Influence of Dynamic Viscosity on Automatic Dynamic Balance

2010 ◽  
Vol 164 ◽  
pp. 127-132 ◽  
Author(s):  
Marijonas Bogdevicius ◽  
Jolanta Janutėnienė
Keyword(s):  
Numerical Analysis ◽  
Theoretical Approach ◽  
Dynamic Viscosity ◽  
Lagrange Equation ◽  
Dynamic Balance ◽  
Viscosity Coefficient ◽  
Dynamic Equations ◽  
Linear Character ◽  
Optimal Value ◽  
And Behavior

The paper deals with analysis of dynamic stability and behavior of automatic dynamic balance (ADB) by applying theoretical approach. Differential equations of the considered system were established using Lagrange equation. Numerical analysis of the dynamic equations was performed and influence of dynamic viscosity coefficient on self-balancing process was estimated. It is demonstrated that the balancing time decreases in non-linear character. The optimal value of dynamic viscosity for achieving minimal balancing time can be determined for the analyzed system.

An Application of the Dynamic Balance Equation

2001 ◽  
Author(s):  
Ernest S. Geskin
Keyword(s):  
Energy Balance ◽  
Thermodynamic Functions ◽  
Balance Equation ◽  
Dynamic Balance ◽  
Dynamic Equations ◽  
Additional Information

Abstract The Onsager formalism (generalized fluxes, sources and variables) is used to construct the dynamic balance equation. Previously this equation has been applied to the investigation of energy balance, which includes all interactions between a system and the environment. In this paper the work and non-work interactions are discussed separately. The corresponding forms of the generic balance equation are considered and the dynamic balances of the representative variables ( P V ¯ and enthalpy) are examined. It is shown that the equilibrium relations constitute particular cases of the constructed equations. At the same time the dynamic equations also reveal additional information about a system in question, for example, the developed equations determine the available work of a non-steady process. The paper demonstrates that the dynamic thermodynamic functions constitute an effective tool for systems description.

Study of methods for estimating the viscosity coefficient of metals

2021 ◽  
Author(s):  
S.V. Serikov ◽  
I.K. Ustinov ◽  
O.V. Sulina
Keyword(s):  
Dynamic Viscosity ◽  
Theoretical Study ◽  
Human Life ◽  
Viscosity Coefficient ◽  
Practical Significance ◽  
Accurate Assessment ◽  
Viscosity Coefficients ◽  
Dynamic Yield Strength ◽  
Dynamic Yield ◽  
Problem Setting

Problem setting. The coefficient of dynamic viscosity of metals is used in many branches of human life, but its search, for a more accurate assessment and interpretation, is currently insufficiently studied due to the variety of its application [1-4], as well as due to the uncertainty of the constant parameters of the environment in which it is applied or investigated. Target. Consider a number of known methods for estimating the viscosity coefficients of metals at different ranges of strain patterns. Results. The methods considered for estimating the viscosity coefficient of metals, during their scientific and theoretical study, did not give an unambiguous answer for determining the viscosity of metals. Practical significance. Further study of the dynamic yield strength and the dynamic viscosity coefficient of metals is necessary to achieve more complete results of the method of evaluating the viscosity coefficient of metals.

Landing efficiency control of a six-degree-of-freedom aircraft model with magnetorheological dampers: Part 1—Modeling

2020 ◽  
pp. 1045389X2094257
Author(s):  
Byung-Hyuk Kang ◽  
Ji-Young Yoon ◽  
Gi-Woo Kim ◽  
Seung-Bok Choi
Keyword(s):  
Lagrange Equation ◽  
Degree Of Freedom ◽  
Magnetorheological Damper ◽  
Dynamic Equations ◽  
Design Parameters ◽  
Coordinate Frame ◽  
Aircraft Model ◽  
Efficiency Control ◽  
Six Degree Of Freedom ◽  
Principal Design

This work presents landing efficiency control of a six-degree-of-freedom aircraft model, which has a controllable landing gear system with magnetorheological damper. Due to lengthy contents, this work is divided into two parts. In Part 1, both the kinematic and dynamic equations of the six-degree-of-freedom aircraft model are derived. After determining the principal design parameters of magnetorheological damper based on commercial Beechcraft Baron B55 (passive oleo-strut type) damper, the kinematic equations are derived using the aircraft body coordinate frame and homogeneous coordinates of the reference frame, while the dynamic equations are derived using Euler–Lagrange equation to represent the heave, roll, and pitch motions of the aircraft model. In Part 2, the landing performance based on landing efficiencies is analyzed through the landing motions using various controllers.

scholarly journals Numerical Analysis of the Ballistic Performance and Behavior of STF-Impregnated Multi-layer Fabrics

2016 ◽  
Vol 19 (3) ◽  
pp. 330-338
Author(s):  
Sang Ho Mun ◽  
Kwon Joong Son ◽  
Hee Keun Cho ◽  
Jong Kyoo Park ◽  
Euigyung Jeong ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Ballistic Performance ◽  
And Behavior

scholarly journals TAKING INTO ACCOUNT DEPENDENCE OF VISCOSITY COEFFICIENT ON TEMPERATURE DURING VAPOR CONDENSATION ON A VERTICAL WALL

