Day 1 Tue, May 26, 1981最新文献

Simplified Plotting of Nondimensional Propeller Parameters and its Application to a Propeller Series for High-Speed Small Craft 无量纲螺旋桨参数的简化绘制及其在某系列高速小艇螺旋桨中的应用

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-008

H. F. Hillman

引用次数: 0

Full Scale lcebreaking Stresses on Propellers of the Polar Star 北极星螺旋桨的全尺寸破冰应力

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-006

G. Antonides, A. Hagen, Don Langreck

{"title":"Full Scale lcebreaking Stresses on Propellers of the Polar Star","authors":"G. Antonides, A. Hagen, Don Langreck","doi":"10.5957/pss-1981-006","DOIUrl":"https://doi.org/10.5957/pss-1981-006","url":null,"abstract":"The POLAR Class icebreakers were the first large high powered icebreakers to use controllable pitch (GP) propellers. During their first three years of operation, significant structural problems were encountered with the internal mechanisms of the propellers. The initial failures were due largely to lack of understanding the loads imposed on the propeller by ice.\u0000 The Coast Guard decided to have the internal components of the propellers redesigned and rebuilt with the maximum strength that could be fit inside the same hub. At the same time the David W. Taylor Naval Ship R&D Center (DTNSRDC) instrumented the links and propeller blades to make stress measurements while actually breaking ice.\u0000 This paper briefly discusses the structural failures, the failure analysis, the design changes, full scale trial instrumentation, stress measurements, and computerized analysis of stresses along with fatigue life estimates.\u0000 The loads are not high enough to cause yielding of any of the structural components of the redesigned propeller, but are high enough to cause some fatigue damage. A computer program was written to analyze the stress data; the results are being used for predicting fatigue life, and for obtaining a statistical representation of the loads applied.","PeriodicalId":121399,"journal":{"name":"Day 1 Tue, May 26, 1981","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116927685","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

The Pinnate Propeller 羽状螺旋桨

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-003

P. Simonsson

引用次数: 3

Design of Baltic Ferries for the Eighties, Propellers and Aft End Vibrations 八十年代波罗的海渡轮的设计，螺旋桨和尾部振动

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-005

M. Kanerva, R. A. Salminen

{"title":"Design of Baltic Ferries for the Eighties, Propellers and Aft End Vibrations","authors":"M. Kanerva, R. A. Salminen","doi":"10.5957/pss-1981-005","DOIUrl":"https://doi.org/10.5957/pss-1981-005","url":null,"abstract":"The Wartsila Shipyards are building seven Baltic ferries between, 1979 and 1981, four of them are prototypes. The Turku Shipyards are building six of these ferries. Some of the main design criteria are high propulsive efficiency at various sailing conditions, low vibration and noise level, enough power for ice-navigation without problems, good maneuverability. To meet these criteria a lot of attention has to be paid for the design of hull form, propellers and aft ship construction.\u0000 Results of theoretical propeller calculations are presented. Model test results for three prototype ferries are presented, self-propulsion, cavitation and pressure pulse measurements. Comparative measurements were performed with a convential and a so called highly skewed c.p. propeller model.\u0000 Calculations of natural frequencies and modes and forced vibrations caused by propeller pressure pulses are presented. Estimates made for the vibration level are presented.\u0000 Forced vibration tests made with a vibration generator are presented.\u0000 During the sea trials the cavitation phenomenon has been photographed, pressure pulses and vibrations have been measured. Comparisons between theoretical propeller calculations, model tests and full scale measurements are presented.\u0000 Also vibration calculations, forced vibration tests and sea trial measurements are compared. Conclusions are drawn of the applicability of special c.p. propellers to reduce the vibration level in ice strengthened high-powered ferries.","PeriodicalId":121399,"journal":{"name":"Day 1 Tue, May 26, 1981","volume":"83 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113988194","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

lnvestigation into Modeling and Measurement of Propeller Cavitation Source Strength at Blade Rate on Merchant Vessels 商船桨叶速率下螺旋桨空化源强度建模与测量研究

