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Three-Dimensional Stress Analysis of a Fiber-Reinforced Composite Thruster Blade 纤维增强复合材料推力器叶片三维应力分析
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-09
G. Lin
{"title":"Three-Dimensional Stress Analysis of a Fiber-Reinforced Composite Thruster Blade","authors":"G. Lin","doi":"10.5957/pss-1991-09","DOIUrl":"https://doi.org/10.5957/pss-1991-09","url":null,"abstract":"Stress calculations were carried out for a proposed fiber-reinforced composite thruster blade. The composite blade is constructed using multiple layers of braided fiber in a thick-shell skin layer; the core is filled with foam-type material and uses shear webs for internal support. The objective of this paper is to explore the rotating blade hydrodynamic design constraints of a typical composite blade by performing a 3-D finite element analysis. Two salient features are revealed from the numerical results: (1) maximum tip deflection of the composite blade can be quite large; (2) maximum through-the-thickness tensile stress in the skin layer thickness direction could become critical for higher loadings. It is demonstrated in the sample calculation that a sandwich-type composite blade can provide not only a means of weight-savings, but it also can have excellent structural stiffness and strength properties through proper geometric and material design.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129054635","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: 15
On the Strength of Highly Skewed Propellers 大倾斜螺旋桨的强度研究
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-10
E. Praefke
{"title":"On the Strength of Highly Skewed Propellers","authors":"E. Praefke","doi":"10.5957/pss-1991-10","DOIUrl":"https://doi.org/10.5957/pss-1991-10","url":null,"abstract":"A series of four propellers with different skewback angles and different blade area ratios was designed. The models of these propellers were manufactured and fitted with strain gages. Blade stresses were measured in a cavitation tunnel under a variety of working conditions including the simulation of a crash stop manoeuver. The results are presented as principal stresses normalized by their scaling factor. The second part of this paper concerns finite element calculations. The calculation method employed was validated by comparisons between measured and calculated stresses. Hereafter a number of different blade shapes was treated as well. The influence of blade area ratio, total skew back and other design parameters on blade stresses was evaluated and is discussed in the paper. It was found that the total skew angle mainly influences stress peaks at the trailing edge. The influence of the expanded area ratio is not very significant. To prevent blade failures in a high skew design it is recommended to strengthen the entire profile sections on the outer radii.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121516961","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
Machining Technology for Production of Ship Propellers 船舶螺旋桨生产的加工技术
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-04
M. Weinreich
{"title":"Machining Technology for Production of Ship Propellers","authors":"M. Weinreich","doi":"10.5957/pss-1991-04","DOIUrl":"https://doi.org/10.5957/pss-1991-04","url":null,"abstract":"Production of ship propellers by traditional machining practices is rather inefficient. This prompted a return to the engineering fundamentals from which traditional machining practices were developed and application of the fundamentals specifically to the unique problems of ship propeller production. Analysis and development of new approaches to machining technology, particularly applicable to ship propeller production, are described. Application of these new approaches to both three-axis and five-axis machining, of both separable propeller blades and monoblock propellers, are considered, resulting in the development of new machining practices applicable to these situations. These new machining practices are surprisingly different from traditional machining practices. Much of the new machining practice was successfully applied to actual ship propeller production. It is concluded that production efficiency can often be greatly improved with little or no degradation of the final product.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"7 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128804454","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
Propeller Hydrodynamic Loads and Blade Stresses and Deflections During Backing and Crashback Operations 倒车和倒车过程中螺旋桨水动力载荷和叶片应力和偏转
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-08
C. Jiang, T. Huang
