Analytical Solution of the Navigation Problem on the Orthodromic Trajectory in the Greenwich Coordinate System

2018 ◽  
Vol 53 (S2) ◽  
pp. 133-134
Author(s):  
P. A. Kucherenko ◽  
S. V. Sokolov
Author(s):  
Shuangbiao Liu ◽  
W. Wayne Chen ◽  
Diann Y. Hua

Step bearings are frequently used in industry for better load capacity. Analytical solutions to the Rayleigh step bearing and a rectangular slider with a finite width are available in literature, but none for a fan-shaped thrust step bearing. This study starts with a known solution to the Laplace equation in a cylindrical coordinate system, which is in the form of infinite summation. An analytical solution to pressure is derived in this paper for hydrodynamic lubrication problems encountered in the fan-shaped step bearing. The presented solutions can be useful for designers to maximize bearing performance as well as for researchers to benchmark numerical lubrication models.


Author(s):  
E. Talygin ◽  
G. Kiknadze ◽  
A. Agafonov ◽  
A. Gorodkov

Abstract In previous works it has been proved that the dynamic geometry of the streamlined surface of the flow channel of the heart chambers and main arteries corresponds with a good agreement to the shape of the swirling flow streamlines. The vectorial velocity field of such a flow in a cylindrical coordinate system was described by means of specific analytical solution basing on the potentiality of the longitudinal and radial velocity components. The viscosity of the medium was taken into account only in the expression for the azimuthal velocity component and the significant effect of viscosity was manifested only in a narrow axial region of a swirling jet. The flow described by the above relations is quasipotential, axisymmetric, and convergent. The structural organization of this flow implies the elimination of rupture and stagnation zones, and minimizes the viscous losses. The proximity of the real blood flow under the normal conditions to the specified class of swirling flows allows us to determine the basic properties of the blood flow possessing the high pressure-flow characteristics without stability loss. The blood flow has an external border, and the interaction with the channel wall and between moving fluid elements is weak. These properties of the jet explain the possibility of a balanced blood flow in biologically active boundaries. Violation of the jet properties can lead to the excitation of biologically active components and trigger the corresponding cascade protective and compensatory processes. The evolution of the flow is determined by the time-dependent characteristic functions, which are the frequency characteristics of the rotating jet, as well as functions depending on the dimension of the swirling jet. Previous experimental studies revealed close connection between changes in the characteristic functions and dynamics of the cardiac cycle. Therefore, it is natural to express these functions in analytical form. For these purposes it was necessary to establish the link between these functions and the spatial characteristics of the swirling jet. To solve this problem the analytical solution for the velocity field of a swirling jet was substituted into the Navier-Stokes system and continuity differential equations in a cylindrical coordinate system. As a result, a new system of differential equations was obtained where the characteristic functions could be derived. The solution of these equations allows the identification of time-dependent characteristic functions, and the establishment of a link between the characteristic functions and the spatial coordinates of the swirling jet. This link gives the opportunity to substantiate a theoretical possibility for the modeling of quasipotential viscous flows with a given structure. The definition of characteristic functions makes it possible to obtain the exact solution which allows formalization of the boundary conditions for physical modeling and experimental study of this flow type. Such transformations allow the definition of the conditions supporting renewable swirling blood flow in the transport arterial segment of the circulatory system and provide the basis for new principles of modeling, diagnosis and surgical treatment of circulatory disorders associated with the changes in geometry of the heart and great vessels.


1994 ◽  
Vol 31 (2) ◽  
pp. 303-308 ◽  
Author(s):  
V. Silvestri ◽  
C. Tabib

This technical note describes the analysis of the strain field around a simple pile. The analytical solution is obtained by using a spherical coordinate system of reference. It is shown that the expressions for the various strains are very simple. Streaming motions and octahedral shear strain contours are presented in graphical forms. Key words : simple pile, streaming motion, strain field.


