Day 1 Tue, May 15, 1984最新文献

Precise Sterntube and Strut Bearing Alignment without Boring 精确的艉管和支柱轴承对准，无需镗孔

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-13

J. M. Wilson

引用次数: 0

Cavitation Observations and Measurement of Propeller Excited Pressure Pulses in Fullscale and in Model Tests 螺旋桨受激压力脉冲的空化观测和模型试验测量

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-04

Jurguen Friesch

引用次数: 0

Static and Dynamic Analysis of Marine Propeller Blades Using a Customized Finite Element Method 船用螺旋桨叶片静、动特性的定制有限元分析

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-10

G. K. Politis

{"title":"Static and Dynamic Analysis of Marine Propeller Blades Using a Customized Finite Element Method","authors":"G. K. Politis","doi":"10.5957/pss-1984-10","DOIUrl":"https://doi.org/10.5957/pss-1984-10","url":null,"abstract":"Statistical analyses of data from eight different sandstones and shaly sandstone formations show that linear combinations between porosity and clay content explain changes in elastic moduli. The outliers highlight a mineralogy effect on elastic rock properties. The model underestimates all moduli with stiff cements (calcite and pyrite) since it is developed for sandstones with weak cements (clay minerals). Thus, the model can be used for quality checking data and predicting.\u0000 A customized Propeller blade and hub static and dynamic analysis using a finite element method has been developed. Dynamic analysis results include: natural modes and frequencies of vibration and time history response.\u0000 The problem of voluminous input data for the finite element method is bypassed, by using an automatic propeller- hub data generation method. Special features of the data generation method are its flexibility in the number and distribution of elements in the chordwise and spanwise directions, allowing thus its straightforward application to usual and unusual (e.g. highly skewed) propeller blade geometries and its capability to accept pressure distributions directly from a lifting surface computer program.\u0000 Some examples of application of the program to static and dynamic analysis of propeller blades are presented and compared with existing experimental data. Sensitivity analysis of the results with respect to the finite element discretization used is also presented.","PeriodicalId":347911,"journal":{"name":"Day 1 Tue, May 15, 1984","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133789492","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

Detailed Turbulent Flowfield Measurements Immediately Behind a Propeller 详细的湍流流场测量立即后面的螺旋桨

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-03

M. Kotb, J. Schetz

{"title":"Detailed Turbulent Flowfield Measurements Immediately Behind a Propeller","authors":"M. Kotb, J. Schetz","doi":"10.5957/pss-1984-03","DOIUrl":"https://doi.org/10.5957/pss-1984-03","url":null,"abstract":"An experimental investigation of the flow in the immediate vicinity of a free-running propeller was conducted in the VPI 2 m x 2m (6ftx6ft) wind tunnel. The performance of a three-bladed model propeller was measured for three-pitch/ diameter ratios. The P/D=1.572 model was selected for a detailed flow field study. The mean flow and all turbulence quantities were measured for three different axial stations behind the rotor .025,.23, and .50 diameters. The rest was done at a free stream velocity corresponding to a Reynolds number based on the propeller diameter of 2.58 x10^5. The results obtained showed that it is important to be as close as possible to the rotor place in order to get representative values for the flow parameters right at the disk plane. The blade tip effects were clear, and they manifest themselves in the form of higher peaks in turbulence intensity and shear stress profile. Measurements also indicated that the radial turbulence intensity represents the highest value, and the radial-peripheral correlation is the highest among the three velocity fluctuation correlation functions. The performance of the propeller model test was analyzed with a computerized theory, and the predictions were compared with experimental results. A satisfactory agreement was found as far as global values are concerned; the however less satisfactory agreement was obtained for detailed flow parameters.","PeriodicalId":347911,"journal":{"name":"Day 1 Tue, May 15, 1984","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125375553","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

Stress Analysis of Highly Skewed Propeller Blades Using the Finite Element Method 大倾角螺旋桨叶片应力有限元分析

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-12

C. S. Sunnersjo

{"title":"Stress Analysis of Highly Skewed Propeller Blades Using the Finite Element Method","authors":"C. S. Sunnersjo","doi":"10.5957/pss-1984-12","DOIUrl":"https://doi.org/10.5957/pss-1984-12","url":null,"abstract":"The design of highly skewed propellers requires that special attention is given to the stress analysis of the blade. In this paper a number of Finite Element computer programs are applied to different element layouts on a highly skewed reference blade with uniform load. The calculated stresses are compared with measurements, the result of which shows that a certain care must be exercised for the choice of elements as well as node-pattern if the resulting accuracy is to be acceptable.\u0000 In order to simplify indata preparation a suite of existing programs giving propeller geometry, profile loading conditions and pressure distribution have been linked together and supplemented with a program that converts the output from these programs into a complete in data deck for a Finite Element Program. The program package produces plots and print-outs at a number of control stations during the process. The thus developed method for calculation of load and resulting stress distribution is applied to the SSPA skew propeller series. Stress distribution for forward and backing cases are studied as a function of skew angle, all other factors being kept constant. The results indicate an increase in stress with skew, which is of particular importance during backing.\u0000 Hydroelastic effects become potentially dangerous during backing of extreme skew-back propellers. When gradually increasing speed during backing a critical speed is approached at which the hydrodynamic forces and moments increase faster with angle of attack than the restoring elastic forces and moments do. This is a point of instability. Also well below the critical speed the hydrodynamic effects cause an increase in stress levels that cannot be neglected. One approximative and one more rigorous method to determine these effects are presented.","PeriodicalId":347911,"journal":{"name":"Day 1 Tue, May 15, 1984","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123732470","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

Correlation of Theory and Experiment: Hull Surface Pressures with a Cavitating Skewed Propeller (AO-177 Vessel) 理论与实验的相关性:空化倾斜螺旋桨的船体表面压力(AO-177)

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-02

P. Kaplan, J. Bentson

引用次数: 0

Studies of Different Measures for the Reduction of Propeller-Induced Pressure Pulses on the Ship Hull 减小船体螺旋桨压力脉冲的不同措施研究

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-11

E. Bjarne

引用次数: 0

Technology Trends for Naval Propulsion 海军推进技术趋势

Day 1 Tue, May 15, 1984 Pub Date : 1984-05-15 DOI: 10.5957/pss-1984-20

J. Nelka

引用次数: 0