Day 1 Wed, October 04, 2017最新文献

Statistical Perspectives on Some Problems Arising in Naval Engineering 船舶工程中若干问题的统计观点

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0047

Dylan Glotzer, V. Pipiras

引用次数: 0

Wavelet Transform as a Filtering Technique to Ship Motion Time Series 小波变换对船舶运动时间序列的滤波

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0028

Mariana Candella

引用次数: 0

Stochastic Inversion Framework to Monitor Evolving Mass Properties of a Ship at Sea during Arctic Operations 监测北极作业期间海上船舶质量特性变化的随机反演框架

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0036

Yolanda C. Lin, C. Earls

{"title":"Stochastic Inversion Framework to Monitor Evolving Mass Properties of a Ship at Sea during Arctic Operations","authors":"Yolanda C. Lin, C. Earls","doi":"10.5957/attc-2017-0036","DOIUrl":"https://doi.org/10.5957/attc-2017-0036","url":null,"abstract":"This work investigates the indirect monitoring of Arctic ice accretion on ship surfaces using a stochastic inversion framework. An accurate assessment of a ship’s mass properties during operation is an important concern for ships traveling in adverse conditions. Specifically, in the Arctic, the risk of ice accumulation on the topside of the ship is heightened. Within such contexts, the actual, or current, first and second moment properties of the vessel, including accumulated topside icing, become critical in the associated equations of motion for a given ship. By leveraging an existing on-board inertial measurement unit in conjunction with existing seakeeping software, the framework here recovers a posterior distribution of a single mass property. The inverse problem is demonstrated with two mass properties: the vertical center of gravity (a first moment mass property), and the roll gyradius (a second moment mass property).\u0000 The inversion scheme requires two main inputs: an observed ground truth for the roll period, and an associated signal-to-noise ratio for the roll period measurement. The framework applies a Markov chain Monte Carlo (MCMC) inversion scheme, implemented in Python, that leverages Standard Ship Motion Program (SMP95) software in order to build a posterior distribution. Experimental model results from Research Vessel (R/V) Melville – Model 5748 provide the necessary inputs to the inversion scheme. Six different configurations, including one case of no icing and five cases of topside icing, are investigated within the context of this framework at full-scale from model-scale in order to invert for the six respective roll gyradii and vertical center of gravities. Icing configurations include both asymmetric and symmetric ice accumulation under moderate to heavy icing conditions.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121379187","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

Using Hydrodynamic Testing to Assess the Performance of Five Fouling Control Coatings Immersed at Two Field Sites along the East Coast of Florida 在佛罗里达东海岸的两个油田进行了水动力测试，以评估五种污染控制涂层的性能

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0008

J. T. Hunsucker, H. Gardner, G. Swain

{"title":"Using Hydrodynamic Testing to Assess the Performance of Five Fouling Control Coatings Immersed at Two Field Sites along the East Coast of Florida","authors":"J. T. Hunsucker, H. Gardner, G. Swain","doi":"10.5957/attc-2017-0008","DOIUrl":"https://doi.org/10.5957/attc-2017-0008","url":null,"abstract":"Static immersion studies are commonly used to assess the performance of fouling control coatings. While these tests provide valuable data, it is also of importance to understand the drag forces associated with the accrued fouling communities and the velocities required for fouling removal. Combining the measurements of hydrodynamic testing with those from static immersion testing can help in predicting the performance of coatings prior to their consideration for use on Navy vessels. Replicates of five commercially available coatings (three fouling release coatings and two biocide based coatings) were deployed at two static immersion test sites located along the east coast of Florida (Port Canaveral and Sebastian Inlet). After four months of immersion, the panels were removed, photographed, subjected to known water velocities in a high-speed boat modified for hydrodynamic testing. Each panel was run at 5 m/s for 10 minutes, photographed, and then run at 10 m/s for 10 minutes. The drag forces were measured at speeds of 3, 6, 8.8 and 10 m/s for 1 minute each. Photographs taken before, during, and after hydrodynamic testing were also visually analyzed. After testing adhesion measurements were taken to determine the attachment strength of any hard fouling organisms which remained on the panels. The data collected from this series of tests, enabled the fouling control and fouling release properties of each coating to be characterized.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115136593","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: 0

Operational Experience With The New Harold E. Saunders Maneuvering And Seakeeping (MASK) Basin Directional Wavemaker 新型哈罗德·e·桑德斯机动和耐波性(MASK)盆地定向造波器的操作经验

