Investigation of time varying hydrodynamic added mass

当物体在水中运动时，一定体积的水将与物体一起运动，并影响系统的动力学。在身体周围增加的液体被称为“附加质量”。在物体进出水、发射和回收的过程中，物体周围的流体量随时间变化，附加质量的变化会产生非常不同的力，也就是“砰”的一声。传统的流体力学代码或建模技术没有**考虑到砰砰的现象。**建议的砰击调查是一个时变的附加质量项目，将动力系统分析有限公司(DSA)和卡尔顿大学的里沙德·伊拉尼博士结合在一起。DSA的软件ProteusDS正在积极**开发中，目前被近20个商业组织和10多个学术组织使用。**DSA软件用于对系泊、船舶、起重机以及海上下水和回收作业进行数值模拟。**在ProteusDS中融入了一些水动力学方面的内容，例如船舶运动和水动力**单个甲板部件上的载荷。然而，对发射和回收过程中的流体动力学撞击效应的调查有限。这些效应在大速度时尤其重要，**无论是移动设备撞击水面还是波浪撞击静态结构。**DSA需要卡尔顿大学和伊拉尼博士的协助，以进行调查、建模和验证**发射和回收操作的时变附加质量和撞击效应。这项研究将帮助**产生一个更新版本的ProteusDS，它包含了增加的质量现象，更适合**在广泛的海况条件下进行发射和回收分析。撞击效应是极端海况下的一种重要的水动力效应，因此需要提高精度，以满足国防、海洋可再生能源和海洋机器人领域广泛应用的需要。

As an object moves through water, a volume of water will move with the body and influence the dynamics of**the systems. The added fluid around the body is referred to as "added mass". As a body transfers into and out of**the water, launch and recovery, the amount of fluid around the body varies as a function of time and the change**in added mass causes highly variable forces, referred to as "slamming". The slamming phenomena is not**accounted in traditional hydrodynamic codes or modelling techniques.**The proposed investigation of slamming, a time varying added mass project, brings together Dynamic Systems**Analysis Ltd. (DSA) and Dr. Rishad Irani of Carleton University. DSA's software, ProteusDS, is under active**development and is currently used by nearly 20 commercial and more than 10 academic organizations. The**DSA software is used to numerically model moorings, ships, cranes, and marine launch and recovery operation.**Some aspects of hydrodynamics are incorporated in ProteusDS such as the vessel motion and hydrodynamic**loading on the individual deck components. However, there has been limited investigation into hydrodynamic**slamming effects during launch and recovery. These effects are particularly important during large velocities,**whether moving equipment impacts the water or if a wave impacts a static structure.**DSA requires the assistance of Carleton University and Dr. Irani to conduct an investigate, model and validate**the time varying added mass and slamming effects for launch and recovery operations. The research will help**produce an updated version of ProteusDS which incorporate the added mass phenomena and is more suitable**for launch and recovery analysis over a wide range of sea state conditions. Slamming effects are an important**hydrodynamic effect in extreme sea state conditions and there are implications for improved accuracy to meet**the needs of a wide range of applications in the defense, marine renewables, and ocean robotics sectors.