2020 ◽  
Vol 63 (5) ◽  
pp. 94-101
Author(s):  
Aleksandr I. Moshinskiy ◽  
Pavel G. Ganin ◽  
Alla V. Markova ◽  
Larisa N. Rubtsova ◽  
Vladislav V. Sorokin
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchange ◽  
Transfer Coefficient ◽  
Dynamic Viscosity ◽  
Viscosity Coefficient ◽  
Vapor Condensation ◽  
Condensation Temperature ◽  
Heat Exchange Equipment ◽  
The Heat Transfer Coefficient

In the present study, the problem of vapor condensation on a flat vertical surface is investigated in the case of an arbitrary dependence of the dynamic viscosity coefficient on temperature according to a fairly general law. At a constant value of this coefficient and other characteristics of a condensing liquid (heat conductivity coefficient, density) this task was considered by Nusselt in a constant gravitational field. The results obtained by Nusselt formed the basis (with certain modifications) for the computational practice of heat exchange equipment of chemical technology in the presence of steam condensation of any heat carrier. Formation of a condensate film occurs due to heat transfer through the liquid film, vapor condensation at the outer edge of the film and the flow of liquid along the surface. The article generalizes the Nusselt theory for the heat transfer coefficient under the indicated conditions, and as a result, convenient calculation formulas for the heat transfer coefficient, which are necessary to describe the operation of heat and mass exchange equipment. Approximate relations are proposed for calculating the dynamic viscosity coefficient, which are useful for calculating film flow on a flat surface. A comparison is made with the previously used ratios in an approximate manner taking into account the dependence of viscosity coefficient on temperature. When in technical applications one wants to determine the average value of two parameters, which are then used to calculate certain characteristics of a process, then, traditionally, the average of these parameters is considered. This article shows that by simplifying the dependence of the effective dynamic viscosity coefficient, more accurate results are obtained by dividing the interval of the width of the current film in the ratio of three to one, where three fourths refer to the wall temperature, and one fourth to the condensation temperature. The analytical dependencies presented in this paper can be used for practical calculations of the heat exchange equipment.

Dynamic investigation of a spatial multi-body mechanism considering joint clearance and friction based on coordinate partitioning method

2021 ◽  
pp. 095440622110255
Author(s):  
Gao Hua ◽  
Zhai Jingyu ◽  
Zhang Hao ◽  
Han Qingkai ◽  
Liu Jinguo
Keyword(s):  
Lagrange Equation ◽  
Contact Point ◽  
Stable State ◽  
Constraint Equation ◽  
Friction Model ◽  
Dynamic Equations ◽  
Joint Clearance ◽  
Equivalent Damping ◽  
Equivalent Damping Coefficient ◽  
Coordinate Partitioning

The dynamic response of the model, which is the series connection of a planar four-bar mechanism and a spatial RSSR mechanism, is analyzed considering revolute joint clearance and friction. A non-holonomic constraint equation is proposed to solve the Euler angles. The dynamic equations are established by combining the Lagrange equation with the modified contact model and the LuGre friction model. A dynamic solution program based on the coordinate partitioning method is designed to solve the dynamic equations. The paper verifies the correctness and applicability of the solution program by comparing the numerical calculation results with Adams simulation. Compared with the results of eccentricity, it is found that the maximum penetration is very sensitive to the change of the slider speed rather than the clearance. The equivalent damping coefficient proposed by authors not only represents whether a collision occurs, but reflects the hysteresis caused by damping. The macroscopic manifestation of the up and down oscillation of eccentricity is the swing of the contact point. Besides, the system quickly changes from the collision into the stable state due to considering friction, and the peak value of each collision reduces greatly. Therefore, when the clearance is unavoidable, the clearance joint should be coated with a material with a large friction coefficient and not easy to wear.

DELTA-PLAN-ES—THE INTERACTIVE SYSTEM OF NUMERICAL ANALYSIS OF IMPROPER LINEAR PROGRAMS

1993 ◽  
Vol 03 (04) ◽  
pp. 429-438
Author(s):  
I.I. EREMIN ◽  
L.D. POPOV
Keyword(s):  
Numerical Analysis ◽  
Linear Program ◽  
Interactive System ◽  
Linear Programs ◽  
Feasible Set ◽  
The Real ◽  
Optimal Value

A linear program is said to be improper if its feasible set is empty or its optimal value is infinite. Improper programs appear as a result of inaccuracy of information, of excessive simplification, of considering some restrictions as unchangeable, etc. Moreover, a contradictory model may fit the real contradictions adequately, and the ways of transforming it into a noncontradictory one (the ways of correcting it) may correspond to real procedures of solving these contradictions. The paper describes the DELTA-PLAN-ES interactive system for numerical analysis of improper linear programs. The system is designed for Rjad-2 ES computers.

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