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0033

J. Hoyt, Steven R. Turner, H. Moeller, S. Carpenter, Miguel R. Quintero

{"title":"Operational Experience With The New Harold E. Saunders Maneuvering And Seakeeping (MASK) Basin Directional Wavemaker","authors":"J. Hoyt, Steven R. Turner, H. Moeller, S. Carpenter, Miguel R. Quintero","doi":"10.5957/attc-2017-0033","DOIUrl":"https://doi.org/10.5957/attc-2017-0033","url":null,"abstract":"The Naval Surface Warfare Center, Carderock Division replaced their 21 pneumatic type wavemaker domes with a 216-paddle directional wavemaker in the fall of 2013. This wavemaker is capable of producing regular waves at oblique angles to the wave banks as well as long crested and short crested irregular model seas. Another powerful capability of the new system is the ability to preview the commanded waves in 3D virtual space on the computer screen. The new directional wavemaker facility has been in operation for four years. Mixtures of capabilities exceeding the original requirements as well as unforeseen problems were encountered. Based upon the operational experience gained in the last four years lessons learned are presented. Going from 21 domes to 216 individual paddles has adverse consequences on maintenance and reliability. That in and of itself is just a consequence of requiring a more complex machine to make more complex waves – not really good or bad. Despite the initial concerns this wavemaker has proven to be reliable, easily maintainable and when required, easily repairable.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125379231","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: 0

On Wave Field Reconstruction Based on a Single Probe Data in Long Crest Waves 基于长波峰单探头数据的波场重建

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0037

Sheguang Zhang, S. S. Lee, C. Kent

{"title":"On Wave Field Reconstruction Based on a Single Probe Data in Long Crest Waves","authors":"Sheguang Zhang, S. S. Lee, C. Kent","doi":"10.5957/attc-2017-0037","DOIUrl":"https://doi.org/10.5957/attc-2017-0037","url":null,"abstract":"The time history of wave elevations measured at a single wave probe in long crest waves is used to reconstruct the propagating wave field. The reconstruction follows the potential flow theory with linear or nonlinear free surface boundary conditions. The linear approach is used to verify the relation between the sample size of the probe data and the size of the valid reconstruction zone. It is also used to prescribe the initial conditions of the reconstructed wave system on a 2D spatial domain in terms of the free surface elevation and the velocity potential at calm water surface z=0 and t=0. The nonlinear approach is based on a HighOrder-Spectral (HOS) method which takes the initial conditions generated by the linear approach and propagates the wave system in time and space in a linear or nonlinear fashion. The numerically reconstructed waves using both approaches are compared with the measured waves at location(s) of (a) a single probe and (b) multiple probes aligned with the direction of the wave propagation. The relation between the probe location and the reconstruction point is investigated. The difference between the linear and the nonlinear approach up to the 3rd order is also investigated. The results show that for a wave system with moderate spectral steepness (Hs/λm= 0.03), the wave elevation calculated at a point within the valid reconstruction zone by either the linear wave theory or the 1st order HOS method matches well with the measurement.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128384298","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: 0

New Methodology in Analysis of Physical Properties and Roll Decay with Uncertainty Estimates for Surface-Ship Model Experiments 基于不确定估计的水面舰船模型实验物理特性和横摇衰减分析新方法

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0020

J. Park, C. Turner, M. Melendez

{"title":"New Methodology in Analysis of Physical Properties and Roll Decay with Uncertainty Estimates for Surface-Ship Model Experiments","authors":"J. Park, C. Turner, M. Melendez","doi":"10.5957/attc-2017-0020","DOIUrl":"https://doi.org/10.5957/attc-2017-0020","url":null,"abstract":"Physical properties and roll decay of David Taylor Model Basin (DTMB) Model 5720, a 23rd scale free running model of the research vessel (R/V) Melville, are documented with uncertainty estimates. Properties include mass, vertical center of gravity (VCG), longitudinal center of gravity (LCG), and transverse center of gravity (TCG), and moments of inertia (MOI) for roll and pitch, transverse metacentric height (GMT), and natural roll period, Tn. Previous analysis has been expanded with additional details and uncertainty estimates. Results are based on measurements with the latest technology. The significant results for model properties are as follows: length 3.3652 ±0.0010 m (±0.030 %), mass 233.21 ±0.46 kg (±0.20 %), LCG 1.6061 ±0.0011 m (±0.067 %) aft of bow, VCG 0.2640 ±0.0017 m (±0.63 %) above keel, GMT 47.76 ±0.61 mm (±1.3 %), roll radius of gyration 0.2329 ±0.0042 m (±1.8 %), and pitch radius of gyration 0.8434 ±0.0024 m (±0.28 %). The roll period in calm water was independent of the Froude number (Fr) and initial roll angle (a). At Fr = 0, 0.15, 0.22, the average roll period was 2.2298 ±0.0040 s (±0.18 %) for 76 runs, all Fr, and all initial roll angles. The initial roll angle variation was 3° to 25°. The natural roll period was 2.139 ±0.041 s (±1.9 %). The decay coefficient data were accurately approximated by a plane in three dimensions with Fr and initial roll amplitudes (a) as the independent variables. Examples are provided that show the average values for a single roll decay event from the logdecrement method are the same as the values by the curve fitting method within the uncertainty estimates.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125007180","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: 2

A High Speed Boat for the Hydrodynamic Testing of Fouling Control Coatings 一艘用于防污涂料水动力试验的高速船

