Differences

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--- aircraft:tmd:turbo_engines [2021/02/12 13:01] – [Step 6 - Engine control (FADEC)] jh
+++ aircraft:tmd:turbo_engines [2022/08/02 10:00] (current) – jh
@@ Line 27: / Line 27: @@
 <code>            <[input_lever][Throttle1Input][]
-                <[string8][Input][Controls.Throttle1]>
+                <[string8][Message][Controls.Throttle1]>
             >
             <[turbofan][Engine1][]
@@ Line 73: / Line 73: @@
 <code>            // engine controls
             <[input_lever][Throttle1Input][]
-                <[string8][Input][Controls.Throttle1]>
+                <[string8][Message][Controls.Throttle1]>
             >
             <[constant][Reverser1Flaps][]
@@ Line 451: / Line 451: @@
 Turbo-engines in real life are often controlled by full authority digital engine controllers (FADECs). These take sensor readings from the engine, air data computers, thrust lever angle and other inputs to compute the required engine fuel flow.
-For a very basic fuel controller you can implement a fuel flow proportional to the compressor output pressure.
+For a very basic fuel controller you can implement a fuel flow proportional to the compressor output pressure and add a governor proportional to the speed deviation. Do something similar like this in the tmd:
-Do something like this in the tmd:
 <code>Governor = C_Gov * ( TargetN1 - N1 )
@@ Line 459: / Line 457: @@
 Enrichment = Engine1Station3.OutputTotalPressure / ( PitotTube.StaticPressure * DesignCompressionRatio ).
-FuelFlowRaw = C_FF * ( Governor + Enrichment )
+Gain = PitotTube.StaticPressure / 101325.0
+FuelFlowRaw = Gain * C_FF * ( Governor + Enrichment )
 FuelFlow = clamp( FuelFlowRaw, MinFuelFlow, MaxFuelFlow )</code>
+where C_Gov is your governor gain (about 0.2 is ok), and C_FF is your fuel flow constant, use your maximum takeoff fuel flow at the beginning. MinFuelFlow is your idle fuel flow at high altitude (high enough to prevent flame out) and MaxFuelFlow is your takeoff fuel flow plus a small amount. DesignCompressionRatio is the compression ratio that you see at takeoff power (depending on the engine data, ranges between like 11 to 42).