Merge branch 'fix/tank_design_liquid_hydrogen' into 'main'

Fix tank design LH2

See merge request !253

tank_design/src/tube_and_wing/empirical/tank_design_tu_berlin/liquid_hydrogen/methodliquidhydrogen.py

@@ -53,9 +53,12 @@ def method_liquid_hydrogen(paths_and_names, routing_dict, dict_ac_exchange, dict
 
     """ Preparation. """
     # Check if any values from aircraft exchange file are missing.
+    # Since no tank information is available in the first loop, these values are excluded from the check.
+    values_to_exclude = ['tank_designator', 'tank_cross_section_name', 'tank_cross_section_position',
+                         'additional_fuselage_length']
     for key, value in dict_ac_exchange.items():
         # Check, if any value is 'None'.
-        if value is None:
+        if (key not in values_to_exclude) and (value is None):
             # If any value is 'None', the tank design is impossible and the program aborted.
             runtime_output.critical('Error: Tank design not possible due to missing parameter in aircraft exchange '
                                     + 'file (' + key + ')! '