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-010

L. M. Gray

{"title":"lnvestigation into Modeling and Measurement of Propeller Cavitation Source Strength at Blade Rate on Merchant Vessels","authors":"L. M. Gray","doi":"10.5957/pss-1981-010","DOIUrl":"https://doi.org/10.5957/pss-1981-010","url":null,"abstract":"The forces exerted on a ship's hull by propeller cavitation, modulated at blade rate, can be simply expressed as a function of the cavity volume velocity. Analytical models exist and are being refined that are used to predict this cavitation volume velocity for a given propeller in a given wake field. Very little data exist on how well these models work, primarily because of the difficulty in measuring cavity volumes on an operating propeller.\u0000 This paper reviews recent work, sponsored by the Naval Research Laboratory, that has investigated the correlation between analytical models of propeller cavitation and ·measured cavity volumes on both full- and model-scale propellers (stereo photography data). These comparisons demonstrate that accurate prediction of cavitation volume is extremely dependent on accurate knowledge of input variables, especially the propeller wake field. These comparisons also point out limitations in the accuracies of the existing models.\u0000 Results are presented of measurements of cavity volume velocities made by calibrating the ship vibration by using the principle of reciprocity. The accuracy of this reciprocal technique is demonstrated by a comparison of the results obtained with the acoustic pressures radiated by the cavity source. These measurements are analyzed for some of the time-varying characteristics of the cavitation. These results demonstrate that time-varying characteristics resulting from wake turbulence, rudder motion, ship motion, etc., introduce severe fluctuations in the source strength of propeller cavitation.","PeriodicalId":121399,"journal":{"name":"Day 1 Tue, May 26, 1981","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121246879","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

Sizing Segmental Section--Commercially Available Propellers for Small Craft 尺寸分段部分。商用小型船用螺旋桨

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-007

D. Blount, E. Hubble

引用次数: 4

Minimization of Unsteady Propeller Forces that Excite Vibration of the Propulsion System 激励推进系统振动的非定常螺旋桨力的最小化

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-012

N. A. Brown

{"title":"Minimization of Unsteady Propeller Forces that Excite Vibration of the Propulsion System","authors":"N. A. Brown","doi":"10.5957/pss-1981-012","DOIUrl":"https://doi.org/10.5957/pss-1981-012","url":null,"abstract":"A simple method is presented for predicting the periodic forces Which act on a propeller operating in a spatially nonuniform wake flow. The method, based on a 10w aspect ratio type of approximation, yields results with an accuracy comparable to that of elaborate computer calculations but with considerable physical insight.\u0000 More important, the analysis has been inverted to create a design method explicitly yielding the propeller blade shape which will in principle produce zero net force for a chosen periodic component in a given wake field. A rational method for the design, of the propeller blade outline in terms of the distribution and total amount of skew, tailored to the wake, is thereby provided.\u0000 Model-scale measurements have demonstrated periodic thrust· fluctuations for propellers with blade forms designed by this method which are less considered theoretically minimum for the total blade skew incorporated.\u0000 The analysis indicates, and the measurements tend to verify, that the significant blade skew is that of the leading edge rather than the midchord line. The amount of skew required for force minimization may be half that previously believed necessary, but there are any number of skew distributions of greater amount which will in principle null a selected force component, each tailored to the same wake distribution.\u0000 Construction and operation of propeller blade forms designed by this method appear quite feasible.","PeriodicalId":121399,"journal":{"name":"Day 1 Tue, May 26, 1981","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127451864","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

The Flowfield Near the Propeller of a Self-Propelled Slender Body with Appendages 带有附属物的自航细长体螺旋桨附近的流场

