Untitled0.rst

# Rayleigh formula for free thermal convection, formulae taken from Kuhn and Gessner 2009, Surveys in Geophysics

def Rayleigh():
    """ Properties of pure water at 20 degrees K """
    # values of pure water taken from http://people.ucsc.edu/~bkdaniel/WaterProperties.html
    alpha =((0.207 + 0.385 + 0.523) / 3) * 1*10**-3 # thermal expansivity of water
    print alpha
    rho = 998.0 # Density of pure water
    c = 4179.0 # Fluid heat capacity
    g = 9.812
    mu = ((1.004 + 0.658 + 0.475) / 3) * 1*10**-3 #dynamic viscosity of water
    """ Mean Values """
    WLFM0_xyz = 2.7, #np.array(S1_out.get_array_as_xyz_structure("WLFM0"))
    WLFM0_mean = 2.7 #np.mean(WLFM0_xyz[:, :, :]) # Mean of medium's thermal expansivity
    #print WLFM0_mean

    perm_xyz = 1E-12 # np.array(S1_out.get_array_as_xyz_structure("PERM"))
    mean_perm = 1E-12 # np.mean(perm_xyz[:,:,:]) # Mean of permeability field
    #mean_perm = 5.835e-12
    #print "%0.4g" %mean_perm

   #temp_xyz = np.array(S1_out.get_array_as_xyz_structure("TEMP")) # determine temperature gradient at the subplot
    T2 = 170. #temp_xyz[0:, :, 0]
    T1 = 20. # temp_xyz[0:, :, -1]
    # z_axis = temp_xyz[0, :, 0:]
    # z_axis_list = list(z_axis[:,:].ravel(order = "F"))
    length = 1000. # len(z_axis_list) * 100.0
    #print length
    Value = (T2 - T1) / length
    dtemp_value = Value # np.mean(Value[:, :])

    print dtemp_value

    Ra = ((T2 - T1) * mean_perm * length * alpha * (rho**2) * g * c) / (WLFM0_mean * mu)
    return Ra
print "%0.4g" %Rayleigh()

0.000371666666667
0.15
1184