Some materials have invalid heat capacity values

[PGorzalka]

What is the problem?

• Some materials in teaser/data/input/inputdata/MaterialTemplates.json have "heat_capac": 0.0.

Why do we want to solve it?

• This causes nan values for all the relevant parameters r1, r2, r3, c1, c2 in teaser.logic.buildingobjects.buildingphysics.wall.calc_equivalent_res()

How do we want to solve it?

• Plausible heat capacity values should be added for those materials, e.g. derived from literature values. As the required unit is kJ / kg K and should mostly be around 1 anyway, adding 1.0 for all of them is a possible hotfix.

[PGorzalka]

reproduce this with the following code, which is the function mentioned above without the self.

import numpy as np

area = 2
nr_of_layer = 2
density = np.array([500, 500])
thermal_conduc = np.array([0.162, 0.7])
heat_capac = np.array([0.0, 1.17])
thickness = np.array([0.2, 0.2])

t_bt = 7
omega = 2 * np.pi / (86400 * t_bt)
r_layer = thickness / thermal_conduc
c_layer = heat_capac * density * thickness * 1000
re11 = np.cosh(np.sqrt(0.5 * omega * r_layer * c_layer)) * \
       np.cos(np.sqrt(0.5 * omega * r_layer * c_layer))
im11 = np.sinh(np.sqrt(0.5 * omega * r_layer * c_layer)) * \
       np.sin(np.sqrt(0.5 * omega * r_layer * c_layer))
re12 = r_layer * np.sqrt(1 / (2 * omega * r_layer * c_layer)) * \
       (np.cosh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.sin(np.sqrt(0.5 * omega * r_layer * c_layer)) +
        np.sinh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.cos(np.sqrt(0.5 * omega * r_layer * c_layer)))
im12 = r_layer * np.sqrt(1 / (2 * omega * r_layer * c_layer)) * \
       (np.cosh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.sin(np.sqrt(0.5 * omega * r_layer * c_layer)) -
        np.sinh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.cos(np.sqrt(0.5 * omega * r_layer * c_layer)))
re21 = (-1 / r_layer) * (np.sqrt(0.5 * omega * r_layer * c_layer)) * \
       (np.cosh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.sin(np.sqrt(0.5 * omega * r_layer * c_layer)) -
        np.sinh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.cos(np.sqrt(0.5 * omega * r_layer * c_layer)))
im21 = (1 / r_layer) * (np.sqrt(0.5 * omega * r_layer * c_layer)) * \
       (np.cosh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.sin(np.sqrt(0.5 * omega * r_layer * c_layer)) +
        np.sinh(np.sqrt(0.5 * omega * r_layer * c_layer)) *
        np.cos(np.sqrt(0.5 * omega * r_layer * c_layer)))
re22 = re11
im22 = im11
# -----setting up the matrix for each layer
a_layer = np.zeros((nr_of_layer, 4, 4))
for i, r in enumerate(re11):
    a_layer[i][0][0] = r
    a_layer[i][0][1] = im11[i]
    a_layer[i][0][2] = re12[i]
    a_layer[i][0][3] = im12[i]
    a_layer[i][1][0] = -im11[i]
    a_layer[i][1][1] = re11[i]
    a_layer[i][1][2] = -im12[i]
    a_layer[i][1][3] = re12[i]
    a_layer[i][2][0] = re21[i]
    a_layer[i][2][1] = im21[i]
    a_layer[i][2][2] = re22[i]
    a_layer[i][2][3] = im22[i]
    a_layer[i][3][0] = -im21[i]
    a_layer[i][3][1] = re21[i]
    a_layer[i][3][2] = -im22[i]
    a_layer[i][3][3] = re22[i]
# -----multiplication of the matrix
new_mat = np.diag(np.ones(4))
for count_layer in a_layer:
    new_mat = np.dot(new_mat, count_layer)

# calculation of equivalent Resistance and capacities of each element
r1 = (1 / area) * ((new_mat[3][3] - 1) *
                   new_mat[0][2] + new_mat[2][3] *
                   new_mat[0][3]) / \
     ((new_mat[3][3] - 1) ** 2 + new_mat[2][3] ** 2)
r2 = (1 / area) * ((new_mat[0][0] - 1) *
                   new_mat[0][2] + new_mat[0][1] *
                   new_mat[0][3]) / \
     ((new_mat[0][0] - 1) ** 2 + new_mat[0][1] ** 2)
c1 = area * ((new_mat[3][3] - 1) ** 2 +
             (new_mat[2][3]) ** 2) / \
     (omega * (new_mat[0][2] * new_mat[2][3] -
               (new_mat[3][3] - 1) * new_mat[0][3]))
c2 = area * ((new_mat[0][0] - 1) ** 2 +
             (new_mat[0][1]) ** 2) / (
             omega * (new_mat[0][2] *
                      new_mat[0][1] -
                      (new_mat[0][0] - 1) *
                      new_mat[0][3]))
r3 = (1 / area) * (np.sum(r_layer)) - r1 - r2
r_wall = r1 + r2 + r3
c1_korr = (1 / (omega * r1)) * ((r_wall * area -
                                 new_mat[0][2] * new_mat[3][
                                     3] -
                                 new_mat[0][3] * new_mat[2][
                                     3]) /
                                (new_mat[3][3] * new_mat[0][
                                    3] -
                                 new_mat[0][2] * new_mat[2][
                                     3]))