计对近海面波浪和风-海进行连续测量的基础上，求出粗糙度参数（Z_O）和摩擦系数（C_D）的平均风速分布，并考虑了与有效波高（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）与波龄（C_P/u*）之间的关系，以及表示海面状况的无量纲粗糙度参数（u*^2/σ_P）与摩擦阻力系数（C_D）之间的关系。此外，对湍流特性中的湍流强度和频谱进行了前人的研究，并进行了比较和检验。利用海洋技术综合研究所（国土交通省）在大井河口近海250米处进行了观测。风速测量进行， ...更多信息 d在杆上安装八个多点风速计的传感器，每隔0.5- 1.5米测量一次。此外，还附接并进行超声波水位计、精密压力计、温度计和超声波风速计的同时测量。采样时间为5 Hz，一次测量数据数为16384。粗糙度参数Z_0随标准风速V_0<10>的增大而增大，且在V_0<10>&gt; 8 m时增大幅度较大。在该2.4m/s的测量范围内，设定为0.00023&lt;Z 0 &lt;0.034。其次，要求作为卡门常数k=0.4的摩擦系数（C_D）随着标准风速（V_<10>）变大而线性增加，并且在该测量风速范围内将其设定为0.0014&lt;C_D&lt;0.0049。在0.8-1.2m范围内，摩擦系数C_D随有效波高H_&lt;1β&gt;的增加呈指数增加，摩擦系数C_D随粗糙度Z_0的增加呈指数增加。这与户田和古贺（1986）提出的无因次粗糙度参数（gZ_0/u*^2）与波龄（C_P/u*）之间的关系，在大波龄的波浪充分发展的范围内的公式基本一致。在摩擦阻力系数（C_D）与无量纲参数（u*^2/Δ σ_p）的关系中，u*^2/Δ σ_P的增大也使C_D增大。我正在做一个无量纲风速谱成为一个值比较接近日野的频谱形式达文波特的频谱形式，并在低频侧的频谱峰值附近。然而，在高频侧产生了比Davenport、Hino以及Ochi和Shin的频谱形式更大衰减的结果。少

项目成果

高橋琢磨, 田中博通: "海上風の乱流特性とべき指数について"土木学会中部支部 研究発表会講演概要集. 125-126 (2002)

Takuma Takahashi、Hiromichi Tanaka：“关于海风的湍流特性和功率指数”日本土木工程师学会中部分会研究报告摘要125-126（2002）。

Takahashi, T. and H, Tanaka.: "About the turbulent characteristic of the sea-wind and index distribution"Proceedings of research presentation meetin lecture outlines, JSCE of Chubu branch. 125-126 (2002)

Takahashi, T. 和 H, Tanaka.：“关于海风的湍流特性和指数分布”，JSCE 中部分部讲座大纲中的研究报告会议记录。

田中博通: "海上風の乱流特性と浮体まわりの流れの数値シミュレーション"海洋開発論文集. 第16巻. 233-237 (2000)

Hiromichi Tanaka：“海洋风和浮体周围流动的湍流特性的数值模拟”海洋发展论文第 16 卷 233-237（2000 年）。

野上,田中,川口,神: "海浜部における自然風の乱流特性について"土木学会中部支部研究発表会講演概要集. 699-700 (1999)

Nogami、Tanaka、Kawaguchi、Kami：“关于沿海地区自然风的湍流特性”日本土木工程师学会中部分会研究报告的讲座摘要 699-700 (1999)。

田中博通, 田中満, 南將人: "海上風の粗度パラメーターと摩擦係数について"海岸工学論文集. 48巻. 451-455 (2001)

Hiromichi Tanaka、Mitsuru Tanaka、Masato Minami：“关于海风的粗糙度参数和摩擦系数”沿海工程论文第 48 卷。451-455（2001）。