2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Suneet Singh ◽  
Prashant K. Jain ◽  
Rizwan-uddin

An analytical solution has been obtained for the transient problem of three-dimensional multilayer heat conduction in a sphere with layers in the radial direction. The solution procedure can be applied to a hollow sphere or a solid sphere composed of several layers of various materials. In general, the separation of variables applied to 3D spherical coordinates has unique characteristics due to the presence of associated Legendre functions as the eigenfunctions. Moreover, an eigenvalue problem in the azimuthal direction also requires solution; again, its properties are unique owing to periodicity in the azimuthal direction. Therefore, extending existing solutions in 2D spherical coordinates to 3D spherical coordinates is not straightforward. In a spherical coordinate system, one can solve a 3D transient multilayer heat conduction problem without the presence of imaginary eigenvalues. A 2D cylindrical polar coordinate system is the only other case in which such multidimensional problems can be solved without the use of imaginary eigenvalues. The absence of imaginary eigenvalues renders the solution methodology significantly more useful for practical applications. The methodology described can be used for all the three types of boundary conditions in the outer and inner surfaces of the sphere. The solution procedure is demonstrated on an illustrative problem for which results are obtained.


Author(s):  
Dedy A Bilaut ◽  
C Cari ◽  
A Suparmi ◽  
Miftahul Ma’arif

<p class="AbstractEnglish"><strong>Abstract:</strong> The analytical solution of the Schrodinger equation affected by Kratzer potential in Bispherical coordinate system was derived. The separable method was applied to reducing the Schrodinger equation which depends on  into three one-dimensional Schrodinger equations. The Schrodinger equations as the function of  with and without -deformed were solved using the SUSY QM method. The solutions were eigenvalue and eigenfunction of -deformed Schrodinger equation and eigenvalue end eigenfunction of Schrodinger equation with and without q-deformed in Bispherical coordinate system. The energy of the Schrodinger equation with -deformed equals to the Energy of Schrodinger without -deformed since the  parameter becomes to zero.</p><p class="AbstrakIndonesia"><strong>Abstrak:</strong> Solusi analitik dari Persamaan Schrodinger yang dipengaruhi Potensial Kratzer dalam koordinat Bispherical telah berhasil diturunkan. Metode pemisahan variabel digunakan untuk mereduksi persamaan Schrodinger yang bergantung pada  menjadi tiga persamaan Schrodinger satu dimensi. Persamaan Schrodinger fungsi  terdeformasi- dan tidak terdeformasi- diselesaikan menggunakan metode SUSY QM. Solusi yang berhasil didapatkan adalah nilai eigen dan fungsi eigen persamaan Schrodinger, masing-masing untuk sistem terdeformasi- dan yang tidak terdeformasi- dalam koordinat Bispherical. Energi dari persamaan Schrodinger terdeformasi- sama dengan energi dari persamaan Schrodinger yang tidak terdeformasi- ketika  sama dengan nol.</p>


2020 ◽  
Vol 201 ◽  
pp. 01017
Author(s):  
Mikhail Nikolaitchik

An analytical solution is presented to the problem of determining the force effect of lifting vessel (skip) on guides during its movement in the mine shaft. Forces values are obtained using acceleration data from sensors of motion smoothness through monitoring system. The technique developed allows to determine skip force effect on guides along all axes of horizontal coordinate system. A transition from a force to impulse action is provided. The interrelation of force action surges with guides profile deviations is analyzed. The results of this study can be widely used to identify the areas in the mine shaft where emergency could potentially occur.


1999 ◽  
Vol 36 (6) ◽  
pp. 1197-1201 ◽  
Author(s):  
Yee-Chung Jin ◽  
Songlin Ye

An approximate analytical solution is derived for solute transport with monovalent-divalent ion exchange in saturated, steady, groundwater flow. The analytical solution is obtained by simplifying the complicated heterovalent ion exchange. Using a coordinate system that moves at the average solute advection velocity, a solution is obtained by direct integration with given boundary and initial conditions. The results agree well with a numerical solution using the original isotherm. The analytical solution presented is similar to that of monovalent-monovalent exchange, which suggests that a simple ion exchange model may be assumed for approximation.


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