Apparent Resistivity Calculations for Three Two-dimensional Conductivity Models with Vertical Discontinuities

1971 ◽  
Vol 8 (8) ◽  
pp. 961-966 ◽  
Author(s):  
F. W. Jones
Keyword(s):  
Surface Charge ◽  
Numerical Method ◽  
Surface Structure ◽  
Electromagnetic Induction ◽  
Apparent Resistivity ◽  
Two Dimensional ◽  
Near Surface ◽  
A Value ◽  
Surface Contact ◽  
Conductivity Models

Electromagnetic induction in three two-dimensional models of conductors with two regions of different conductivity is considered. Solutions are obtained for both the H-polarization and E-polarization cases by a numerical method. Apparent resistivity as a function of period is plotted for various locations relative to the surface contact. For the H-polarization case, the apparent resistivity values calculated for points near the surface contact are affected by the varying surface charge on the interface between the regions, and a value different from the expected value is obtained. In the E-polarization case the apparent resistivity curves exhibit a "dip" characteristic when the apparent resistivity is calculated for surface points near a shelf or step structure. In both cases the value of apparent resistivity calculated at or near surface contacts between different conducting regions depends greatly on the sub-surface structure.

scholarly journals Analysis of the horizontal two-dimensional near-surface structure of a winter tornadic vortex using high-resolution in situ wind and pressure measurements

2015 ◽  
Vol 120 (12) ◽  
pp. 5879-5894 ◽  
Author(s):  
Ryohei Kato ◽  
Kenichi Kusunoki ◽  
Eiichi Sato ◽  
Wataru Mashiko ◽  
Hanako Y. Inoue ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Structure ◽  
Pressure Measurements ◽  
Two Dimensional ◽  
Near Surface

GEOMAGNETIC EFFECTS OF SLOPING AND SHELVING DISCONTINUITIES OF EARTH CONDUCTIVITY

Geophysics ◽  
1971 ◽  
Vol 36 (1) ◽  
pp. 58-66 ◽  
Author(s):  
F. Walter Jones ◽  
Albert T. Price
Keyword(s):  
Apparent Resistivity ◽  
Surface Effects ◽  
Two Dimensional ◽  
Horizontal Extent ◽  
Earth Conductivity ◽  
Conductivity Models

The surface effects on electric and magnetic variations arising from interfaces in three two‐dimensional conductivity models are compared in detail for four frequencies. It is found that the horizontal extent of the surface effects greatly depends on the dimensions of the different structures relative to the skin depths at the frequencies used. Also, a fundamentally important difference is revealed between H‐polarization and E‐polarization problems in that the apparent resistivity computed on the surface near the contact is discontinuous and changes abruptly in the H‐polarization case, whereas for E‐polarization the apparent resistivity is continuous and changes gradually across the contact.

scholarly journals A Fast Two-Dimensional Numerical Method for the Wake Simulation of a Vertical Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
Zheng Yuan ◽  
Jin Jiang ◽  
Jun Zang ◽  
Qihu Sheng ◽  
Ke Sun ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Numerical Method ◽  
Three Dimensional ◽  
Particle Method ◽  
Vortex Method ◽  
Vertical Axis ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Wake Effect ◽  
Array Design

In the array design of the vertical axis wind turbines (VAWT), the wake effect of the upstream VAWT on the downstream VAWT needs to be considered. In order to simulate the velocity distribution of a VAWT wake rapidly, a new two-dimensional numerical method is proposed, which can make the array design easier and faster. In this new approach, the finite vortex method and vortex particle method are combined to simulate the generation and evolution of the vortex, respectively, the fast multipole method (FMM) is used to accelerate the calculation. Based on a characteristic of the VAWT wake, that is, the velocity distribution can be fitted into a power-law function, a new correction model is introduced to correct the three-dimensional effect of the VAWT wake. Finally, the simulation results can be approximated to the published experimental results in the first-order. As a new numerical method to simulate the complex VAWT wake, this paper proves the feasibility of the method and makes a preliminary validation. This method is not used to simulate the complex three-dimensional turbulent evolution but to simulate the velocity distribution quickly and relatively accurately, which meets the requirement for rapid simulation in the preliminary array design.

A Difference Method for Plane Problems in Magnetoelastodynamics

1972 ◽  
Vol 39 (3) ◽  
pp. 689-695 ◽  
Author(s):  
W. W. Recker
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Numerical Method ◽  
Difference Method ◽  
Necessary Condition ◽  
Two Dimensional ◽  
Symmetric Hyperbolic System ◽  
Von Neumann ◽  
First Order ◽  
Independent Variables

The two-dimensional equations of magnetoelastodynamics are considered as a symmetric hyperbolic system of linear first-order partial-differential equations in three independent variables. The characteristic properties of the system are determined and a numerical method for obtaining the solution to mixed initial and boundary-value problems in plane magnetoelastodynamics is presented. Results on the von Neumann necessary condition are presented. Application of the method to a problem which has a known solution provides further numerical evidence of the convergence and stability of the method.

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