fdm module

Module Finite Difference Method describe derivatives used in numerical method (FDM)

Note

The file contains a set of procedures allowing calculations using the finite difference method in cylindrical space (2D) temperature change at any point in time. The procedures were derived for an asymmetric mesh.

t[n] - temperature in node n, d[n] - distance in the coordinates Z and R, between node 4 and node n,
a(k) - temperature equalization factor [m^2/s] for material k

            t[0]                         Z ^
             O                             |
             |     (0)                     |
       (3)   |d[0]                         |
             |                             0----------> R
t[3] O------t[4]-----------O t[1]
       d[3]  |        d[1]
             |     (1)
       (2)   | d[2]
             |
             O
            t[2]
fdm.d2tdr2(t, dx, a)[source]

Second derivative of temperature by radius

Parameters:
  • t – temperature vector [°C]

  • dx – distance from the central node [m]

  • a – temperature equalization factor vector [m^2/s]

Returns:

second derivative of temperature by radius

fdm.d2tdz2(t, dx, a, r)[source]

Second derivative of temperature by depth

Parameters:
  • t – temperature vector [°C]

  • dx – distance from the central node [m]

  • a – temperature equalization factor vector [m^2/s]

  • r – radius counted from the axis of symmetry [m]

Returns:

Second derivative of temperature by depth

fdm.dtdr(t, dx, a, r)[source]

First derivative of temperature by radius

Parameters:
  • t – temperature vector [°C]

  • dx – distance from the central node [m]

  • a – temperature equalization factor vector [m^2/s]

  • r – radius counted from the axis of symmetry [m]

Returns:

first derivative of temperature by radius

fdm.dtdtime(t, dx, a, r)[source]

Derivative of temperature by time

Parameters:
  • t – temperature vector [°C]

  • dx – distance from the central node [m]

  • a – temperature equalization factor vector [m^2/s]

  • r – radius counted from the axis of symmetry [m]

Returns:

Derivative of temperature by time