{"title":"Propeller Hydrodynamic Loads and Blade Stresses and Deflections During Backing and Crashback Operations","authors":"C. Jiang, T. Huang","doi":"10.5957/pss-1991-08","DOIUrl":"https://doi.org/10.5957/pss-1991-08","url":null,"abstract":"An efficient and user-friendly analysis package (approach) has been developed to assess commercial skewed propeller loading and blade stresses and deflections during steady backing and crashback operations. Predictions of backing and crashback pressure distributions on blade surfaces are estimated from a modified propeller steady force computer program, MIT-PSF. A finite element computer program, NASTRAN, is used to predict blade stresses and elastic deflections. An interface computer program provides the data linkage between the hydrodynamic loading and structural response computer programs. This paper describes the approach to integrate MIT-PSF and NASTRAN computer codes to iteratively determine blade loading and deflection during steady backing operations and the modification of MIT-PSF code to account for flow separation during steady crashback operations. The computed results are compared with limited open water experimental data for one skewed and one conventional propeller tested in steady backing and crashback conditions.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"5 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116675277","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: 6
A Procedure for the Comparative Evaluation and Preliminary Design of Marine Propulsors 船用推进器的比较评价与初步设计程序
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-07
W. B. Coney
{"title":"A Procedure for the Comparative Evaluation and Preliminary Design of Marine Propulsors","authors":"W. B. Coney","doi":"10.5957/pss-1991-07","DOIUrl":"https://doi.org/10.5957/pss-1991-07","url":null,"abstract":"A systematic procedure for the design of a class of marine propulsors is described. This class of propulsors includes traditional propellers, ducted propellers, contra-rotating propellers, vane-wheel propulsors, and propellers operating with pre-or post-swirl stators. The topic of optimum propulsor load distributions is discussed. An algorithm for the determination of optimum radial circulation distributions for this class of propulsors is presented. This algorithm is incorporated in a vortex-lattice, lifting-line model for lightly to moderately loaded marine propulsors. This computer model also incorporates algorithms for the determination of minimum propeller chord lengths and thicknesses, as well as for the determination of optimum values of propeller rpm and diameter. Parametric studies and comparisons of various propulsor configurations can be readily carried out under the described model. A comparative study of marine propulsor alternatives for a given application is presented.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131085348","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
Hydrodynamic Analysis of Cycloidal Propulsors 摆线推进器的水动力分析
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-02
T. Brockett
{"title":"Hydrodynamic Analysis of Cycloidal Propulsors","authors":"T. Brockett","doi":"10.5957/pss-1991-02","DOIUrl":"https://doi.org/10.5957/pss-1991-02","url":null,"abstract":"A phenomenological description of the flow about, and performance of, cycloidal propulsors is extracted from the available literature. An approximate three-dimensional analysis, employing elements of a lifting-line model and an actuator-disk model, is assembled to predict the hydrodynamic loads on an arbitrary-geometry cycloidal propulsor. Both local blade-oriented and total circumferentially-averaged thrust and torque loads are computed·. Comparisons with experimental data and other analysis procedures show that the numerical implementation is generally adequate for preliminary design. Cavitation-inception properties of the blade sections are determined and an empirical prediction of tip-vortex cavitation inception is included. Noise levels are estimated for operation with extensive cavitation on the blade. Several blade-pitch motions are evaluated and it is found that various forms of modified cycloidal pitch control are advantageous for increased thrust from a given unit with little change in hydrodynamic efficiency or cavitation onset. Suggestions are given for future work.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116636978","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: 10
Transient Analysis of Propellers 螺旋桨瞬态分析
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-06
M. H. Kim, L. Glover, D. Mook
{"title":"Transient Analysis of Propellers","authors":"M. H. Kim, L. Glover, D. Mook","doi":"10.5957/pss-1991-06","DOIUrl":"https://doi.org/10.5957/pss-1991-06","url":null,"abstract":"The transient response of propellers to changes in rotation rate and forward speed is analyzed using a general unsteady vortex lattice method. This method is an extension of the well-known vortex lattice technique used for incompressible aerodynamics. The method described in this paper is not limited by aspect ratio, twist, camber or angle of attack as vortex breakdown does not occur near the surface of the propeller and separation occurs only along sharp edges of the blades. It is fully three-dimensional. Moreover, the position of and the vorticity distribution in the wake are obtained numerically at discrete time steps during the rotation. Steady flow can be treated by giving the propeller an impulsive start and allowing it to run under constant conditions until a steady-state emerges. The accuracy of the procedure was verified by comparing the predicted torque and thrust to known experimental results for a steady case. Unsteady results are given for varying rotation rates and forward speeds. It is demonstrated that the present version of the vortex-lattice method has the potential for handling a number of arbitrary maneuvers and transient conditions.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116951526","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
