On the Relationship Between Added Mass and Added Damping

2002 ◽  
Author(s):  
H. G. D. Goyder
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Strong Dependence ◽  
Fluid Pressure ◽  
Theoretical Models ◽  
Added Mass ◽  
Measured Data ◽  
Interesting Consequence ◽  
Phase Angles ◽  
The Relationship

A surprising relationship exists between the amplitude and phase of a vibrating system. For an item vibrating in a fluid flow the phase of the fluid pressure (relative to the motion of the structure) can be deduced from the amplitude of the pressure. This strong dependence of the phase on the amplitude provides a means for checking the correctness of measured data and severely constrains the form that a mathematical model can take. The relationship between amplitude and phase is completely general and the paper gives various examples from theoretical models and experimental data. One interesting consequence of this relationship follows from the observation that phase angles only exist because of damping. Hence damping, due to the fluid, is linked to added mass.

scholarly journals CORRELATIONS IN MULTI-LOCUS GENETIC SYSTEMS: A MATHEMATICAL MODEL

Genetics ◽  
1974 ◽  
Vol 77 (3) ◽  
pp. 591-605
Author(s):  
C T Falk ◽  
H Falk
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Linear Combination ◽  
Genetic Model ◽  
Theoretical Models ◽  
Spin Model ◽  
Entire System ◽  
Additional Experimental Data ◽  
Genetic Systems

ABSTRACT A spin model with parallels to a multi-locus genetic model is presented which makes it possible to calculate the correlation between allelic states at any two loci in a population at equilibrium. The main features are: (1) The decay of correlation with distance may be expressed essentially as a linear combination of two exponentials, one of which dominates when the two loci are sufficiently far apart. (2) The correlation between two loci a specified distance apart is increased as the number of loci in the entire system increases. The results are compared with those of other theoretical models and discussed in the light of available experimental data. Possible ways of generalizing the model are outlined. However, additional experimental data is clearly needed to indicate the genetic relevance of work of this nature.

Investigation on Silicon-Glass Electrostatic Bonding Time Experiment

2011 ◽  
Vol 483 ◽  
pp. 78-82
Author(s):  
Xiao Wei Liu ◽  
Jia Lu Tang ◽  
Rong Yan Chuai ◽  
Hai Feng Zhang ◽  
Xi Lian Wang
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Bonding Process ◽  
Bonding Time ◽  
Relationship Of ◽  
The Mathematical Model ◽  
The Relationship ◽  
Electrostatic Bonding

In this paper, we make a detail analysis of some factors, which affects the electrostatic bonding process. According to the electrical properties of glass, combined with the principle of electrostatic bonding, we analysed the relationship of critical bonding time, voltage and temperature as well as the factors which affect electrostatic bonding. Then we come up with the mathematical model of the intensity and temperature of electrostatic bonding. In accordance with the above-mentioned formula and the experimental data, we can get the following conclusions: the intensity of electrostatic bonding is much greater between 280°C to 370°C; the best temperature for this bonding is about 350°C; however, when the temperature is below 280°C,the intensity of electrostatic bonding is lower due to the great impact of particles under low temperature; but when the temperature is higher than 370°C,the mismatch of coefficient of thermal expansion of silicon and glass gets larger, then as a result, the intensity of this bonding has a significant decrease with the increasing of temperature.

Assessing the characteristic between length of hypoxic exposure and serum erythropoietin levels

1990 ◽  
Vol 258 (4) ◽  
pp. R1016-R1021
Author(s):  
C. Cahan ◽  
P. L. Hoekje ◽  
E. Goldwasser ◽  
M. J. Decker ◽  
K. P. Strohl
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Hypobaric Hypoxia ◽  
Prolonged Exposure ◽  
Serum Levels ◽  
Significant Rise ◽  
Hypoxic Exposure ◽  
Long Evans ◽  
The Relationship ◽  
Serum Erythropoietin

We examined the relationship between the duration of hypoxic exposure and serum erythropoietin (EPO) production. Adult male Long-Evans rats were exposed to hypobaric hypoxia (HH = 0.5 atm) for a period of 15 min to 20 days. Serum for EPO by radioimmunoassay was collected immediately, 1 or 2 h after HH exposure. A significant rise in EPO levels occurred 1 h after a 30-min HH exposure that was not sustained 2 h after termination. One hour of HH exposure resulted in increased EPO levels 1 h after termination of exposure and further increased levels 2 h after termination of exposure. With prolonged exposure, serum levels remained elevated at 6 and 20 days, despite the development of polycythemia. We concluded that the hypoxic stimulus for elevation of serum EPO could be as short as 30 min and that EPO levels remained elevated after chronic HH. The experimental data were consistent with a mathematical model in which stimulated EPO production was proportional to the time of HH stimulus.

