Approach for determination of objective characteristic parameters to predict vehicle vibrations caused by powertrain

2014 ◽  
pp. 879-891
Author(s):  
Rui Cai ◽  
R. Spengler ◽  
C. Olfens ◽  
Albert Albers ◽  
M. Behrendt
Keyword(s):  
Characteristic Parameters

scholarly journals SIMULATION TESTS OF EXTINGUISHING PROCESS USING MIST NOZZLES WITH APPLICATION OF HYBRID FIRE MODEL

2016 ◽  
Vol 22 (4) ◽  
pp. 573-583 ◽  
Author(s):  
Jerzy GAŁAJ ◽  
Marek KONECKI ◽  
Ritoldas ŠUKYS
Keyword(s):  
Heat Flux ◽  
Computer Model ◽  
Input Data ◽  
Elementary Cell ◽  
Characteristic Parameters ◽  
Computational Cell ◽  
Fire Model ◽  
Fire Extinguishing ◽  
Unique Approach

The article presents a computer model of the fire extinguishing process using mist nozzles. A previously developed hybrid fire model was used for this purpose. Assumptions and relationships were given to represent a math­ematical model of extinguishing process, which comprises a unique approach to the determination of sprinkling area in an elementary cell of field fire model. A description of simulation tests of the model was given for several different input data, differing by mean diameters of droplets. This enabled a study of their effects on such output parameters as received heat flux, temperature and rate of its growth. For one selected computational cell located on the axis of the nozzle at floor level having the coordinates [10, 10, 1], the obtained results were presented in the form of heat flux and temperature. To simplify the analysis, characteristic parameters of particular curves were listed in the table. Conclusions formulated on the basis of results obtained during tests were specified at the end of work. They confirmed the expected regularity assuming that the extinguishing process was more effective in the case of droplets of a smaller diameter and greater sprinkling intensity. This allows assessing the degree, to which these stream parameters affect the extinguishing effectiveness.

Diagnosis of the Operation of Power Plants

2007 ◽  
Author(s):  
Jose´ Miguel Gonza´lez-Santalo´ ◽  
Abigail Gonza´lez-Di´az ◽  
Carlos Alberto Marin˜o-Lo´pez
Keyword(s):  
Power Plants ◽  
Environmental Changes ◽  
Environmental Parameters ◽  
Combined Cycle ◽  
Characteristic Parameters ◽  
Operating Variables ◽  
Design Values ◽  
The Individual ◽  
The Impact

A system was developed to diagnose the operation of combined cycle power plants and to determine, when deviations are found, which components are causing the deviations and the impact of each component deviation. The system works by comparing the values of the actual operating variables with some reference values that are calculated by a model that was adjusted to the design heat balances. The model can use the actual values of the environmental parameters as well as the design values, so the effect of environmental changes can be quantified and separated. The determination of the individual equipment impacts is done by adjusting the equipment parameters in order to reproduce the values of the measured variables. The adjustment is done by varying the values of the characteristic parameters of the equipment in order to minimize the sum of the squares of the differences between the values of the measured variables and the calculated values from the model.

Determination of the Equation of State of Polyisobutylene

1969 ◽  
Vol 42 (5) ◽  
pp. 1409-1411
Author(s):  
B. E. Eichinger ◽  
P. J. Flory
Keyword(s):  
Thermal Expansion ◽  
Equation Of State ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Pressure Coefficient ◽  
Experimental Results ◽  
Characteristic Parameters ◽  
Thermal Pressure

Abstract The density, thermal expansion coefficient, and thermal pressure coefficient for polyisobutylene of mol wt 40,000 have been accurately determined from 0 to 150°. Results are compared with the reduced equation of state employed in the theory of solutions. The characteristic parameters v*, T*, and p* required for the treatment of polyisobutylene solutions are obtained from the experimental results.

Four Parameter Inverse Characterization of Fractal Surfaces

2010 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios Iliopoulos
Keyword(s):  
Synthetic Data ◽  
Parametric Representation ◽  
Optimization Method ◽  
Objective Functions ◽  
Characteristic Parameters ◽  
Numerical Application ◽  
Fractal Surfaces ◽  
Deformable Materials

Motivated by the need to determine the mechanical, electrical and thermal properties of contact surfaces between deformable materials that conduct electricity and heat, we are presenting here a method for characterizing certain topological characteristics of rough surfaces. The inverse identification of a set of parameters associated with the parametric representation of any rough surface based on profilometric data is described in contrast with the standard one parameter approaches. The description of the surface topography parametrization is first given in terms of a function that enables the generation of synthetic data. Objective functions are created based on both the profilometric evaluations of the parametric representation of the surface as well as its power spectrum. A statistical Monte Carlo based optimization method is implemented for determining the characteristic parameters needed for further analysis that leads to the determination of other physical properties of the surface. Numerical application of the method validates the efficiency and the accuracy of the proposed approach.

scholarly journals Determination of the characteristic parameters in the special collinear space in the general case

2007 ◽  
Vol 5 (1) ◽  
pp. 49-59
Author(s):  
Sonja Krasic ◽  
Miroslav Markovic
Keyword(s):  
Projective Space ◽  
Projective Geometry ◽  
Descriptive Geometry ◽  
Characteristic Parameters ◽  
Straight Lines ◽  
Structural Methods

The projective space consists of the finitely and infinitely distant elements. The special collinear spaces in the general case, are set with five pairs of biunivocally associated points, so the quadrangle in the first space obtained by the three principal and one penetration point of the remaining two through the plane of the first three identical or similar to the associated quadrangle obtained in the same way in the second space. In order to associate two special collinear spaces, it is necessary to determine the following characteristic parameters: vanishing planes, space axes (principal normal lines), foci (apexes of the associated identical bundles of straight lines) and directrix plane (associated identical fields of points). The paper is based on constructive processing of the special collinear spaces in the general case. The structural methods which are used are Descriptive Geometry (a pair of Mange's projections) and Projective geometry.

scholarly journals Determination of characteristic Parameters of masonry Structures via Operational Modal Analysis

2019 ◽  
Vol 12 (3) ◽  
Author(s):  
Ali Koçak ◽  
Burak Toydemir ◽  
Melih Bulgur
Keyword(s):  
Modal Analysis ◽  
Operational Modal Analysis ◽  
Physical Models ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Model Parameters ◽  
Masonry Structures ◽  
Characteristic Parameters ◽  
Characteristic Model

Commonly, material and vibration characteristics of masonry structures remain uncertain in the evaluation of existing structures under external loads such as earthquake, heat, wind, etc. In addition, determination of compressive and tensile strength of a masonry walls is not straightforward. However, it is very important to know the characteristic parameters such as eigen values, periods and mode shapes of a structure beforehand in order to create accurate and reliable physical models. Since each historical structure has its own unique wall and bearing characteristics, it is not possible to accept random initial values for the bearing capacity and other parameters of the structure. Besides, conducting vertical and lateral loading experiments is costly and time consuming. An alternative way to determine these parameters that govern the structural behavior is to carry out experimental vibration tests using accelerometers. This method, which is also called as Operational Modal Analysis (OMA), is used to obtain the free and forced vibration response of structures by experimental means and to determine the modal parameters of the structure. OMA is very important for the appropriate use of an analysis method and the model parameters used in the analysis. In this study, two masonry buildings, one of which is historical, are discussed and the modal parameters of buildings are determined experimentally with OMA. Characteristic values obtained from OMA were compared with the three dimensional finite element method by adjusting characteristic model parameters.

Sign in / Sign up

Export Citation Format

Share Document