Precision Surfacing and Metrology of Naval Propellers 舰船螺旋桨精密堆焊与计量
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-03
D. Golini
{"title":"Precision Surfacing and Metrology of Naval Propellers","authors":"D. Golini","doi":"10.5957/pss-1991-03","DOIUrl":"https://doi.org/10.5957/pss-1991-03","url":null,"abstract":"This paper describes a novel approach to fabricating propeller blades to extremely high accuracy. The new approach includes iterative machining and rapid precision metrology. Iterative processes have been employed for decades in the optics industry. At Itek, robotics and computer-controlled surfacing techniques are used for iterative machining operations to produce ultra-precision optical surfaces. The technology developed at Itek for large optics has strong potential to transfer to the propeller industry. The surface of a propeller is difficult to measure accurately because of its odd shape and rapidly changing geometry, however, the Litton/Itek Surfitek Profilometer is capable of making this measurement to high accuracy. Surfitek was used to measure an Aegis Class Destroyer propeller blade to better than 0.001\" over the entire surface. Data was obtained at an average rate of one point per second, manually, while rates of up to ten measurements per second are achievable under machine control. The system is capable of operating in contacting or non-contacting modes and includes software to calculate departures of the measured surface from the desired nominal, develop an error map of the measured surface and provide machine command control for an iterative manufacturing surfacing operation. The measurement equipment and data reduction techniques used in a propeller manufacturing demonstration, as well as the initial results obtained using iterative machining techniques arc discussed.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122338167","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
Development of Marine Propellers with New Blade Sections for Container Ships 新型叶型集装箱船船用螺旋桨的研制
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-05
J. T. Lee, M. C. Kim
{"title":"Development of Marine Propellers with New Blade Sections for Container Ships","authors":"J. T. Lee, M. C. Kim","doi":"10.5957/pss-1991-05","DOIUrl":"https://doi.org/10.5957/pss-1991-05","url":null,"abstract":"A propeller design method using the newly developed blade section (KH18), which behaves better cavitation performance, is presented. Two-dimensional characteristics of the new blade section are compared with those of widely used NACA sections and the Eppler sections which were designed with prescribed pressure distributions along the foil surface. Experimental results for two-dimensional foil sections show that the lift-drag curve and the cavitation-free bucket diagram are wider compared to those of the existing foil sections. A lifting surface theory is used for the design of propellers with the developed section for a 2700TEU container ship. Since the most suitable chordwise loading shape is not known a priori, three types of loading shapes are selected from the two-dimensional analysis of the KH18 section. To investigate the influence of the chordwise loading shapes on the propeller performances, three propellers with different chordwise loading shapes were designed. Model test results show that the propeller using the KH18 section with less loading near the leading edge at the inner radii of 0. 7 radius and more loading near the leading edge at the outer radii has higher propulsive efficiency and better cavitation performance than the conventional propeller for this container ship application. Full-scale sea trial results with the selected propeller are also presented.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131474504","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
Pre-swirl Stator and Propeller/Stator Efficiency 预旋定子和螺旋桨/定子效率
Day 1 Tue, September 17, 1991 Pub Date : 1991-09-17 DOI: 10.5957/pss-1991-01
M. Gaafary, M. Mosaad
{"title":"Pre-swirl Stator and Propeller/Stator Efficiency","authors":"M. Gaafary, M. Mosaad","doi":"10.5957/pss-1991-01","DOIUrl":"https://doi.org/10.5957/pss-1991-01","url":null,"abstract":"A new method for improving the propeller efficiency due to locating a pre-swirl stator array has been developed by applying linearized lifting surface theory. This method has been applied on general stators and in particular stators of low aspect ratio. The obtained results of the stator 1nduced velocity are in exact agreement with the low aspect ratio wing theory. Incorporating the stator-induced velocity together with that of the propeller, a new velocity field has been found which led to an improvement of propeller efficiency. Using published theoretical and experimental data of propeller characteristics. A comparison has been made between propellers working alone and those working with stators. A gain in propeller efficiency has been achieved at larger advance coefficient and hence a decrease in the required propeller number of revolutions.","PeriodicalId":273145,"journal":{"name":"Day 1 Tue, September 17, 1991","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121558746","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
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