scholarly journals ANALYSIS OF INTENSIVELY BLASTED ELECTRIC ARC BURNING IN THE ARC HEATER'S ANODE CHANNEL

2016 ◽  
Vol 56 (5) ◽  
pp. 395-401 ◽  
Author(s):  
Josef Senk ◽  
Ivana Jakubova ◽  
Ilona Laznickova
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Power Loss ◽  
Gas Flow ◽  
Measured Data ◽  
Electric Arc ◽  
Gas Flow Rate ◽  
Voltage Distribution ◽  
Current Voltage ◽  
Arc Heater

The paper deals with the description of the intensively blasted electric arc burning in Ar in the anode channel of the arc heater operated under various conditions. Directly measured experimental data (current, voltage, gas flow rate, power loss) characterize the operation of the device as a whole, but important parameters describing the electric arc inside (its geometry, temperature and voltage distribution) must be revealed using a mathematical model of the arc. An updated version of the model is introduced and used for analysis of two exemplary sets of measured data. The results are given in figures and commented.

scholarly journals Effect of an Added Mass On the Vibration Characteristics for Raster Scanning of a Cantilevered Optical Fiber

2021 ◽  
Author(s):  
Kelli Kiekens ◽  
David Vega ◽  
Harrison Thurgood ◽  
Dominique Galvez ◽  
Davis McGregor ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Optical Fiber ◽  
Resonant Frequency ◽  
Optical Fibers ◽  
Added Mass ◽  
Measured Data ◽  
Intermediate Mass ◽  
Resonant Frequencies ◽  
Raster Scanning ◽  
Cantilevered Beam

Abstract Piezoelectric tube actuators with cantilevered optical fibers have enabled the miniaturization of scanning image acquisition techniques for endoscopic implementation. To achieve raster scanning for such a miniaturized system, the first resonant frequency should be on the order of 10's of Hz. We explore adding a mass at an intermediate location along the length of the fiber to alter the resonant frequencies of the system. We provide a mathematical model to predict resonant frequencies for a cantilevered beam with an intermediate mass. The theoretical and measured data match well for various fiber lengths, mass sizes, and mass attachment locations along the fiber.

Study on Similarity of Pump Blade Adjusting Performances

2013 ◽  
Author(s):  
Yuan Yao ◽  
Liu Chao
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Model Test ◽  
Power Flow ◽  
Measured Data ◽  
Least Square ◽  
Flow Index ◽  
Blade Angle ◽  
Flow Curves ◽  
Pump Impeller

Through analyzing the change in velocity triangles at the inlet and exit of pump impeller with blade adjusting, and the flow behaviors in the pump passage the pump blade adjusting formulae were derived which reflect the similarity of flow and pumping head with the blade angles adjusted. Based on the experimental data of pump performances a mathematical model was developed to calculate the flow index and head index of the formulae. The objective function is a minimized the least square sum of the errors of the formulae’s calculation and the test data. The formulae were applied to three model pumps. The results show that the errors between calculated and measured data are 0.0228, 0.0116%, 0.0123 respectively, and all the head-flow curves (H-Q) and the power-flow curves (P-Q) agree well with the measured data from model test. Therefore, the derived formulae are featured with good similarity in pump performances for change blade angle, which can be applicable to the performances conversion and prediction of pump with blade adjusting.

scholarly journals Lean management as the innovative technology of an enterprise

2021 ◽  
Vol 116 ◽  
pp. 00008
Author(s):  
Sergey Komarov ◽  
Mariya Kudina ◽  
Gulnaz Suzdaleva ◽  
Dmitriy Shishkin
Keyword(s):  
Mathematical Model ◽  
Life Cycle ◽  
Theoretical Models ◽  
Innovative Activity ◽  
Innovative Technology ◽  
Future Research ◽  
Lean Management ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

The paper is devoted to the problem of management of innovative activity of an enterprise on the basis of Lean technology. The study shows that there are no generally accepted theoretical models for understanding this relationship and its unambiguous assessment. The paper discusses a pilot study of the relationship of Lean management factors and innovative activity for large Russian enterprises taking into account their life cycle and type of innovation. The results of the study demonstrate the correlation between lean production and innovative activity of the enterprise. The conclusions on the impact of the type of enterprise (business), the stage of its life cycle and the type of innovation on this relationship are innovative and important. The study is aimed at testing the methodology of future research, the purpose of which is to build a mathematical model of such a relationship.

