{"title":"Proposals for Design Methodologies for Ice Class Propellers","authors":"N. Bose, B. Veitch, Michael Doucet","doi":"10.5957/pss-1997-05","DOIUrl":"https://doi.org/10.5957/pss-1997-05","url":null,"abstract":"This paper describes proposals for design methodologies for ice class propellers. The design rationale for these proposals uses limit state analysis. To date, the methods are tentative as they form proposals for standards. The proposals include both steady and unsteady loading components arising from ice and hydrodynamic loads and the structural response in the form of direct stresses, fatigue loadings and existing residual stresses. Exceptional loads arising from impact loads of ice on stopped blades are also considered as a separate limit state.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133165843","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":"Water Jet Propulsion-Operational Experience from Large Installations","authors":"R. Svensson","doi":"10.5957/pss-1997-01","DOIUrl":"https://doi.org/10.5957/pss-1997-01","url":null,"abstract":"To make a power prediction for a propeller driven vessel the hull resistance is usually first determined by separate tests. After that the thrust deduction, wake fraction and relative rotative efficiency are determined in self propulsion tests. After scale effects have been taken into consideration also the model basin's statistical correlation factors are usually put on top of that to predict the required power and shaft speed for the full scale vessel. Theoretically the same procedure could be used for water jet propelled craft. However the measurements involved in the self propulsion tests with water jets, like flow rate measurements must be extremely accurate to give a reliable end result. Further scale effects are more difficult to predict. By extensive testing in the Kamewa' s cavitation tunnels as well as in full scale Kamewa has developed software that very accurately predicts full scale flow rates and shaft speed for given shaft power and ship speed.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122087608","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":"Investigating Some Fundamental Notions of Propulsion Shaft Alignment","authors":"J. Woodward","doi":"10.5957/pss-1997-08","DOIUrl":"https://doi.org/10.5957/pss-1997-08","url":null,"abstract":"Alignment of the shaft connecting driver and load may be done with the shaft regarded as a rigid body, as an elastic body with journal centers in line, or as an elastic body whose elasticity may be exploited by adjusting the heights of bearings. Through several example cases, the paper questions whether the rigid body school might benefit from moving bearings to exploit elasticity, or conversely, whether moving bearings to benefit bearing load distribution might have undesirable consequences such as excessive bending stress. Alternatives to rigid body alignment are explored through the use of a pump-motor combination for which it is found that reasonable adjustments of bearing heights produces large changes in bearing loads and in shaft bending stress; however neither appears to reach dangerous levels. Applied to a long, multi-bearing shaft for which a \"fair curve\" alignment might be applied, high levels of combined bending and torsional stress are found, but only for extreme cases. The paper lastly applies elastic bending formulas in testing several common-place rules for coping with the elastic deflections of uncoupled shaft sections.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"155 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132704460","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":"Prediction of Performance of Waterjet Propulsors by Surface Panel Method","authors":"I. Moon, Chang-sup Lee, In-Haeng Song, Ki-Sup Kim","doi":"10.5957/pss-1997-02","DOIUrl":"https://doi.org/10.5957/pss-1997-02","url":null,"abstract":"This paper describes a potential-based panel method formulated for the prediction of the steady performance of a waterjet propulsor. The method employs normal dipoles and sources distributed on the solid surfaces such as the impeller/stator blades, hub and duct, and normal dipoles in the shed wakes trailing the impeller and stator to represent the potential flow around the waterjet propulsor. To define a closed boundary surface, the inlet and outlet open boundary surfaces are introduced where the sources and dipoles are distributed.\u0000 The kinematic boundary condition on the solid boundary surface is satisfied by requiring that the normal component of the total velocity should vanish. On the inlet surface, the total inflow flux into the duct is specified, and on the outlet surface the conservation of mass principle is applied to evaluate the source strength. The solid surfaces are discretized into a set of quadrilateral panel elements and the strengths of sources and dipoles are assumed constant at each panel. Applying this approximation to the boundary conditions leads to a set of simultaneous equations.\u0000 Systematic numerical tests show that the present numerical method is fast and stable. In order to validate the present method, sample computations are carried out first for the case of a screw within an axial circular cylinder, and a conventional axial flow fan, having a similar geometry as the waterjet propulsor, and then for the case of a waterjet propulsor on which experiments are carried out at KRISO(Korea Research Institute of Ships and Ocean Engineering). Comparisons between predictions and experiments are promising.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132080014","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":"Optimization and Stochastic Modeling Applied to Propulsion Shafting Alignment","authors":"Steven Eugene Owen","doi":"10.5957/pss-1997-10","DOIUrl":"https://doi.org/10.5957/pss-1997-10","url":null,"abstract":"Two aspects of propulsion shaft alignment analysis are discussed: a) finding an optimized solution by minimizing the deviation between bearing loads, and b) determining the acceptability of the optimized solution (or any alignment solution) by calculating the probability of acceptable bearing loads that result from a simulated series of random bearing offset events.\u0000 The optimizing method is straight forward: the bearing loads are calculated using a· series of bearing offsets which are independently allowed to vary within a range of predetermined displacements. The acceptability of the alignment solution is judged against desired bearing load criteria. Several types of internal and external causes of bearing elevation effects are recognized, and the combination of the effects are presented as shaft alignment conditions.