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Overview of Research Progress on numerical simulation methods for Turbulent Flows Around Underwater Vehicles

Journal of Marine Science and Application 2024年第1期23卷 1-22页

作者： Kangjian He Zhi Pan Weiwen Zhao Jianhua Wang Decheng Wan Computational Marine Hydrodynamics Lab (CMHL) School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China Wuhan Second Ship Design and Research Institute Wuhan 430205 China

In this paper, we present an overview of numerical simulation methods for the flow around typical underwater vehicles at high Reynolds numbers, which highlights the dominant flow structures in different regions of interest. This overview covers the forebody, midbody, stern, wake region, and appendages and summarizes flow phenomena, including laminar-to-turbulent transition, turbulent boundary layers, flow under the influence of curvatures, wake interactions, and all associated complex vortex structures. Furthermore, the current issues and challenges of capturing these flow structures are addressed. This overview provides a deep insight into the use of numerical simulation methods, including the Reynolds-averaged Navier–Stokes (RANS) method, large eddy simulation (LES) method, and the hybrid RANS/LES method, and evaluates their applicability in capturing detailed flow features.

关键词： numerical simulation methods Underwater vehicles Boundary layer transition Turbulent boundary layer Wake Appendages

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Modeling and performance analysis of phase change materials in advanced thermal energy storage systems: A comprehensive review

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JOURNAL OF ENERGY STORAGE 2025年 121卷

作者： Abdellatif, Houssam Eddine Belaadi, Ahmed Arshad, Adeel Bourchak, Mostefa Univ 20 Aout 1955 Fac Technol Dept Genie Mecan Skikda Algeria Aston Univ Coll Engn & Phys Sci Dept Mechatron & Biomed Engn Birmingham B4 7ET England King Abdulaziz Univ Aerosp Engn Dept Jeddah Saudi Arabia

Phase change materials (PCMs) are crucial for efficient energy storage, yet their inherent challenges include low thermal conductivity, limited latent heat capacity, and potential leakage. This review comprehensively examines advanced thermal energy storage (TES), focusing on latent and hybrid systems. Innovative methods to enhance PCM performance are explored, such as incorporating fins, nanoparticles, porous matrices, multiple PCMs, encapsulation, and stabilization techniques. Various numerical simulation methods (Enthalpy, Heat Capacity, Finite Difference, etc.) are detailed for precise modeling of thermal storage systems. The study investigates diverse composite PCMs (NePCM, hybrid, encapsulated, porous), supported by tables summarizing studies on shell-and-tube heat exchanger modifications, hybrid tank investigations, and fin geometries. By critically analyzing recent advancements, this review provides new insights into the effectiveness of enhancement techniques and the role of numerical modeling in optimizing TES performance. Unlike previous reviews, this work integrates a comparative evaluation of hybrid TES systems, highlighting their advantages over conventional latent and sensible storage methods. Additionally, it bridges the gap between experimental studies and numerical modeling, providing engineers with practical guidelines for optimizing PCM-based TES designs. This synthesis of data is essential for researchers and engineers in sustainable energy systems. Emphasizing PCM's pivotal role in energy efficiency, the study underscores the urgent need for innovative solutions. Future research should focus on enhancing thermal conductivity, minimizing leakage, and improving long-term stability to maximize the practicality and efficiency of PCM-based TES systems.

关键词： Phase change materials (PCMs) Thermal energy storage (TES) technologies numerical simulation methods PCMs performance enhancement methods Sustainable energy systems Nanoparticles in PCMs Porous matrices Encapsulation techniques Shape stabilization

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水下航行体湍流数值模拟方法研究进展综述

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哈尔滨工程大学学报（英文版） 2024年第1期23卷 1-22页

作者：和康健潘治赵伟文王建华万德成 Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Wuhan Second Ship Design and Research Institute Wuhan 430205China

In this paper,we present an overview of numerical simulation methods for the flow around typical underwater vehicles at high Reynolds numbers,which highlights the dominant flow structures in different regions of *** overview covers the forebody,midbody,stern,wake region,and appendages and summarizes flow phenomena,including laminar-to-turbulent transition,turbulent boundary layers,flow under the influence of curvatures,wake interactions,and all associated complex vortex ***,the current issues and challenges of capturing these flow structures are *** overview provides a deep insight into the use of numerical simulation methods,including the Reynolds-averaged Navier–Stokes(RANS)method,large eddy simulation(LES)method,and the hybrid RANS/LES method,and evaluates their applicability in capturing detailed flow features.

