Day 1 Tue, October 26, 2021最新文献_第10页

The Impact of Sweep Angle on Stepped Planing Hull Performance 后掠角对阶梯式船体性能的影响

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-010

Nicholas Husser, S. Brizzolara

引用次数: 2

Vertical Wedge Water-Entry through Experiments and Simulation to Explore Three-Dimensional Hydrodynamic Flow Characteristic 通过实验和模拟探讨垂直楔形进水的三维水动力流动特性

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-004

Arman Bhardwaj, M. Javaherian, Nicholas Husser

引用次数: 0

The Wave System of the Sydney Harbor RiverCat Ferry 悉尼港河猫渡轮的波浪系统

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-007

L. Doctors

引用次数: 0

The Impacts of Model Uncertainty on RANS CFD Simulations of a High-Speed Craft 模型不确定性对某高速飞行器RANS CFD仿真的影响

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-026

Joseph Messler, Nicholas Husser, S. Brizzolara

{"title":"The Impacts of Model Uncertainty on RANS CFD Simulations of a High-Speed Craft","authors":"Joseph Messler, Nicholas Husser, S. Brizzolara","doi":"10.5957/fast-2021-026","DOIUrl":"https://doi.org/10.5957/fast-2021-026","url":null,"abstract":"Computational scientists frequently publish papers discussing various sources of uncertainty in numerical methods for computational fluid dynamics. The frequently discussed sources of uncertainty are round off error, discretization error, iterative error, and mathematical model uncertainty (i.e. uncertainty in turbulence modeling). While all of these sources of uncertainty are real and impact the results of a simulation, the authors have found through experience that the most critical element to achieving accurate simulation results for high-speed craft is the generation of a high quality mesh on which the numerical methods are solved. There are, in general, two requirements for a high quality mesh; refinement regions must be applied in regions where the physics of the flow are most significant, and the three dimensional model of the hull form must be appropriately defined and fair. The latter appears to be a major contributing factor to uncertainty in CFD simulations that is not often discussed in the literature. Further, in practice there are numerous sources of geometric uncertainty between a prescribed CAD geometry and physically constructed model. In this paper, simulations are performed on two models of GPPH, with and without an edge radius on the transom to evaluate the impact of including fine geometric details (like tooling radii) in a RANS CFD model. The results of the simulations show that the inclusion of the rounded edge leads to large simulation errors in resistance and running attitude. This work has concluded that inclusion of fine geometric details in a planing hull CFD model is not beneficial to the overall accuracy of the simulations relative to necessary design accuracy.","PeriodicalId":11146,"journal":{"name":"Day 1 Tue, October 26, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90880381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Hydrodynamics of High-Speed Planing Craft: Savitsky Method and 2D+t Approach 高速刨床流体动力学:Savitsky方法和2D+t方法

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-024

M. Javaherian, R. Royce, R. Datla, Christine M. Gilbert

引用次数: 0

Using VOF Slip Velocity to Improve Productivity of Planing Hull CFD Simulations 利用VOF滑移速度提高船体规划CFD仿真效率

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-013

M. Wheeler, Philip Ryan, Flavio Cimolin, A. Gunderson, J. Scherer

{"title":"Using VOF Slip Velocity to Improve Productivity of Planing Hull CFD Simulations","authors":"M. Wheeler, Philip Ryan, Flavio Cimolin, A. Gunderson, J. Scherer","doi":"10.5957/fast-2021-013","DOIUrl":"https://doi.org/10.5957/fast-2021-013","url":null,"abstract":"Use of Computational fluid dynamics (CFD) tools is becoming common practice in the analysis of high speed craft. These numerical tools are of great value, since they can provide high-fidelity insight into performance of various designs by modelling non-linear effects due to viscous forces and turbulence. However, CFD tools are often seen as computationally expensive and prohibitive in a design environment. One of the main issues that impacts the use of CFD tools is numerical ventilation, when air is artificially entrained beneath the hull while using the Volume of Fluid (VOF) scheme to model the free surface. To overcome this issue, traditionally, very fine grids are requested near the surface of the hull to resolve the flow. In this paper, it will be illustrated how the use of an algebraic VOF slip velocity, in conjunction with a tight overset model and adaptive mesh refinement prevent the issue of numerical ventilation while simultaneously using a more computationally efficient mesh that produces accurate results in calm water resistance calculations. A verification and validation process comparing the VOF slip velocity method against experimental data for a known hull was conducted. Computational cost and accuracy associated with VOF slip velocity is discussed. The methodology is then applied to a stepped hull and comparisons between towing tank experiments and simulation results are looked at.","PeriodicalId":11146,"journal":{"name":"Day 1 Tue, October 26, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76986370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Modeling Vertical Planing Boat Motions using a Neural-Corrector Method 基于神经校正方法的垂直刨船运动建模

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-014

K. Marlantes, K. Maki

{"title":"Modeling Vertical Planing Boat Motions using a Neural-Corrector Method","authors":"K. Marlantes, K. Maki","doi":"10.5957/fast-2021-014","DOIUrl":"https://doi.org/10.5957/fast-2021-014","url":null,"abstract":"The dynamics of high-speed planing craft are complex and nonlinear. Standard analysis methods, such as linear potential theory, while convenient and computationally efficient, are often not suitable for use in predicting the dynamics of such craft because physical realities or design requirements invalidate the inherent assumptions. High-fidelity methods, such as state-of-the-art CFD simulations, can offer accurate solutions, but these methods are limited by computational cost and numerical sensitivity. In addition, these methods are not efficient enough to provide rapid evaluation of operability, i.e. simulations over a wide range of operating conditions and environments. This leaves few practical analysis options for small, high-speed craft designers who need to perform such predictions. In this paper, the authors present a neural-corrector method that shows promise in providing efficient predictions of vertical planing craft motions. The method retains higher-order terms typically truncated in the classical coupled 2-DOF system of ordinary differential equations using Long Short-Term Memory (LSTM) recurrent neural networks. In this manner, the robust solution provided by the linear model is retained, and the LSTM networks act as higher-order correctors. The correctors primarily regress on the solution, affording familiar numerical integration techniques for systems of nonlinear differential equations. Training and validation results from the method are compared to nonlinear simulations of 2-DOF motion of a Generic Prismatic Planing Hull (GPPH) at forward speed in head seas, with time histories given for both regular and irregular waves.","PeriodicalId":11146,"journal":{"name":"Day 1 Tue, October 26, 2021","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75037039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Classification of Slamming Events in Irregular Waves Measured through Tow Tank Experiments 拖曳槽试验测量的不规则波中撞击事件的分类

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-001

Mark L. Shepheard, Carolyn Q. Judge, Christine M. Gilbert

引用次数: 0

The Sea Striker: Foilers are back in the game 海前锋:剧透又回来了

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-025

Alexis Blasselle, C. Bouvier, Gaetan Calvar, Louis Floch

引用次数: 0

What is the True Potential of Dynaplane Technology? Dynaplane技术的真正潜力是什么?

Day 1 Tue, October 26, 2021 Pub Date : 2021-10-18 DOI: 10.5957/fast-2021-009

N. Parkyn

引用次数: 0