TENSOR ANALYSIS OF MAIN DIFFERENTIAL OPERATORS UTILIZED FOR DESCRIPTION OF OCEAN HYDRODYNAMICS IN CURVILINEAR ORTHOGONAL COORDINATE SYSTEM

2019 ◽  
Vol 47 (2) ◽  
pp. 139-171
Author(s):  
V.M. Kamenkovich ◽  
D.A. Nechaev

The paper presents an analysis of tensor expressions in different curvilinear orthogonal coordinate systems. The analysis reveals specific properties of a number of approximated coordinate systems widely used in the studies of ocean dynamics. The paper consists of two parts. The part 1 presents a brief overview of the key definitions and important relations of tensor analysis which are utilized in part 2 of the paper. The part 2 considers invariant representation of different types of vector products, divergence of vector field and divergence of symmetric tensor of rank 2, gradient of a scalar filed, curl of a vector filed. The part 2 also discusses specific properties of the rate-of-strain tensor, general form of the Laplace operator, properties of operator nabla, and general forms of material derivative for scalar and vector fields. The equations for the properties under consideration are derived for the physical components of the corresponding tensors.

2018 ◽  
Vol 193 ◽  
pp. 03022
Author(s):  
Dmitry V. Nesnov

Field theory is widely represented in spherical and cylindrical coordinate systems, since the mathematical apparatus of these coordinate systems has been thoroughly studied. Sources of field with more complex structures require new approaches to their study. The purpose of this research is to adapt the field theory referred to curvilinear coordinates and represent it in normal toroidal coordinates. Another purpose is to develop the foundations of geometric modeling with the use of computer graphics for visualizing the level surfaces. The dependence of normal toroidal coordinates on rectangular Cartesian coordinates and Lame coefficients is shown in this scientific paper. Differential characteristics of scalar and vector fields in normal toroidal coordinates are obtained: scalar and vector field laplacians, divergence, and rotation of vector field. The example shows the technique of modeling the field and its further computer visualization. The technique of reading the internal equation of the surface is presented and the influence of the values of the parameters on the shape of the surface is shown. For the first time, expressions of scalar and vector field characteristics in normal toroidal coordinates are obtained, the fundamentals of geometric modeling of fields with the use of computer graphics tools are developed for the purpose of providing visibility for their study.


Author(s):  
Jian Ge ◽  
Rui Wang ◽  
Haobin Dong ◽  
Huan Liu ◽  
Qianwei Zheng ◽  
...  

2001 ◽  
Vol 16 (23) ◽  
pp. 1479-1486 ◽  
Author(s):  
A. A. BYTSENKO ◽  
A. E. GONÇALVES ◽  
S. ZERBINI

The non-planar contribution to the effective potentials for massless scalar and vector quantum field theories on D-dimensional manifold with p compact noncommutative extra dimensions is evaluated by means of dimensional regularization implemented by zeta function techniques. It is found that, the zeta function associated with the one-loop operator may not be regular at the origin. Thus, the related heat kernel trace has a logarithmic term in the short t asymptotic expansion. Consequences of this fact are briefly discussed.


2016 ◽  
Vol 94 ◽  
pp. 47-67 ◽  
Author(s):  
Alexander J.G. Lunt ◽  
Enrico Salvati ◽  
Lifeng Ma ◽  
Igor P. Dolbyna ◽  
Tee K. Neo ◽  
...  

1991 ◽  
Vol 130 ◽  
pp. 71-74
Author(s):  
A.Z. Dolginov ◽  
N.A. Silant’ev

AbstractA new method for the calculation of kinetic coefficients is presented. This method allows us to obtain the distribution of scalar and vector fields (such as the temperature, the admixture particle number density and the magnetic field) in turbulent cosmic media with any value of S = u0т0/R0. The explicit expression for the “turbulent” diffusivity DT is obtained. In some cases DT becomes negative, implying the clustering of the admixture particles in patches (a local increase of the temperature and magnetic fields). The magnetic α-effect is considered for the case S ~ 1.


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