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-001

J. Schetz, H. P. Stottmelster

{"title":"The Flowfield Near the Propeller of a Self-Propelled Slender Body with Appendages","authors":"J. Schetz, H. P. Stottmelster","doi":"10.5957/pss-1981-001","DOIUrl":"https://doi.org/10.5957/pss-1981-001","url":null,"abstract":"An experimental investigation of the flow in the immediate vicinity of the propeller for a propeller-driven, slender body with and without appendages was conducted in the Virginia Tech wind tunnel, including measurement stations both immediately upstream and downstream of the propeller. Mean and turbulent flow quantities were examined for the disturbances induced by the appendages (a sail and/or a deck) which were added to the basic axisymmetric body to give it either a submarine-or airship-like arrangement and their interaction with the propeller. Five different model configurations were placed in a uniform free-stream flow corresponding to a Reynolds number of 4.5 x 105 based on body diameter. The streamlined appendages and their smooth, contoured junctures produced measurable disturbances in the flow behind the propeller of the body. The effect of adding the deck was to spread and flatten the velocity profile. Addition of the sail had no large influence on the mean flow quantities, whereas the combination of a sail and deck appeared to negate the stronger effect which the deck alone had on the wake. The other measured mean flow quantities - static pressure and flow angularity, appeared to have been dominated by the swirling motion produced by the propeller. The axial turbulence intensity was observed to increase in the wake of the sail outside the propeller slipstream. A peak in the turbulence profiles occurred at the radial stations in line with the tip of the propeller and along-the body axis centerline. A shift in position and decrease in magnitude of the peaks were observed when the sail was mounted on the body. The deck, on the other hand, produced no measurable increase in turbulence intensity, even though it increased the drag on the model more than did the sail. The performance of the propeller operating both behind the body and in an open \"water\" condition was analyzed with a computerized theory, and the predictions were compared with experimental results. Fair to good agreement was found.","PeriodicalId":121399,"journal":{"name":"Day 1 Tue, May 26, 1981","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132195716","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

A Study of Ice Class Rules for Propellers 螺旋桨冰级规则研究

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-004

P. Noble, V. Bulat

引用次数: 1

Periodic Blade Loads on Propellers in Tangential and Longitudinal Wakes 桨叶在切向和纵向尾迹中的周期性载荷

Day 1 Tue, May 26, 1981 Pub Date : 1981-05-26 DOI: 10.5957/pss-1981-011

R. Boswell, S. Jessup, Kidong Kim

{"title":"Periodic Blade Loads on Propellers in Tangential and Longitudinal Wakes","authors":"R. Boswell, S. Jessup, Kidong Kim","doi":"10.5957/pss-1981-011","DOIUrl":"https://doi.org/10.5957/pss-1981-011","url":null,"abstract":"Periodic single-blade loads were measured on model propellers in inclined flow and in a single-cycle circumferentially non-uniform longitudinal velocity field. The experimental results were correlated with predictions by the following methods:\u0000 1. A quasi-steady procedure developed by McCarthy at David W. Taylor Naval Ship Research and' Development Center (DTNSRDC)\u0000 2. An unsteady lifting surface theory developed by Tsakonas and his colleagues at Davidson Laboratory,\u0000 3 An unsteady lifting Surface theory developed by Kerwin and Lee. at MIT,\u0000 4. A refinement by Kerwin to the method of Kerwin and Lee to consider the inclination of the propeller slipstream.\u0000 In inclined flow, all four of the calculation methods evaluated consistently underprediCted1 the experimental values of the periodic single-blade loads. The method of Kerwin, which considers the inclination of the slipstream relative to the propeller axis, produced the best correlation· with experimental values. These correlations show that the inclination of the propeller slipstream relative to the propeller axis significantly influence the periodic single-blade loads. The importance of this inclination· increases with increasing ,time-average loading.","PeriodicalId":121399,"journal":{"name":"Day 1 Tue, May 26, 1981","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1981-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127343333","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: 4