scholarly journals One-Dimensional Analysis Method for Cavitation Instabilities of a Rotating Machinery

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Satoshi Kawasaki ◽  
Takashi Shimura ◽  
Masaharu Uchiumi ◽  
Yuka Iga

Rotating cavitation is an important problem, which makes it difficult to design reliable rotating machines. In this study, a simple analysis method that tried to evaluate the cavitation instabilities of a rotating machinery by using one-dimensional (1D) system analysis software was attempted. In this method, cavitation compliance and mass flow gain factor are distributed in each flow path of the inducer. Analysis results show that cavitation instabilities, including rotating phenomena, exist. With the evolved analysis model, effects of various parameters on the eigenvalues of the system were investigated. Analysis results agreed with inducer test results qualitatively. Furthermore, by the analysis considered whirl motion of the rotor, effects of it on cavitation instabilities were investigated.

1983 ◽  
Vol 105 (2) ◽  
pp. 383-392 ◽  
Author(s):  
A. W. Leissa ◽  
M. S. Ewing

A great deal of published literature exists which analyzes the free vibrations of turbomachinery blades by means of one-dimensional beam theories. Recently, a more accurate, two-dimensional analysis method has been developed based upon shallow shell theory. The present paper summarizes the two types of theories and makes quantitative comparisons of frequencies obtained by them. Numerical results are presented for cambered and/or twisted blades of uniform thickness. Significant differences between the theories are found to occur, especially for low aspect ratio blades. The causes of these differences are discussed.


2018 ◽  
Vol 14 (1) ◽  
pp. 61-73
Author(s):  
Dwi Safitri ◽  
Abdul Muis Muslimin ◽  
Rosalina R Mirino

A study has been conducted on evaluating the coverage signals transmitting power of BTS Telkomsel in the city of Manokwari using geographic information system analysis. This study aims to analyze the coverage of the signal transmitting power of each  BTS Telkomsel in the study area based on the residential and administrative variables, by determining the slope shadow area using 3-dimensional analysis and mapping the coverage of Telkomsel's cellular network in Manokwari Regency with the analysis method of Geographic Information System (GIS). From the study, Telkomsel GSM 2G signal coverage map was obtained based on residential variables, the area covered by the signal is in West Manokwari District around 99.78% covering an area of 9.3 km2, in East Manokwari District around 96.24% covering 2.05 km2, At South Manokwari District around 12.3% covering 0.81 km2 and in North Manokwari District there is no residential area covered by the signal. Based on administrative boundaries, the area of ​​the district covered by GSM 2G Telkomsel is obtained, in West Manokwari District around 64% covering an area of  41.1 km2, in East Manokwari District around 80% covering 15 km2, in South Manokwari District around 50.31% covering 3.7 km2 and in North Manokwari District which is about 4% covering 1.2 km2. With the 3-dimensional analysis method it can also be seen that the slope shadow area that is not reachable by Telkomsel's 2G GSM signal. From the results of data processing, a slope shadow area with an area of ​​0.2 km2.


2008 ◽  
Vol 33-37 ◽  
pp. 1259-1264
Author(s):  
W.C. Lee ◽  
Chae Sil Kim ◽  
H.O. Choi ◽  
Y.G. Jung ◽  
Jung I. Song

This article proposes a novel simulation technique to predict the reasonable dynamic characteristics of a suspension seat for heavy machinery using a commercial multibody dynamic analysis code, ADAMS. The dynamic model is simulated with the specific condition such as sinusoidal and sweep input. The experiment test for actual suspension seat is conducted for reviewing the dynamic simulation model with same input condition. As the simulation results shows good agreements with experimental test results, the dynamic analysis model is reasonable and will be very helpful for predicting the dynamic characteristic for the suspension seat for heavy machinery and for designing the other type seats with the other suspension mechanism types.


Author(s):  
A. W. Leissa ◽  
M. S. Ewing

A great deal of published literature exists which analyzes the free vibrations of turbomachinery blades by means of one-dimensional beam theories. Recently, a more accurate, two-dimensional analysis method has been developed based upon shallow shell theory. The present paper summarizes the two types of theories and makes quantitative comparisons of frequencies obtained by them. Numerical results are presented for cambered and/or twisted blades of uniform thickness. Significant differences between the theories are found to occur, especially for low aspect ratio blades. The causes of these differences are discussed.


Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 188-196 ◽  
Author(s):  
Esther T. Beierl ◽  
Markus Bühner ◽  
Moritz Heene

Abstract. Factorial validity is often assessed using confirmatory factor analysis. Model fit is commonly evaluated using the cutoff values for the fit indices proposed by Hu and Bentler (1999) . There is a body of research showing that those cutoff values cannot be generalized. Model fit does not only depend on the severity of misspecification, but also on nuisance parameters, which are independent of the misspecification. Using a simulation study, we demonstrate their influence on measures of model fit. We specified a severe misspecification, omitting a second factor, which signifies factorial invalidity. Measures of model fit showed only small misfit because nuisance parameters, magnitude of factor loadings and a balanced/imbalanced number of indicators per factor, also influenced the degree of misfit. Drawing from our results, we discuss challenges in the assessment of factorial validity.


Sensi Journal ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 236-246
Author(s):  
Ilamsyah Ilamsyah ◽  
Yulianto Yulianto ◽  
Tri Vita Febriani

The right and appropriate system of receiving and transferring goods is needed by the company. In the process of receiving and transferring goods from the central warehouse to the branch warehouse at PDAM Tirta Kerta Raharja, Tangerang Regency, which is currently done manually is still ineffective and inaccurate because the Head of Subdivision uses receipt documents, namely PPBP and mutation of goods, namely MPPW in the form of paper as a submission media. The Head of Subdivision enters the data of receipt and mutation of goods manually and requires a relatively long time because at the time of demand for the transfer of goods the Head of Subdivision must check the inventory of goods in the central warehouse first. Therefore, it is necessary to hold a design of information systems for the receipt and transfer of goods from the central warehouse to a web-based branch warehouse that is already database so that it is more effective, efficient and accurate. With the web-based system of receiving and transferring goods that are already datatabed, it can facilitate the Head of Subdivision in inputing data on the receipt and transfer of goods and control of stock inventory so that the Sub Head of Subdivision can do it periodically to make it more effective, efficient and accurate. The method of data collection is done by observing, interviewing and studying literature from various previous studies, while the system analysis method uses the Waterfall method which aims to solve a problem and uses design methods with visual modeling that is object oriented with UML while programming using PHP and MySQL as a database.


2020 ◽  
Vol 10 (2) ◽  
pp. 60-74
Author(s):  
Muhammad Syauqi Mubarok

This article aims to examine and describe the influence of guidance and counseling management on learning discipline. The method used in this research is descriptive analysis method using survey techniques. Data collection techniques that used are documentation studies and field studies. Moreover, the data analysis technique that has been used to answer the research hypothesis is statistical analysis with a path analysis model. The location of the study was at the Ciledug Vocational High School Al-Musaddadiyah Garut, with 85 respondents taking part in the survey. The results of the discussion show that guidance and counseling management has a positive and significant effect on the discipline of learning


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Nuridin, SE., MM. ◽  
Dwi Ardika Prayudha

This research is aimed to examine the influence of brand image and product quality to car purchase decision at PT. Mitsubishi Krama Yudha Motors and Manufacturing. Data analysis method was used, is quantitative analysis, by using validity and reliability test, coefficient of determination, and multiple linear regression analysis. Result of regression equation is: Y = 0,665 + 0,517 X1 + 0,416 X2 Simultaneously testing of brand image variables and product quality to purchase decision, shown by F count equal to 85,955 bigger than F table 3,159 or with sig. F 0.000 is smaller than alpha 0.005. Based on the test results simultaneously, can be seen that the independent variables (brand image and product quality) have a positive and significant impact on the car purchase decision at Mitsubishi cars At PT. Krama Yudha Motors and Manufacturing. Suggestions which can be given for future developments and determinations of policy are, companies should pay attention to brand image, product quality, to make customers more satisfied and keep using Mitsubishi cars as their choice.


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