Use tractive force in diesel engines

Author: cesarBLG

Source/Orts.Simulation/Simulation/RollingStocks/MSTSLocomotive.cs

@@ -2263,7 +2263,7 @@ public override void Update(float elapsedClockSeconds)
             UpdateHornAndBell(elapsedClockSeconds);
 
             UpdateSoundVariables(elapsedClockSeconds);
-            PrevMotiveForceN = MotiveForceN;
+            PrevTractiveForceN = MotiveForceN;
             base.Update(elapsedClockSeconds);
 
 #if DEBUG_ADHESION

Source/Orts.Simulation/Simulation/RollingStocks/MSTSSteamLocomotive.cs

@@ -6284,10 +6284,7 @@ protected override void UpdateTractiveForce(float elapsedClockSeconds, float loc
                 {
                     absStartTractiveEffortN = Math.Abs(TractiveForceN); // update to new maximum TE
                 }
-            }          
-
-            MotiveForceSmoothN.Update(elapsedClockSeconds, MotiveForceN);
-            MotiveForceSmoothedN = MotiveForceSmoothN.SmoothedValue;
+            }
             if (float.IsNaN(MotiveForceN))
                 MotiveForceN = 0;
 

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/PowerSupplies/DieselEngine.cs

@@ -1039,12 +1039,12 @@ public void Update(float elapsedClockSeconds)
             DemandedThrottlePercent = Math.Max(DemandedThrottlePercent, ReverseThrottleRPMTab[Locomotive.DieselPowerSupply.DieselEngineMinRpm]);
 
             if (Locomotive.Direction == Direction.Reverse)
-                Locomotive.PrevMotiveForceN *= -1f;
+                Locomotive.PrevTractiveForceN *= -1f;
 
             if ((State == DieselEngineState.Running) && (Locomotive.ThrottlePercent > 0))
             {
-                var abstempMotiveForce = Math.Abs(Locomotive.PrevMotiveForceN);
-                OutputPowerW = ( abstempMotiveForce > 0 ? abstempMotiveForce * Locomotive.AbsSpeedMpS : 0) / Locomotive.DieselEngines.NumOfActiveEngines;
+                var abstempTractiveForce = Math.Abs(Locomotive.PrevTractiveForceN);
+                OutputPowerW = ( abstempTractiveForce > 0 ? abstempTractiveForce * Locomotive.AbsSpeedMpS : 0) / Locomotive.DieselEngines.NumOfActiveEngines;
             }
             else
             {

Source/Orts.Simulation/Simulation/RollingStocks/TrainCar.cs

@@ -548,11 +548,16 @@ public Direction Direction
         public float PreviousSteamBrakeCylinderPressurePSI;
 
         // TrainCar.Update() must set these variables
-        public float MotiveForceN;   // ie motor power in Newtons  - signed relative to direction of car -
-        public float TractiveForceN = 0f; // Raw tractive force for electric sound variable2
-        public SmoothedData MotiveForceSmoothN = new SmoothedData(0.5f);
-        public float MotiveForceSmoothedN;
-        public float PrevMotiveForceN;
+        /// <summary>
+        /// Force transmitted to rail, excluding brake force
+        /// Adhesion-corrected tractive force
+        /// </summary>
+        public float MotiveForceN;
+        /// <summary>
+        /// Tractive force generated by the engine(s)
+        /// </summary>
+        public float TractiveForceN = 0f;
+        public float PrevTractiveForceN;
         // Gravity forces have negative values on rising grade. 
         // This means they have the same sense as the motive forces and will push the train downhill.
         public float GravityForceN;  // Newtons  - signed relative to direction of car.