RANS simulation of interceptor effect on hydrodynamic coefficients of longitudinal equations of motion of planing catamarans
RANS simulation of interceptor effect on hydrodynamic coefficients of longitudinal equations of motion of planing catamarans
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DOI：
10.1007/s40430-014-0256-6
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发表时间：
2015-07
影响因子：
2.2
通讯作者：
A. Najafi;S. Alimirzazadeh;M. Seif
中科院分区：
文献类型：
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作者：
A. Najafi;S. Alimirzazadeh;M. Seif
了解和研究高速船的动力学、静水中的纵向动力不稳定性和波浪中的行为具有重要意义。运动方程系数的确定有助于分析这类容器的动力特性和影响其动力稳定性的因素。因此，它可以用于控制船舶的不稳定性。本研究的主要目的是利用计算流体力学（CFD）确定双体船的纵向运动系数，并评估拦截器对双体船纵向运动系数的影响，该方法在高速船舶运动控制中得到广泛应用。采用RANS和连续性控制方程对受迫的纯升沉和俯仰运动进行了数值模拟，确定了水动力系数。使用实验方法确定这些系数相对昂贵，并且需要精确的实验室设备；因此，利用数值方法开发虚拟实验室是非常有效的。首先采用CFD模拟方法获得了某高速艇的水动力系数，然后通过Troesch （J Ship Res 36(4): 317-331, 1992）试验验证了数值结果。在确定了带截流器和不带截流器的双体船的水动力系数后，将评估截流器对双体船水动力系数的影响。结果表明，大多数系数与频率无关，特别是在高频处。此外，除少数情况外，截流器对不同频率水动力系数的影响可以忽略不计。
Understanding and investigation of a high-speed craft dynamics, their longitudinal dynamic instabilities in calm water and behavior in waves are of a great importance. Determination of motion equation coefficients will help to analyze the dynamics of these kinds of vessels and the factors affecting their dynamic stabilities. Therefore, it could be useful in controlling the vessel instabilities. The main purpose of this research is to determine the coefficients of longitudinal motions of a planing catamaran using computational fluid dynamics (CFD) and evaluating the interceptor effect on hydrodynamic coefficients of that, which is widely utilized in controlling the motions of a high-speed craft. The forced pure heave and pitch motions are simulated in a numerical domain with RANS and continuity governing equations to determine the hydrodynamic coefficients. Determination of these coefficients using experimental approaches is relatively expensive, and requires precise laboratory equipment; therefore, utilizing numerical methods and develop a virtual laboratory seem highly efficient. In the beginning, the hydrodynamic coefficients of a high-speed craft obtained using CFD simulation and then the numerical results were verified by Troesch (J Ship Res 36(4):317–331, 1992) experimental tests. At the following, after determination of hydrodynamic coefficients of a planing catamaran with and without Interceptor, the interceptor effects on its hydrodynamic coefficients will be evaluated. The results indicate that most of coefficients are frequency independent especially at high frequencies. Also, the interceptor effect on hydrodynamic coefficients in different frequencies is negligible except for a few cases.