scholarly journals Four-dimensional equation of motion for viscous compressible and charged fluid with regard to the acceleration field, pressure field and dissipation field

2015 ◽  
Vol 18 (1) ◽  
pp. 13 ◽  
Author(s):  
Sergey G. Fedosin
Keyword(s):  
Pressure Field ◽  
Equation Of Motion ◽  
Charged Fluid ◽  
Acceleration Field ◽  
Dimensional Equation

Large Amplitude Pulsatile Water Flow Across an Orifice

1975 ◽  
Vol 97 (1) ◽  
pp. 92-95 ◽  
Author(s):  
E. L. Yellin ◽  
C. S. Peskin
Keyword(s):  
Large Amplitude ◽  
Heart Valves ◽  
Equation Of Motion ◽  
Separated Flows ◽  
Prosthetic Heart Valves ◽  
One Dimensional ◽  
Water Flows ◽  
Lumped Parameter ◽  
Dimensional Equation ◽  
The One

The pressure-flow relations of large amplitude pulsatile water flows across an orifice have been investigated theoretically and experimentally. By retaining the unsteady term in the one-dimensional equation of motion, and by allowing the jet area to be a function of distance in the continuity equation, a lumped parameter relationship between pressure drop and flow has been developed which reflects the influence of inertia and dissipation. The results are applicable to the analysis of natural and prosthetic heart valves under normal and pathologic conditions. Within the physiologically possible conditions of frequency and flow rate, unsteady separated flows exhibit the same energy losses as comparable steady separated flows. Thus, the flow is quasi-steady, even when the waveforms and temporal relations indicate a significant inertial influence.

Nondimensional analysis of a two-dimensional shear deformable beam in absolute nodal coordinate formulation

2017 ◽  
Vol 232 (7) ◽  
pp. 1236-1246 ◽  
Author(s):  
Kun-Woo Kim ◽  
Jae-Wook Lee ◽  
Jin-Seok Jang ◽  
Joo-Young Oh ◽  
Ji-Heon Kang ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Absolute Nodal Coordinate Formulation ◽  
Equation Of Motion ◽  
Central Processing Unit ◽  
Processing Unit ◽  
Two Dimensional ◽  
Absolute Nodal Coordinate ◽  
Central Processing ◽  
Dimensional Equation ◽  
Shear Deformable

Absolute nodal-coordinate formulation is a technique that was developed in 1996 for expressing the large rotation and deformation of a flexible body. It utilizes global slopes without a finite rotation in order to define nodal coordinates. The method has a shortcoming in that the central processing unit time increases because of increases in the degrees of freedom. In particular, when considering the deformation of a cross section, the shortcoming due to the increase in the degrees of freedom becomes clear. Therefore, in the present research, the dimensional equation of motion concerning a two-dimensional shear deformable beam, developed by Omar and Shabana, is converted into a nondimensional equation of motion in order to reduce the central processing unit time. By utilizing an example of a cantilever beam, wherein an exact solution for the static deflection exists, the nondimensional equation of motion was verified. Moreover, by using an example of a free-falling flexible pendulum, the efficiency of the nondimensional equation of motion gained by increasing the number of elements was compared with that of the dimensional equation of motion.

scholarly journals The Generalized Poynting Theorem for the General Field and Solution of the 4/3 Problem

2019 ◽  
Vol 14 ◽  
pp. 19-40
Author(s):  
Sergey G. Fedosin
Keyword(s):  
Pressure Field ◽  
Mass Density ◽  
Relativistic Energy ◽  
Equilibrium System ◽  
Gravitational Fields ◽  
Acceleration Field ◽  
System Of Particles ◽  
Field Coefficient ◽  
The Given ◽  
Poynting Theorem

The generalized Poynting theorem is applied to the equilibrium system of particles, both inside and outside the system. The particles are bound to each other by means of the electromagnetic and gravitational fields, acceleration field and pressure field. As a result, the correlation is found between the acceleration field coefficient, the pressure field coefficient, the gravitational constant and the vacuum permittivity. This correlation also depends on the ratio of the charge density to the mass density of the particles inside the sphere. Due to the correlation between the given field coefficients the 4/3 problem is solved and the expression for the relativistic energy of the system is refined.

Stability analysis of a rigid rotor supported by two-lobe hydrodynamic journal bearings operating with a non-Newtonian lubricant

2018 ◽  
Vol 233 (6) ◽  
pp. 884-898 ◽  
Author(s):  
Saurabh K Yadav ◽  
Arvind K Rajput ◽  
Nathi Ram ◽  
Satish C Sharma
Keyword(s):  
Reynolds Equation ◽  
Pressure Field ◽  
Equation Of Motion ◽  
Journal Bearings ◽  
Rigid Rotor ◽  
Linear Finite Element ◽  
Runge Kutta Method ◽  
The Stability ◽  
Ellipticity Ratio ◽  
Bearing System

In the present work, an investigation has been performed on a rigid rotor supported by two-lobe journal bearings operating with a non-Newtonian lubricant. The governing Reynolds equation for pressure field is solved by using non-linear finite element method. Further to study the dynamic stability of the bearing system, governing equation of motion for the rotor position is solved by fourth order Runge–Kutta method. Bifurcation and Poincaré maps of two-lobe bearings are presented for different values of the non-Newtonian parameter and bearing ellipticity ratio. The numerical results illustrate that the ellipticity of a bearing with a dilatant lubricant improve the stability of the rotordynamic system.

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