Hatter Department of Marine Technologies, University of Haifa, Haifa 3498838, Israel.
Sensors (Basel). 2023 Jan 26;23(3):1394. doi: 10.3390/s23031394.
The calculation of the drag force is a fundamental requirement in the design of any submerged system intended for marine exploration. The calculation can be performed by analytic analysis, numerical modeling, or by a direct calculation performed in a designated testing facility. However, for complex structures and especially those with a non-rigid design, the analytic and numerical analyses are not sufficiently accurate, while the direct calculation is a costly operation. In this paper, we propose a simple approach for how to calculate the drag coefficient in-situ. Aimed specifically at the complex case of elastic objects whose modeling via Computer-Aided Design (CAD) is challenging, our approach evaluates the relation between the object's speed at steady-state and its mass to extract the drag coefficient in any desired direction, the hydro-static force, and, when relevant, also the thruster's force. We demonstrate our approach for the special case of a highly complex elastic-shaped floater that profiles the water column. The analysis of two such floaters in two different sea environments shows accurate evaluation results and supports our claim for robustness. In particular, the simplicity of the approach makes it appealing for any arbitrary shaped object.
在设计任何用于海洋勘探的水下系统时，计算阻力都是基本要求。阻力的计算可以通过解析分析、数值建模或在指定的测试设施中直接计算来完成。然而，对于复杂的结构，特别是那些具有非刚性设计的结构，解析和数值分析不够准确，而直接计算则是一项昂贵的操作。在本文中，我们提出了一种简单的方法来现场计算阻力系数。我们的方法专门针对通过计算机辅助设计 (CAD) 建模具有挑战性的弹性物体的复杂情况，评估了物体在稳态下的速度与其质量之间的关系，以提取任何所需方向的阻力系数、静水压力，以及在相关情况下，还包括推进器的力。我们针对 profiling 水柱的高度复杂弹性形状浮标这一特殊情况展示了我们的方法。对两个不同海洋环境中的两个这样的浮标进行的分析显示了准确的评估结果，支持了我们对其稳健性的主张。特别是，该方法的简单性使其适用于任何任意形状的物体。