关键词： numerical simulation methods Underwater vehicles Boundary layer transition Turbulent boundary layer Wake Appendages

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numerical simulations of forced convection across a single tube to evaluate applicability of the DNS, LES and RSM methods

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APPLIED THERMAL ENGINEERING 2017年 123卷 123-130页

作者： Zhou, Bonan Yang, Mo Li, Zheng Wang, Zhiyun Zhang, Yuwen Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Univ Missouri Dept Mech & Aerosp Engn Columbia MO 65211 USA

Forced convection across a single tube was investigated numerically for various Reynolds numbers using various numerical models to identify suitable ranges for each model. Direct numerical simulations (DNS), large eddy simulations (LES), and a Reynolds averaged model using the Reynolds stress model (RSM) were compared with experimental date. The calculations used unsteady two-dimensional models with air as the working fluid. For the mesh used here, for Re < 10,000, the DNS method gave good results. For 10,000 < Re < 100,000, the LES is preferred while for Re > 100,000, the RSM is better. Nonlinear phenomena were found for various Reynolds numbers. For Re < 100, the average Nusselt number did not change with time while for 100 < Re < 1000, the average Nusselt number oscillated with time. The local Nusselt numbers along the entire tube are also discussed. (C) 2017 Published by Elsevier Ltd.

关键词： Forced convection Flow across a single tube numerical simulation methods DNS LES RSM

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Viscous-plastic sea ice dynamics with the EVP model: Linearization issues

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JOURNAL OF COMPUTATIONAL PHYSICS 2001年第1期170卷 18-38页

作者： Hunke, EC Los Alamos Natl Lab Div Theoret Grp Fluid Dynam T 3 Los Alamos NM 87545 USA

Behavior of the elastic-viscous-plastic (EVP) model for sea ice dynamics is explored, with particular attention to a necessary numerical Linearization of the internal ice stress term in the momentum equation. Improvements to both the mathematical and numerical formulations of the model have moderated the impact of linearizing the stress term;simulations with the original EVP formulation and the improved version are used to explain the consequences of using different numerical approaches. In particular,, we discuss the model behavior in two regimes, low ice concentration such as occurs in the marginal ice zone, and very high ice concentration, where the ice is nearly rigid. Most of these results are highly relevant to the viscous-plastic (VP) ice dynamics model on which the EVP model is based. We provide examples of certain pathologies that the VP model and its numerical formulations exhibit at steady state. (C) 2001 Academic Press.

关键词： sea ice visco-plasticity constitutive equations numerical simulation methods

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Shape-Programming in Hyperelasticity Through Differential Growth

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APPLIED MATHEMATICS AND OPTIMIZATION 2024年第2期89卷 49-49页

作者： Ortigosa-Martinez, Rogelio Martinez-Frutos, Jesus Mora-Corral, Carlos Pedregal, Pablo Periago, Francisco Tech Univ Cartagena Dept Appl Math & Stat Campus Muralla Mar Cartagena 30202 Murcia Spain Tech Univ Cartagena Multiphys Simulat & Optimizat Lab Campus Muralla Mar Cartagena 30202 Murcia Spain Univ Autonoma Madrid Dept Math Madrid 28049 Spain Inst Ciencias Matemat CSIC UAM UC3M UCM Madrid 28049 Spain Univ Castilla La Mancha Dept Math INEI Camilo Jose Cela2 Ciudad Real 13071 Castilla La Man Spain

This paper is concerned with the growth-driven shape-programming problem, which involves determining a growth tensor that can produce a deformation on a hyperelastic body reaching a given target shape. We consider the two cases of globally compatible growth, where the growth tensor is a deformation gradient over the undeformed domain, and the incompatible one, which discards such hypothesis. We formulate the problem within the framework of optimal control theory in hyperelasticity. The Hausdorff distance is used to quantify dissimilarities between shapes;the complexity of the actuation is incorporated in the cost functional as well. Boundary conditions and external loads are allowed in the state law, thus extending previous works where the stress-free hypothesis turns out to be essential. A rigorous mathematical analysis is then carried out to prove the well-posedness of the problem. The numerical approximation is performed using gradient-based optimisation algorithms. Our main goal in this part is to show the possibility to apply inverse techniques for the numerical approximation of this problem, which allows us to address more generic situations than those covered by analytical approaches. Several numerical experiments for beam-like and shell-type geometries illustrate the performance of the proposed numerical scheme.

