{"title":"Pressure and Velocity Correlation in the wake of a Propeller","authors":"F. Di Felice, M. Felli, G. Giordano, M. Soave","doi":"10.5957/pss-2003-10","DOIUrl":"https://doi.org/10.5957/pss-2003-10","url":null,"abstract":"An experimental study of the flow and pressure field behind a marine propeller in a non-cavitating regime is reported. The flow field measurements, in phase with the propeller revolution angle, were performed by using Particle Image Velocimetry (PIV), and propeller wake evolution from the blade trailing edge to the slipstream contraction (near wake) was investigated. Pressure measurements, performed in four radial and eight longitudinal positions downstream of the propeller, were carried out at different advance coefficients, in order to point out the wake structures at different propeller operating conditions. The transducer data are analyzed by using the slotting technique to reconstruct the pressure in phase with the revolution of the reference blade. Finally, the correlation of the flow field and pressure signals is performed.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132532717","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}
{"title":"Numerical Analysis of Surface-Piercing Propellers","authors":"Y. L. Young, S. Kinnas","doi":"10.5957/pss-2003-04","DOIUrl":"https://doi.org/10.5957/pss-2003-04","url":null,"abstract":"A 3-D low-order boundary element method, PROPCAV, has been extended to predict unsteady hydrodynamic forces and ventilation patterns on a surface-piercing propeller. The negative image method is used to account for the effect of the free surface. The ventilated cavity patterns at every time step is determined iteratively by satisfying both the kinematic and the dynamic boundary conditions. The detachment locations of the ventilated cavities are determined iteratively by applying a condition similar to the Villat-Brillouin smooth detachment criterion. Finally, the coupling of boundary element method with a finite element method to include hydroelastic effects is presented.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130547218","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}
{"title":"PTFE Compound Bearing for Water Lubricated Shaft Systems","authors":"S. Yamajo, F. Kikkawa","doi":"10.5957/pss-2003-09","DOIUrl":"https://doi.org/10.5957/pss-2003-09","url":null,"abstract":"The paper outlines the development and applications of compound bearings made of PTFE (Poly Tetra Fluoro Ethylene) and synthetic rubber, which enable the shaft to start up without initial lubricating water. The unique characteristic is the three-layer structure using elastic, synthetic rubber which is sandwiched between the PTFE compound and the outer metal shell. This special structure is designed to solve bearing issues that are incompatible with each other. That the bearing has sufficient hardness to be excellent against wear and yet is flexible to compensate for shaft misalignment and vibration. Friction characteristics and performance data are introduced comparing PTFE and conventional rubber bearings. Long-time running tests are carried out in very demanding conditions and the test data are shown. Over 15 years of actual operational service data on naval vessels and high speed, long-distance cruising ferries are introduced.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129696827","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}
{"title":"Shaft Alignment Optimization With Genetic Algorithms","authors":"Davor Sverko","doi":"10.5957/pss-2003-01","DOIUrl":"https://doi.org/10.5957/pss-2003-01","url":null,"abstract":"A solution to the shaft alignment problem is a set of prescribed bearing offsets that ensure an acceptable load distribution among the shaft-supporting bearings. Acceptable load distribution implies not only all positive bearing reactions under all operating conditions of the vessel but also an acceptable relative-misalignment between the shaft and the bearing. In a marine environment, the difficulty is not in finding a single suitable solution to the above criteria, but rather in defining the optimal set of solutions capable of accommodating the extreme bearing disturbances - resulting mainly from hull deflections and thermal deviation. As the problem is stochastic, with an infinite number of satisfactory bearing offsets, it is appropriate to apply the Genetic Algorithm (GA) optimization procedure to search for the optimal set of solutions, rather than rely on the plain trial and error approach or some of the step-by-step conventional search algorithms. With an ability to conduct a parallel search throughout the solution space, the GA is particularly well suited for the problem at hand, as it has the capacity to simultaneously provide multiple sets of bearing offsets that satisfy loading conditions at bearings.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130831924","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}
W. Facinelli, A. J. Becnel, J. Purnell, Robert F. Blumenthal
{"title":"Design of an Advanced Waterjet","authors":"W. Facinelli, A. J. Becnel, J. Purnell, Robert F. Blumenthal","doi":"10.5957/pss-2003-07","DOIUrl":"https://doi.org/10.5957/pss-2003-07","url":null,"abstract":"State-of-the-art computer programs have been used to design a water jet for marine propulsion applications. The design was accomplished in an iterative process between a potential-flow design code and a folly viscous, three-dimensional computational fluid dynamics analysis program. These tools were first directed at the evaluation of three options: a single rotating blade row plus a stator; a rotating blade set consisting of main blades and splitter blades, plus a stator; and two co-rotating blade rows (an inducer and a kicker) plus a stator. In the second step of the design process, the single rotor/stator concept was optimized to maximize efficiency while matching a given design point. The resulting design is predicted to have much improved cavitation performance compared with a design accomplished with older techniques. Other advantages are reduced weight, shorter length, and lower manufacturing cost.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122705169","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}
{"title":"Experiences using a Coupled Viscous/Potential-Flow Unsteady Propeller Analysis Procedure","authors":"S. Black, T. Michael","doi":"10.5957/pss-2003-03","DOIUrl":"https://doi.org/10.5957/pss-2003-03","url":null,"abstract":"Software developed at the Massachusetts Institute of Technology for the unsteady propeller analysis and effective wake calculation has been transitioned to the Naval Surface Warfare Center, Carderock Division. The lifting surface propeller software is designed to be coupled with a three-dimensional Reynolds-averaged Navier-Stokes flow code. . The basic philosophy of the coupling remains the same, but the procedure for the coupling was largely revised and validated by the authors. Sample cases for the coupled lifting-surface/RANS analysis package are included in this paper and compared with experimental data. These sample cases show that this analysis procedure has great potential for the computation of propulsor maneuvering forces.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123832231","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}
