Analytic determination of the target function gradient for an implicit form of the equations of state of a dynamic system

1978 ◽  
Vol 18 (6) ◽  
pp. 249-252
Author(s):  
A.A. Kuraev
Keyword(s):  
Dynamic System ◽  
Equations Of State ◽  
Target Function ◽  
Analytic Determination ◽  
Implicit Form

Analytic Determination of Wrench Closure Workspace of Spatial Cable Driven Parallel Mechanisms

2015 ◽  
Author(s):  
Zhiyu Sheng ◽  
Joon-Hyuk Park ◽  
Paul Stegall ◽  
Sunil K. Agrawal
Keyword(s):  
Simulation Study ◽  
Null Space ◽  
Boundary Surface ◽  
Parallel Mechanisms ◽  
Analytic Determination ◽  
Structure Matrix ◽  
Feasible Solutions

This paper proposes an efficient way of determining analytically the Wrench Closure Workspace (WCW) of spatial redundant cable-driven parallel mechanisms (CDPM). The method builds upon the boundary surface equations obtained from the null space of the structure matrix of CDPM. The set of feasible solutions is obtained that satisfies positive tension in the cables. This method was applied to characterize the WCW of spatial CDPM which has redundancy of 1 or 2. A simulation study was carried out to validate the accuracy and efficiency of the method. Several advantages over conventional approaches for determining the WCW were identified through simulation.

Technique and results of experimental determination of the compressibility factor of the natural gas

2021 ◽  
pp. 35-40
Author(s):  
Denis Y. Kutovoy ◽  
Igor A. Yatsenko ◽  
Vladimir B. Yavkin ◽  
Aydar N. Mukhametov ◽  
Petr V. Lovtsov ◽  
...  
Keyword(s):  
Natural Gas ◽  
Equations Of State ◽  
Compressibility Factor ◽  
High Accuracy ◽  
State Equations ◽  
Actual Problem ◽  
Temperature Range ◽  
Relative Value ◽  
Compressibility Coefficient

The actual problem of the possibility of using the equations of state for the gas phase of natural gas at temperatures below 250 K is considered. To solve it, the compressibility coefficients of natural gas obtained experimentally with high accuracy are required. The technique was developed and experimental study was carried out of compressibility factor aiming expanding temperature range of the state equations GERG-2004 and AGA8-DC92. The proposed technique is based on the fact that to assess the applicability of the equation of state, it is sufficient to obtain the relative value of the compressibility coefficient and not to determine its absolute value. The technique does not require complex equipment and provides high accuracy. The technique was tested on nitrogen, argon, air and methane. Uncertainty of determination of the compressibility factor is not greater than 0.1 %. For two different compositions of natural gas, obtained experimental data were demonstrated that the equations of state GERG-2004 and AGA8-92DC provide uncertainty of the calculation of the compressibility coefficient within 0.1 % in the temperature range from 220 K to 250 K and pressure below 5 MPa.

Analytic Determination of Slip and Efficiencies of Rolling Contact C.V.T.’s With Experimental Verifications

1986 ◽  
Vol 108 (1) ◽  
pp. 72-76 ◽  
Author(s):  
J. Modrey ◽  
Y. K. Younes
Keyword(s):  
Computer Simulation ◽  
Rolling Contact ◽  
Analytic Determination ◽  
Continuously Variable Transmissions ◽  
Fluid Properties ◽  
Good Guide ◽  
Parallel Tests

Rolling contact continuously variable transmissions (C.V.T.) transmit forces through a highly viscous spot between rolling-slipping contacts. The mechanics of the spot are characterized by complex elastohydrodynamic conditions and fluid properties only partially determinable at the extreme pressures of operation. A computer simulation of the spot mechanics based on extensions of research in less complex elastohydrodynamic situations was developed. Comparisons with parallel tests on a commercial C. V. T. verify that the simulation described in a good guide to design of this class of transmissions.

scholarly journals Modeling of diversification of foreign economic interactions

2018 ◽  
Vol 16 (1) ◽  
pp. 155-165
Author(s):  
Ihor Hroznyi ◽  
Oleh Kuzmak ◽  
Olena Kuzmak ◽  
Olha Rusinova
Keyword(s):  
Dynamic System ◽  
Simulation Model ◽  
Mutual Influence ◽  
Model Development ◽  
Complex Dynamic ◽  
Complex Dynamic System ◽  
World Markets ◽  
Economic Interactions ◽  
Simulation Package

The article developed a basic simulation model of diversification of foreign economic interactions, which makes it possible to assess the mutual influence of key economic indicators and their reaction to changes in the equilibrium in world markets. The peculiarity of the developed model of diversification of foreign economic interactions is its functioning as a complex dynamic system in which many factors are interrelated, and the connections are dynamic. This makes it possible to calculate a simulation model that takes into account hidden and subtle connections. While modeling foreign economic interactions and evaluating the influence of various regulators on them, in addition to the stage of model development itself, mandatory parameterization of this model is proposed, that is, the determination of specific types of dependence between the factors included in the model and the parameters of these dependencies. The implementation of this model can be carried out in any simulation package.

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