关键词： Soft robotics Differential growth Hyperelasticity Shape-programming Optimal control numerical simulation methods

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Comparison Between Different Finite Element Analyses of Unbonded Flexible Pipe via Different Modeling Patterns

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Journal of Shanghai Jiaotong university(Science) 2019年第3期24卷 357-363页

作者： PANG Guoliang CHEN Chaohe SHEN Yijun LIU Fuyong Naval Architecture and Ocean Engineering R&D Center of Guangdong Province South China University of Technology

Three kinds of models based on the same flexible pipe with 8 layers have been separately created to investigate the effects of different modeling approaches on numerical simulation results of finite element(FE)models for unbonded flexible *** the mechanical property of the unbonded flexible pipe under tension,torsion and bending load has been analyzed and compared via ABAQUS software on the basis of three created *** research shows that different modeling methods of flexible pipes make a great difference in the ***,modeling simplifications of the carcass and pressure armor have a great impact on the accuracy of the *** 3,in which the carcass is simulated by spiral isot ropic shell and other layers are Simula ted by solid element,possesses good adaptability,which has been proved by comparing the experiment data and other *** paper can offer a reference for the FE modeling methods,selection and mechanical property analysis of unbonded flexible pipe.

关键词： unbonded flexible pipe numerical simulation methods finite element(FE) analysis

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Power Semiconductor Converter Optimization of Electric Drive 17

Power Semiconductor Converter Optimization of Electric Drive

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17th International Ural Conference on Alternating Current Electric Drives (ACED)

作者： Tsirkunenko, Anatoly T. Gryzlov, Artyom A. Bukhanov, Sergey S. RiK Energo Lld Ekaterinburg Russia

ISBN: (纸本)9781538624227

This paper presents the optimization of power circuits of multiphase semiconductor converters which powered synchronous reluctance electric drives. In the general case, currents leak through power circuits which form is different from a sinusoidal one. By way of the optimization criterion of main-circuit connections, the condition was assumed to provide the maximum torque created by the electric drive. The second stage presents an algorithm for numerical optimization of the phase current form in multiphase synchronous reluctance electric drives. The dependence of the pulsations of the electromagnetic torque as a function of the number of phases in an electric machine is obtained. It is established that an increase in the number of phases greater than 6 does not significantly reduce the pulsations of the electromagnetic torque. A further increase in the number of phases leads to an increase in the cost of the semiconductor converter.

关键词： semiconductor converter electric losses multiphase circuit numerical simulation methods

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Interconnecting Subsea DC Collection Systems into a High Reliability DC Grid

Interconnecting Subsea DC Collection Systems into a High Rel...

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5th IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT Europe)

作者： Zhang, Huibin Jovcic, Dragan Univ Aberdeen Sch Engn Aberdeen Scotland

ISBN: (纸本)9781479977208

This paper presents a subsea DC collection grid with robust control and protection scheme and flexible expansion capability. By virtue of the DC/DC converter, different sections of the subsea grid are functionally interconnected and in the meantime decoupled in the event of DC faults. The faults are selectively isolated and system recovery from the faulty DC intertie branch is achieved by a coordinated operation on DCDC converters and DC disconnectors (or standard AC circuit breakers). A test system is presented which consists of two 100MW renewable energy sources and DC collection/transmission grids. The simulation results confirm the N-1 security of the presented topology and good control performance over DC faults.

关键词： Converter modeling High Frequency Components DC Power Systems DC power transmission DC-DC power conversion numerical simulation methods

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High-Power High-Frequency Converter Modelling Using Dommel's and Runge-Kutta methods in ABC and DQ frame

High-Power High-Frequency Converter Modelling Using Dommel's...

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IEEE PES General Meeting

作者： Lin, Wei-Xing Jovcic, Dragan Univ Aberdeen Sch Engn Aberdeen Scotland

ISBN: (纸本)9781479964154

As the future DC grids will involve numerous converter systems, the accuracy and speed of their modeling becomes of high importance. This paper develops and compares four average models for high frequency converters like DC/DC or DC hubs: the average model in the ABC frame using Dommel's method (Model 1), the average model in the dq frame using Dommel's method (Model 2), the average model in the ABC frame using Runge-Kutta method (Model 3) and the average model in the dq frame using Runge-Kutta method (Model 4). Schematics and principles of the numerical algorithms for the four models are presented. Detailed switching model of a 500MW, 2kHz, +/- 200kV/+/- 400kV DC/DC converter is taken as benchmark for comparing the four average models. It is found that Model2 is numerically unstable. Model 1 and Model3 need the same small solution time step as the detailed switching model to give accurate results. Model 4 is the recommended average model for high frequency (1-3kHz) converter. It gives accurate result as the detailed switching model at the benefit of 100 times faster simulation speed.

关键词： Converter modeling High Frequency Components DC Power Systems DC power transmission DC-DC power conversion numerical simulation methods

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