Investigation of time varying hydrodynamic added mass

当一个物体在水中移动时，一定体积的水会随着物体移动并影响系统的动力学。身体周围增加的流体被称为“附加质量”。当一个物体进入和离开水，发射和回收时，物体周围的流体量随着时间的变化而变化，增加的质量的变化导致高度可变的力，称为“砰”的一声。在传统的流体动力学代码或建模技术中没有考虑砰击现象。砰击的拟议调查，一个随时间变化的附加质量项目，汇集了动态系统分析有限公司（DSA）和卡尔顿大学的Rishad Irani博士。DSA的软件ProteusDS正在积极开发中，目前已被近20个商业组织和10多个学术组织使用。**DSA软件用于对系泊系统、船舶、起重机以及海上发射和回收操作进行数字建模。** ProteusDS中包含了流体动力学的一些方面，例如船舶运动和单个甲板组件上的流体动力学载荷。然而，在发射和回收过程中，对水动力砰击效应的研究有限。这些效应在大流速下尤其重要，** 无论是移动设备撞击水还是波浪撞击静态结构。DSA需要卡尔顿大学和Irani博士的协助，对发射和回收操作中随时间变化的附加质量和砰击效应进行调查、建模和验证。这项研究将有助于 ** 生产一个更新版本的ProteusDS，它包含了增加的质量现象，更适合 ** 在各种海况条件下进行发射和回收分析。砰击效应是极端海况条件下的一种重要的流体动力学效应，并且对于提高精度以满足国防，海洋可再生能源和海洋机器人领域的广泛应用需求具有重要意义。

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.