Adjusts the scaling factor calculation - scaling of rubber engines - to use...

Adjusts the scaling factor calculation - scaling of rubber engines - to use deck values instead of the engine xml.

The deltas are small. For the V2527 the scale factor increases about 1 percent. For the PW it is almost the same. However, the process is more reasonable because the decks will be used in the furhter design process.

Several TODOs are also managed by this as we questioned the robustness and the validity of the approach.

propulsion_design/src/engine_design/rubber/turbofan.cpp

@@ -55,12 +55,22 @@ namespace design
                                 {this->engine_directory(), this->engine_database()});
 
         /* Scale the engine */
-        /** @todo How and which thrust do we need here? */
+
+        /* Load the unscaled engine */
+        auto engine_unscaled = io::load_engine_scaled(
+            engine.model(),
+            1,
+            {this->engine_directory(),
+             this->engine_database()});
+
+        /* Get the unscaled SLST value from the deck values as the highest N1 at SLS */
+        engine_unscaled.calculate_N1_with_penalties(0 , 0, this->flight_condition().ambiance, 1.0, "takeoff", 0, 0);
+
+        /* Scale the engine */
         engine.set_scale(
-            engine.required_thrust() > 0.0 ? engine.required_thrust() / engine_data.SLST() : 1.0);
+            engine.required_thrust() > 0.0 ? engine.required_thrust() / engine_unscaled.get_thrust() : 1.0); // engine_unscaled.get_thrust()
 
-        /* Set and sale the parameters */
-        /** @todo Where does the scaling of the length come from ?*/
+        /* Set and sale the parameters according to Ray12 p. 285 */
         engine.set_dimension({engine_data.dimensions().height * std::pow(engine.scale(), 0.5),
                               engine_data.dimensions().width * std::pow(engine.scale(), 0.5),
                               engine_data.dimensions().length * std::pow(engine.scale(), 0.4)});