In this paper, PSSE is considered in the rectangular and polar coordinate systems. Up to now, such the investigations have not been considered in existing papers.
In this situation, there were carried out: (i) original calculations of the considered indices for representative operational states of the test PS when SE is performed in the rectangular and polar coordinate systems and in PS there is and there is no PhS, (ii) original statistical analyses of the calculated indices, (iii) original discussion on the causes of observed regularities.
As is shown in Figure 11, vorticity is calculated by the adjacent meshes in Doppler velocity data in the polar coordinate system. It should be noted that our focus was to analyze vortex behavior in three-dimensions, so both positive and negative vorticity were important for analysis.
For each event, the count of vorticity is calculated using the processed data in the polar coordinate system. By summarizing the count and absolute value of vorticity in all baby-rain-cells, Figure 13 shows the frequency distribution of absolute value of vorticity in the first echo of all collected events.
(6) Draw: in the polar coordinate system, it is appropriate to use the equivalent permeability coefficients of 36 directions in Step (5) to draw the diagram, to see whether it can form an ellipse, so we know whether the REV is existent or not.
Solve (7), where the ellipse equation of the permeability coefficient in the polar coordinate system is
The number of evaluation points in
polar coordinate system is determined by distances between evaluation points and wheel loads in the Cartesian coordinate system as shown in Fig.
In the first phase, we convert the conventional Cartesian coordinate system to a
polar coordinate system, as depicted in Fig.
The model based on the finite-difference method in
polar coordinate system for corona field computation is suitable to use in usual personal computers.
An expression of Poisson's equation in
polar coordinate system is the sum of second partial derivatives in respect of coordinates r and [phi]: