Numerical study for turbulent flow of drag and flow noise with wavy wall

In this paper, a numerical simulation of flow-induced noise by the low Mach number turbulent flow with a sinusoidal wavy wall was presented based on the unsteady incompressible Navier-Stokes equations and Lighthill’s acoustic analogy. Large eddy simulation (LES) was used to investigate the space-time flow field and the Smagorinsky sub-grid scale (SGS) model was introduced for turbulence model. Using Lighthill’s acoustics analogy, the flow field simulated by LES was taken as near-field sound sources and radiated sound from turbulent flow was computed by the Curle’s integral formulation under the low Mach number approximation. Both spanwise wavy wall and streamwise wavy wall with various wall wave amplitudes were discussed to investigate their effects on reducing the drag and flow noise. The relationship between flow noise and drag on the wavy wall is also studied.     

基于CFD的喷水推进器流道与喷口优化

为提高喷水推进器的水动力性能,对喷水推进器的流道与喷口进行了基于数值计算的优化研究.对一台喷水推进泵模型进行了敞水性能数值计算,验证了数值计算方法的准确性和有效性.对喷水推进器流道以及喷口进行参数化的几何重构和优化计算,考察流道与喷口参数对推进性能的影响.研究结果表明:在设计航速下,优化后的喷水推进器的转矩基本没变,推...     

基于模块化的小型喷水推进装置设计研究

针对艇用小型喷水推进装置,采用模块化产品的设计思路,从需求分析入手,初步形成满足设计要求的喷水推进模块总体方案。基于功能分解,将喷水推进模块划分为多个子功能模块,依据模块单元的功能属性和输入/输出开展结构与接口的详细设计,并注重模块的独立性和通用性设计。最后根据建立的评价体系,对功能、模块化和标准化等指标进行评价。基于本文思路设计的喷水推进装置应用于13 m工作艇并取得了良好的实船试航效果。装置的模块化程度高、安装维护便捷,对小型喷水推进装置的模块化设计有一定借鉴意义。     

喷水推进船舶二维控制手柄优化设计

本文针对喷水推进船舶常用的二维控制手柄功能开展优化设计。通过优化手柄单元的硬件结构和软件控制策略,实现了二维手柄在狭窄航道精确操舵、多工况推进和高速紧急停车等特殊航行场景下的控制功能。优化后的手柄控制系统经Simulink平台模拟仿真,结果满足预期的设计要求。该系统通过了实船功能验证,为后续大批量应用打下良好基础。