Tobias Weckenmann
--- a/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+++ b/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+    - data related outputs (e.g. engine position)
+- the configuration file `propulsion_design_conf.xml` (also _configXML_) includes
+    - control settings (e.g. enable/disable generating plots)
+    - program settings (e.g. set technology factors or methods)
+
+### Aircraft exchange file
+@note _acXML_ is an exchange file - we agreed on that only data will be saved as output which is needed by another tool!
+
+**Inputs**: 
+Following is needed from the _acXML_:
+1) the total thrust-to-weight-ratio as well as the MTOM, 
+2) the thrust share of the individual engine,
+2) the average system off-takes of the engines,
+3) the user settings of the propulsion architecture.
+
+Naturally, the propulsion need an assumption for thrust or power to be designed. In the first iteration in UNICADO, the requirement is set via the tool _initialSizing_. It is then updated in _constraint_analysis_ in every loop to assure that the thrust that is fitted onto the aircraft assures enough thrust in all required flight stages. For this, **propulsion_design** currently assumes:
--- a/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+++ b/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+Naturally, the propulsion need an assumption for thrust or power to be designed. In the first iteration in UNICADO, the requirement is set via the tool _initialSizing_. It is then updated in _constraint_analysis_ in every loop to assure that the thrust that is fitted onto the aircraft assures enough thrust in all required flight stages. For this, **propulsion_design** currently assumes:
+
+The sea level static thrust \f$ T_0 \f$ is given by:
+
+\f$
+T_0 = \frac{T}{W} \cdot MTOM
+\f$
+
+Where:
+- \f$ T_0 \f$ is the sea level static thrust.
+- \f$ \frac{T}{W} \f$  is the thrust-to-weight ratio (specified as `/aircraft_exchange_file/sizing_point/thrust_to_weight`).
+- \f$ MTOM \f$ is the maximum takeoff mass (specified as `/aircraft_exchange_file/analysis/masses_cg_inertia/maximum_takeoff_mass`).
+
+@note This might change with new propulsion architectures!
+
+Not only the ratio of thrust to weight is read, but also the average system off-takes. In the current design of UNICADO, engine provide power for the systems and therefore the thrust specific energy/fuel consumption will increase. To include that, the nodes `average_bleed_air_demand` and `average_bleed_air_demand` in `/aircraft_exchange_file/component_design/systems/specific/`are read to show the influence of these offtakes on the bucket curve (is set to default values if not existing).
--- a/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+++ b/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+Energy Carriers
+|- Energy Carrier (ID=0)
+|  |- Type
+Propulsion
+|- Propulsor (ID=0)
+|  |- Powertrain
+|  |- Type
+|  |- Position
+|  |  |- Parent Component
+|  |  |- X
+|  |  |- Y
+|  |  |- Z
+|  |- Energy Carrier ID
+|  |- Thrust Share
+```
+Let's assume you want to design an aircraft with 5 engine - 2 on each side of the wing and one in the empennage. Additionally, you want to use 3 energy carrier: hydrogen, kerosene and battery-electric.
--- a/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+++ b/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+|- Energy Carrier (ID=0)
+|  |- Type
+Propulsion
+|- Propulsor (ID=0)
+|  |- Powertrain
+|  |- Type
+|  |- Position
+|  |  |- Parent Component
+|  |  |- X
+|  |  |- Y
+|  |  |- Z
+|  |- Energy Carrier ID
+|  |- Thrust Share
+```
+Let's assume you want to design an aircraft with 5 engine - 2 on each side of the wing and one in the empennage. Additionally, you want to use 3 energy carrier: hydrogen, kerosene and battery-electric.
+For that, you need to define 3 energy carriers with each a type with \f$ID=[0,1,2]\f$. Then you create 5 propulsor nodes with \f$ID=[0,...,4]\f$ and assign them each an a powertrain, type, ..., and thrust share. E.g. Engine 0 shall be a kerosene-powered turbofan in the empennage with a thrust share of \f$10\%\f$. Then it has the position with `parent_component=empennage`, `x=front`, `y=mid`, `z=in`. If the type of the energy carrier with ID=0 is set to kerosene, you need to assign `energy_carrier_id=0`. Also `powertrain=turbo`, `type=fan`, and `thrust_share=0.1`. Then Engine 1 could be a hydrogen-powered turboprop located under the left front inner wing with a thrust share of \f$25\%\f$. Then it has the position with `parent_component=wing`, `x=front`, `y=left`, `z=under`. If the type of the energy carrier with ID=1 is set to hydrogen, you need to assign `energy_carrier_id=1`. Also `powertrain=turbo`, `type=prop`, and `thrust_share=0.25`. The same procedure needs to be done for the other 3 engine.
--- a/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+++ b/docs/documentation/sizing/propulsion_design/getting_started.md 0 → 100644
+|  |- Nacelle Mass
+|  |- Pylon Mass
+|  |- Engine Efficiency
+|- Propulsion (ID=Default)
+|  |- Engine
+|  |  |- Empirical
+|  |  |  |- BPR
+|  |  |- Rubber
+|  |  |- GasTurb
+|  |- Nacelle
+|  |  |- Profile
+|  |- Pylon
+|  |  |- Profile
+|  |- Integration
+```
+You can choose the method for each discipline, the path for your engine data base, and different technology factors. To be highlighted, is the `Propulsion ID=Default` node. This is a default for all engines defined in the _acXML_ (see next paragraph). E.g. if you define 3 engines for an aircraft, both will use the same assumptions in the default setting. In case you want that the 3. engine is been calculated with e.g. another method, you can create a new `propulsion` node and assign the same `ID` value as set for the _acXML_ `ID`.