\u0000 By distributing the nominal offset solutions about their most likely values, a simulation can be performed which reveals the probability of an acceptable solution when using the same acceptability criteria used in the optimizing calculations. A triangle distribution is shown in a subroutine and can be employed in an algorithm designed to randomly distribute the bearing offsets. Methods are described and examples are presented which show the application of shaft alignment optimization and probability analysis to produce alignment solutions which meet example criteria.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128128615","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":"New Alloys and Service Performance on High Speed Crafts","authors":"J. A. Philin, S. S. Ushkov, V. A. Chaschinov","doi":"10.5957/pss-1997-06","DOIUrl":"https://doi.org/10.5957/pss-1997-06","url":null,"abstract":"This paper presents the test results of new propeller alloys developed by the authors to extend the service life of the propellers used on oceangoing hydrofoil craft. Comparative tests of high speed propellers cast with a new grade of corrosion resistant nitrided steel alloy as well as titanium alloys are summarized. These propellers have high specific strength and corrosion resistance in sea water. In addition, the design of these propellers was changed to have large skew to reduce the cavitation effects on the inclined propeller operation.\u0000 Steel shafting with oxide coatings and graphite bearing compounds is introduced to avoid corrosion in sea water when titanium propellers are fitted. This approach resulted in the successful corrosion isolation of the titanium propellers from the shafting and hull. When these new propellers were installed they significantly increased the propeller service life on the oceangoing hydrofoil craft.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114730786","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 Development of a New Generation of Propeller Designs for Workboats","authors":"G. Platzer","doi":"10.5957/pss-1997-07","DOIUrl":"https://doi.org/10.5957/pss-1997-07","url":null,"abstract":"This paper describes the development of a series of propeller designs incorporating advanced technology for workboats, which have been found to reduce propeller-induced vibration levels by approximately 50% and increase propeller efficiency by up to 7%, as compared to conventional workboat propeller designs. To date, the New Generation propeller design series has been installed on more than 30 different applications in both open and ducted propeller configurations ranging from 3 to 12 ft (0.9 to 3. 6 m) in diameter.\u0000 An analysis of the existing propeller design technology and the poor operating environment typical of these applications is given. A description of the design process used to develop an advanced blade section profile and radial blade geometry distributions optimized for the given operating conditions is given. The results of an analytical study to determine the preferred geometry characteristics to optimize backing performance is presented. Full-scale operating experience is given, including comparisons of measured vibration, bollard thrust, propulsive efficiency and backing characteristics with predicted performance.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125855367","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":"Utilization of Carbon Fiber Torque Tubes in Ultra-Light, High Powered Propulsion Systems","authors":"G. Kirschey, Lawrence A. Burich","doi":"10.5957/pss-1997-04","DOIUrl":"https://doi.org/10.5957/pss-1997-04","url":null,"abstract":"There has long been a need for increasing the limits of propeller shafting. Carbon fiber torque tubes satisfy many of these needs by allowing for greater spans, higher speeds, lower weights, and better balance as compared to steel or aluminum torque tubes. These torque tubes are usually connected to a device on either end with the purpose of compensating for misalignment. This misalignment can be created by several conditions such as machining tolerances, installation, thermal growth, and/or hull flexure. These devices are typically rigidly or flexibly connected to the torque tube. Now, with the added advantages of carbon fiber materials and the latest fastening advances, a shafting system with more benefits than steel or aluminum can be used.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131186612","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":"Statistical Analysis and Design of Recreational Outboard Propellers","authors":"M. Mizina, R. Latorre","doi":"10.5957/pss-1997-03","DOIUrl":"https://doi.org/10.5957/pss-1997-03","url":null,"abstract":"A large number of recreational craft are now built throughout the world. This has resulted in the possibility of using different outboard motors and types of outboard motor propellers. These propellers have been developed by trial and error over the past decades. Consequently they represent a state of the art for a number of propeller designs including the \"cupped propeller\" with a bent trailing edge.\u0000 The present paper presents an overview of these outboard motor propellers. It then examines the possibilities for the performance improvement when the propellers are designed and manufactured with spoilers. Finally the results of systematic calculations are presented to illustrate the possibility of the propeller with spoiler for cavitating outboard motor propellers.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131593029","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":"Detecting and Correcting Propulsion Shafting Misalignment","authors":"Andrew A. Donaghy","doi":"10.5957/pss-1997-09","DOIUrl":"https://doi.org/10.5957/pss-1997-09","url":null,"abstract":"The intent of this paper is to place in the hands of owners and ship repairers, phrased in simple terms, a guide to recognize problems caused by propulsion shafting misalignment and provide well tested methods to resolve them. Since the paper is based precisely on the technical assistance that the author has been giving owners and repairers for the past three and a· half decades on shafting realignment, the information should be particularly useful to the people who are actually involved in propeller and line shafting repair.","PeriodicalId":244577,"journal":{"name":"Day 1 Tue, September 23, 1997","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120922921","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}