{"title":"利用大涡流模拟和物理信息时空分解研究螺旋桨尾流演变","authors":"Zhan Zhang","doi":"10.21278/brod75102","DOIUrl":null,"url":null,"abstract":"A novel modal analysis methodology, denoted as the physics informed sparsity-promoting dynamic mode decomposition (pi-SPDMD) model, was introduced for the reduction and reconstruction analysis of intricate propeller wake flows, aiming to provide insight into the inherent flow structures spanning diverse temporal and spatial scales. Large-Eddy Simulation (LES) was employed to numerically model the wake dynamics of a four-bladed propeller, providing a comprehensive resolution from the proximate to the distant wake regions. The findings indicate that the pi-SPDMD model enhances the efficiency of the sparse-promoting algorithm, producing modes that gravitate towards stability, and the resulting decomposition maintains commendable physical fidelity. Integrating the results from the LES solution and the modal decomposition of pi-SPDMD, the tip vortex exhibits a uniform topological configuration with notable coherence in the proximate domain. In this region, the large-scale vortex is the dominant feature of the propeller wake, and there is a marked intermittency in the turbulence. In the mid-field, the tip vortex system transitions into fine-scale vortices, rapidly diminishing in coherence due to the onset of elliptic instability and subsequent secondary vortex generation. As the tip vortex structures related to physical quantities become fully discretized, the small-scale turbulent patterns quickly intermingle, leading to a more homogeneous distribution in the distant wake.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On the propeller wake evolution using large eddy simulations and physics-informed space-time decomposition\",\"authors\":\"Zhan Zhang\",\"doi\":\"10.21278/brod75102\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"A novel modal analysis methodology, denoted as the physics informed sparsity-promoting dynamic mode decomposition (pi-SPDMD) model, was introduced for the reduction and reconstruction analysis of intricate propeller wake flows, aiming to provide insight into the inherent flow structures spanning diverse temporal and spatial scales. Large-Eddy Simulation (LES) was employed to numerically model the wake dynamics of a four-bladed propeller, providing a comprehensive resolution from the proximate to the distant wake regions. The findings indicate that the pi-SPDMD model enhances the efficiency of the sparse-promoting algorithm, producing modes that gravitate towards stability, and the resulting decomposition maintains commendable physical fidelity. Integrating the results from the LES solution and the modal decomposition of pi-SPDMD, the tip vortex exhibits a uniform topological configuration with notable coherence in the proximate domain. In this region, the large-scale vortex is the dominant feature of the propeller wake, and there is a marked intermittency in the turbulence. In the mid-field, the tip vortex system transitions into fine-scale vortices, rapidly diminishing in coherence due to the onset of elliptic instability and subsequent secondary vortex generation. As the tip vortex structures related to physical quantities become fully discretized, the small-scale turbulent patterns quickly intermingle, leading to a more homogeneous distribution in the distant wake.\",\"PeriodicalId\":55594,\"journal\":{\"name\":\"Brodogradnja\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2024-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Brodogradnja\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://doi.org/10.21278/brod75102\",\"RegionNum\":4,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, MARINE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Brodogradnja","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.21278/brod75102","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MARINE","Score":null,"Total":0}
引用次数: 0
摘要
为对复杂的螺旋桨尾流进行还原和重构分析,引入了一种新的模态分析方法,称为物理信息稀疏性促进动态模态分解(pi-SPDMD)模型,旨在深入了解跨越不同时空尺度的固有流动结构。研究采用大型埃迪模拟(LES)对四叶螺旋桨的尾流动力学进行数值建模,提供了从近尾流区域到远尾流区域的全面分辨率。研究结果表明,pi-SPDMD 模型提高了稀疏促进算法的效率,产生了趋于稳定的模式,由此产生的分解保持了值得称道的物理保真度。综合 LES 解算结果和 pi-SPDMD 的模态分解结果,尖端漩涡呈现出均匀的拓扑结构,在近域具有显著的一致性。在该区域,大尺度涡是螺旋桨尾流的主要特征,湍流具有明显的间歇性。在中场,尖端涡旋系统过渡到细尺度涡旋,由于椭圆不稳定性的出现和随后次级涡旋的产生,相干性迅速减弱。随着与物理量相关的尖端涡旋结构完全离散化,小尺度湍流模式迅速交融,导致远处尾流的分布更加均匀。
On the propeller wake evolution using large eddy simulations and physics-informed space-time decomposition
A novel modal analysis methodology, denoted as the physics informed sparsity-promoting dynamic mode decomposition (pi-SPDMD) model, was introduced for the reduction and reconstruction analysis of intricate propeller wake flows, aiming to provide insight into the inherent flow structures spanning diverse temporal and spatial scales. Large-Eddy Simulation (LES) was employed to numerically model the wake dynamics of a four-bladed propeller, providing a comprehensive resolution from the proximate to the distant wake regions. The findings indicate that the pi-SPDMD model enhances the efficiency of the sparse-promoting algorithm, producing modes that gravitate towards stability, and the resulting decomposition maintains commendable physical fidelity. Integrating the results from the LES solution and the modal decomposition of pi-SPDMD, the tip vortex exhibits a uniform topological configuration with notable coherence in the proximate domain. In this region, the large-scale vortex is the dominant feature of the propeller wake, and there is a marked intermittency in the turbulence. In the mid-field, the tip vortex system transitions into fine-scale vortices, rapidly diminishing in coherence due to the onset of elliptic instability and subsequent secondary vortex generation. As the tip vortex structures related to physical quantities become fully discretized, the small-scale turbulent patterns quickly intermingle, leading to a more homogeneous distribution in the distant wake.
期刊介绍:
The journal is devoted to multidisciplinary researches in the fields of theoretical and experimental naval architecture and oceanology as well as to challenging problems in shipbuilding as well shipping, offshore and related shipbuilding industries worldwide. The aim of the journal is to integrate technical interests in shipbuilding, ocean engineering, sea and ocean shipping, inland navigation and intermodal transportation as well as environmental issues, overall safety, objects for wind, marine and hydrokinetic renewable energy production and sustainable transportation development at seas, oceans and inland waterways in relations to shipbuilding and naval architecture. The journal focuses on hydrodynamics, structures, reliability, materials, construction, design, optimization, production engineering, building and organization of building, project management, repair and maintenance planning, information systems in shipyards, quality assurance as well as outfitting, powering, autonomous marine vehicles, power plants and equipment onboard. Brodogradnja publishes original scientific papers, review papers, preliminary communications and important professional papers relevant in engineering and technology.