科考船艏部伴流特性及其流致声散射体输运机理研究

科考船艏部伴流作用下的海洋声散射体下洗输运对声学设备干扰问题多年来一直影响海洋声学探测和海洋认知的深度与广度，是一个有待深入研究并急需解决的重要问题。相关散射体伴流输运过程，是一种典型的既考虑连续相相间界面捕捉识别又包含非连续相-连续相间耦合作用的复杂多相流问题，包含：艏部伴流特性与绕流机理问题；船-伴流-散射体耦合作用散射体下洗特性与输运机制问题；下洗散射体对声学系统干扰削弱方法与削弱机理等待解决科学问题。本项目基于船艏伴流流动和散射体伴流输运过程中蕴含的关键科学问题，采用数值与试验结合的研究方法，应用PIV-CFD耦合技术获取艏部伴流特性并进行绕流机理分析。基于精细流场与散射体示踪试验数据建立散射体输运欧拉-拉格朗日耦合模拟方法，揭示散射体伴流特性与输运机制。结合散射体伴流输运机制和研究方法探究兼顾船型经济性与干扰削弱效果的解决方案，旨在为海洋声学探测、海洋深入认知提供技术保障。

The interference of ocean acoustic scatterers sweep down under the action of the bow wakes of marine scientific research vessels on acoustic equipment has been affecting the depth and breadth of ocean acoustic detection and ocean cognition for many years, and it is an important issue that needs to be studied in-depth and needs to be solved urgently. The associated scatterer sweep down process is a typical complex multiphase flow problem that not only considers the continuous phase interface capture and identification but also pays attention to the discrete phase-continuous phase coupling, including the characteristics of the flow field around the bow of a scientific research vessel and the related flow mechanism problems; The sweep down characteristics and transport mechanism of the scatterer under the coupling effect of ship-water-scatterer; The method and mechanism of attenuating the interference of scatterers sweep down to the acoustic system.. In order to solve the problem of the acoustic detection interference of the scatterer sweeping down on the scientific research vessel, this project intends to apply a method combining numerical and experimental research. Firstly, the particle image velocimetry (PIV) and computational fluid dynamics (CFD) techniques are applied to explore the characteristics of the flow field around the bow of a scientific research vessel and reveal the flow mechanism. On the basis of the current Euler simulation method, a Lagrangian discrete phase model is introduced, and the Euler-Lagrange coupling simulation method is established based on the scatterer tracer experimental data. And the properties and transport mechanisms of discrete acoustic scatterer sweep down are explored. In the end, the simulation method of scatterer transport is used to simulate and evaluate a series of optimization schemes, and a scheme for considering both resistance performance and inhibition effect is established, providing technical support and design reference for the interference reduction of scatterer transport to the acoustic measurement system.. The purpose of this project is to provide technical support for the improvement of the acoustic detection accuracy of the scientific research vessel. And aims to provide technical support for marine acoustic detection and a deep understanding of the ocean.