{"title":"Modeling of Contra-Rotating and Ducted Propellers via Coupling of a Vortex-Lattice with a Finite Volume Method","authors":"H. Gu, S. Kinnas","doi":"10.5957/pss-2003-06","DOIUrl":"https://doi.org/10.5957/pss-2003-06","url":null,"abstract":"This paper describes a general numerical method of analyzing propeller hydrodynamic performance, with emphasis on contra-rotating (CRP) and ducted propellers. The main difficulty in this analysis is the complexity of the interaction between the two blade rows, in the case of a CRP, and between the propeller and the surrounding duct, in the case of a ducted propeller. The current method couples a Vortex-Lattice Method (VIM) applied to each of the blade rows of the CRP or the propeller inside the duct, with a Finite Volume Method (FVM) based Euler solver applied to the global flow-field, in order to account for the interactions mentioned above. The VIM solver (MPUF-3A) solves for the potential flow in the vicinity of the propeller and predicts the pressures, forces and moments, and cavity patterns on the blades. The FVM solver (GBFLOW-3X/3D) converts the pressure forces on the blades to body forces inside the flow domain and then solves the Euler equations with respect to the total velocity field and pressure. By subtracting the propeller-induced velocities, from the total flow, the \"effective wake\" is determined. For CRPs, the \"effective wake\" for each blade row includes the interaction with the other blade row. For ducted propellers, the \"effective wake\" includes the interaction with the duct. The \"effective wake\" is then provided to the VIM solver for a new round of body force computation. This iterative process between the VIM and the FVM is repeated until convergence. Several validations of results from the current numerical method with those of other computational methods and with those measured in experiments are presented.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123618443","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}
{"title":"The Preliminary Design of Advanced Propulsors","authors":"J. Kerwin","doi":"10.5957/pss-2003-02","DOIUrl":"https://doi.org/10.5957/pss-2003-02","url":null,"abstract":"Potential propulsors for current applications may vary in complexity from traditional open propellers to podded propulsors, multiple blade-row ducted units, and waterjets. In the past, the lifting-line theory has been an effective tool in establishing the principal characteristics of an optimum propeller design. Similarly, turbomachinery through-flow theory has been effective in preliminary estimates for internal flow devices such as waterjets. What is currently lacking is a single, unified approach that can be used for a wide range of propulsor types. This paper presents a possible solution to this problem, based on recent experience in detailed design methods based on coupling lifting surface theory with axisymmetric RANS/Euler solvers. In the present method, lifting-line representations of the blade rows are coupled with an axisymmetric Euler/Boundary Layer solver to provide preliminary estimates of propulsor performance.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124829323","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}
{"title":"Numerical Modeling of Podded Propulsors and Rudder Cavitation","authors":"S. Kinnas, S. Natarajan, Hanseong Lee","doi":"10.5957/pss-2003-05","DOIUrl":"https://doi.org/10.5957/pss-2003-05","url":null,"abstract":"Various computational methods that have been developed in the past are combined in this paper to predict: (a) the performance of podded propulsors, and (b) the sheet cavitation on a rudder which is subject to the flow of an upstream propeller. An 3-D Euler-based finite volume method (GBFLOW-3D) is used to predict the flow around a pod with a strut, and is coupled with MPUF-3A, a lifting surface vortex-lattice method, which is applied to the propeller(s) of the pod. The propellers are modeled via body forces in GB FLOW. The 3-D effective wake for each of the propellers of the pod is evaluated by subtracting from the total inflow (determined in GBFLOW-3D) the velocities induced by the same propeller ( determined in MPUF-3A). Several iterations between GBFLOW-3D and MPUF-3A are performed until convergence is reached. The three-way interaction among the pod/strut and the two propellers is fully accounted for at the end of the iterative process. The inflow to the rudder is determined by applying GBFLOW-3DIMPUF-3A on the propeller upstream. Once the propeller-induced flow to the rudder is evaluated, PROPCAV (a potential-based boundary element method), is used to predict the cavitation patterns on the rudder. The effects of the hull are considered by using the image model in PROPCAV. Several validation studies with other methods, some analytical solutions, and experiments are presented.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134161764","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}
{"title":"Advanced Technology of Propeller Shaft Stern Tube Seal","authors":"S. Yamajo, I. Matsuoka","doi":"10.5957/pss-2003-08","DOIUrl":"https://doi.org/10.5957/pss-2003-08","url":null,"abstract":"The paper outlines the details concerning historical perspective and recent developments to meet a requirement that lube oil and seawater leakage must be prevented under any circumstances. Using a compressed air chamber, the lube oil in the stern tube is completely separated from seawater by providing a controlled \"buffer zone\" between lip-type sealing rings. A constant quantity of compressed air supplied from within the ship passes through the air chamber and is spouted into the sea. An air control unit automatically detects any change of draft level and adjusts the pressures to maintain the optimum pressure on each sealing ring. The key mechanism to detect the draft change correctly and to adjust the pressure balance is explained. Specific design and project applications for the stern tube air seal on ocean-going and other marine vessels using line shaft propulsion and pod propulsion are explained.","PeriodicalId":270146,"journal":{"name":"Day 1 Wed, September 17, 2003","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132452658","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}
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