scholarly journals CONSTRUCTION OF MATHEMATICAL MODELS USING THE METHODS OF CORRELATION AND REGRESSION ANALYSIS

2021 ◽  
pp. 29-36
Author(s):  
Olga Prishchenko ◽  
Nadezhda Cheremskaya ◽  
Tetyana Chernogor
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Regression Analysis ◽  
Functional Relationship ◽  
Functional Dependence ◽  
Mathematical Expression ◽  
Regression Equation ◽  
Statistical Hypothesis ◽  
Correlation And Regression Analysis ◽  
The Relationship

The article discusses the construction of a mathematical model using the methods of correlation and regression analysis in determining the functional relationship between the quantities. When conducting an experiment, it is often necessary to establish the interdependence between two or more quantities in order to obtain an empirical formula. In some cases, this is a simple task, because these connections are almost obvious or known in advance. As a rule, to establish the relationship between different indicators, factors and characteristics is not a trivial task. There is a need to use some hypothesis in the form of functional dependence. In other words, it is necessary to replace this functional dependence with a fairly simple mathematical expression. Such a mathematical expression can be a linear equation or a polynomial. In order to use such experimental data to determine such a mathematical or functional relationship between variables, the methods of correlation and regression analysis are used. Correlation analysis provides an answer to the statistical hypothesis of the absence or presence of a relationship between variables with some predetermined confidence probability. Determination of the functional dependence between different values on their experimental values is carried out using regression analysis. It is based on the well-known method of least squares. Proposing one or another regression equation, the researcher determines both the very existence of the relationship between variables and its mathematical form. Regression analysis considers the relationship between the dependent quantity and non-dependent variables. This relationship is represented using a mathematical model, that is, an equation that connects the dependent and independent variables. Processing of experimental data using correlation and regression analysis allows us to build a statistical mathematical model in the form of a regression equation. Thus, the methods of correlation and regression analysis are closely related.

scholarly journals СРАВНИТЕЛЬНЫЙ АНАЛИЗ МЕТОДОВ РАСЧЁТА АМПЛИТУД КОЛЕБАНИЙ ДАВЛЕНИЯ, СОЗДАВАЕМЫХ КАВИТАЦИОННЫМ ГЕНЕРАТОРОМ

2018 ◽  
pp. 58-68
Author(s):  
Юрий Алексеевич Жулай ◽  
Юрий Александрович Кваша ◽  
Алексей Дмитриевич Николаев
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Specific Energy Consumption ◽  
Fluid Pressure ◽  
Experimental Studies ◽  
Industrial Plant ◽  
Design Stage ◽  
Oscillatory Process ◽  
Pressure Oscillations ◽  
Element Discretization

One of the devices implementing energy-saving technologies is a Venturi tube of special geometry, called the cavitations generator of fluid pressure oscillation (hereinafter referred to as the generator). It converts the steady-state flow of process fluid into a discrete-impulse flow of increased power and has the simplicity of manufacturing that lacks moving parts, does not require additional energy sources and seamlessly fits into existing equipment. The practical use of the generator in engineering, metallurgy, the chemical industry and in mining, can reduce the specific energy consumption by up to 50%. The purpose of this paper is a comparative analysis of the existing methods for calculating the amplitudes of pressure oscillations generated by the generator and the choice of a method that makes it possible to determine the amplitudes with an acceptable accuracy. The technique is based on the determination by various computation methods of peak-to-peak values of the fluid pressure from the cavitations flow regime. The results are presented in the form of calculated dependences of the of peak-to-peak oscillation values of the fluid pressure on the value of the cavitations parameter and their comparison with the experimental data. Scientific novelty. It is established that the method using the finite-element discretization of the generator and outlet pipeline construction with fluid moving in it satisfactorily describes the parameters of the oscillatory process in various elements of the hydraulic system. However, the model requires some correction in the part of the description of the basic dependencies describing the dynamics of the cavitations flow in the generator, if it is necessary to more agreement with the experimental data. This model is convenient for carrying out multi-purpose research works, including experimental data correction, but its application for engineering calculations causes certain difficulties in the part of programming and the length of preparation for the calculations. The refined linear mathematical model of the generator makes it possible to obtain a quantitative agreement between the experimental and theoretical dependences of the amplitude of fluid pressure oscillations on the cavitations parameter by engineering methods. The practical significance of the results obtained is that the refined linear mathematical model of the generator makes it possible to establish at the design stage a rational regime of the hydroimpulse action of the generator (the peak-to-peakvalues of fluid pressure oscillations) at a certain pressure in the process pipeline of an industrial plant and does not require additional experimental studies

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