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0009

J. T. Hunsucker, H. Gardner, G. Swain

{"title":"A High Speed Boat for the Hydrodynamic Testing of Fouling Control Coatings","authors":"J. T. Hunsucker, H. Gardner, G. Swain","doi":"10.5957/attc-2017-0009","DOIUrl":"https://doi.org/10.5957/attc-2017-0009","url":null,"abstract":"An 8.2 m high speed boat was modified to measure the drag and to provide real time video of ship hull fouling control coatings under boundary layer conditions that developed at speeds up to 15 m/s. It consists of a through hull Hydrodynamic Drag Meter (HDM) placed in a wet-well built into the aft section of the boat. The HDM consists of a load cell attached to a floating element balance and a high definition video camera to observe fouling. Test panels are attached to the load cell such that they remain flush with the hull. Fouled test panels are placed in the facility to observe the velocities required for fouling removal and changes in drag forces associated with different fouling community structure. Characterization studies of the HDM were undertaken to understand the overall accuracy of the novel testing system. These experiments included 1) Smooth acrylic drag measurement with the HDM and a Preston tube and 2) Drag measurements with the HDM on panels with 60- grit and 220-grit sandpaper. Smooth panel wall shear stress values obtained using the HDM were within experimental uncertainties of results from Preston tube. Roughness function values for 60-grit and 220-grit sandpaper agree within the experimental uncertainty of the Nikuradse-type roughness function for uniform roughness. Skin friction coefficients of a smooth panel determined on the HDM had an experimental uncertainty of around 5% for Froude numbers greater than 1. Roughness function values for a 220-grit and 60-grit sandpaper surface had maximum uncertainties of 11% and 13% respectively.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132505110","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: 0

Phase-averaged Tomographic PIV Measurements for a Surface Combatant in Pure Sway Maneuver 纯摇摆机动中水面作战人员的相位平均层析PIV测量

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0003

H. Yoon, F. Stern

{"title":"Phase-averaged Tomographic PIV Measurements for a Surface Combatant in Pure Sway Maneuver","authors":"H. Yoon, F. Stern","doi":"10.5957/attc-2017-0003","DOIUrl":"https://doi.org/10.5957/attc-2017-0003","url":null,"abstract":"Forces and moment and phase-averaged Tomographic PIV (TPIV) local flow measurements are performed in a 3 m × 3 m × 100 m towing tank for a 3.048-m long geometrically similar model of surface combatant 5415 in pure sway maneuver. Test conditions are for maximum drift angle 𝛽max = 10° and Froude number Fr = 0.28. The TPIV enables fully volumetric flow measurements and the use of 𝑄-criteria enables vortex volume visualization and core analysis. The objective of the experiment is to extend the knowledge for the static condition vortex separation onset and progression to unsteady dynamic conditions, including integrated CFD. Test conditions meet the IITC criteria for sway frequency and restricted water restrictions. Both the present and previous uncertainty assessment (UA) for forces and moment show acceptable values. The uncertainty estimates for TPIV is done by using a practical approach and the results are comparable with the earlier UA using a conventional approach. Integrated CFD simulations are used to identify flow vortices. The comparison with the previous TPIV results for static maneuver conditions show improvements for the present TPIV using a more advanced algorithm. The pure sway measurements at phases corresponding to straight-ahead and 𝛽max = 10° show similarities and differences with the static maneuver measurements, whereas at intermediate phases substantial vortex interactions and unsteady separation onset and progression is shown. The vortex core analysis shows similarities and differences in the core strength and trajectory with the static drift and dynamic pure yaw maneuvers. The present experiment is ongoing and the initial measurement results and analysis are discussed herein.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128781233","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: 0

An Evaluation of Planing Boat Trim Measurements 刨船纵倾测量的评价

Day 1 Wed, October 04, 2017 Pub Date : 2017-10-04 DOI: 10.5957/attc-2017-0025

Carolyn Q. Judge, B. Beaver, John Zseleczk

{"title":"An Evaluation of Planing Boat Trim Measurements","authors":"Carolyn Q. Judge, B. Beaver, John Zseleczk","doi":"10.5957/attc-2017-0025","DOIUrl":"https://doi.org/10.5957/attc-2017-0025","url":null,"abstract":"The resistance of a planing hull is known to be highly dependent on trim angle. For several reasons, trim is difficult to measure to the level of accuracy normally attained with other towing tank measurements such as resistance or speed. In a recent study intended to validate CFD methods for planing hulls, 4’ and 8’ long geosim models of the Generic Prismatic Planing Hull (GPPH) were built and tested at USNA. Significant differences were found between the trim of the two models so a separate test program was conducted which focused specifically on the trim measurement of these two models in calm water. Five different trim measurement methods were used simultaneously on one model and then used again on the other model. Trim angles were compared between measurement methods and between models. Trim measurements with the same model agreed well and are the basis for an evaluation of measurement methods. The trim measured on the two different size models did not agree well even though the same instruments were used in most cases. The paper discusses reasons for the confirmed differences in calm water running trim of the two models and suggests ways to take advantage of this knowledge to make the best use of towing tank tests for planing boat performance prediction.","PeriodicalId":348407,"journal":{"name":"Day 1 Wed, October 04, 2017","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130886858","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