Add speed curve component

Author: peternewell

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

@@ -2009,7 +2009,7 @@ public virtual void UpdateCurveForce(float elapsedClockSeconds)
             if (CurrentCurveRadius > 0)
             {
                 if (RigidWheelBaseM == 0)   // Calculate default values if no value in Wag File
-                {                        
+                {
                     float Axles = WheelAxles.Count;
                     float Bogies = Parts.Count - 1;
                     float BogieSize = Axles / Bogies;
@@ -2074,34 +2074,41 @@ public virtual void UpdateCurveForce(float elapsedClockSeconds)
                             //    Approximation for calculating rigid wheelbase for steam locomotives
                             // Wheelbase = 1.25 x (Loco Drive Axles - 1.0) x Drive Wheel diameter
 
-                            RigidWheelBaseM = 1.25f * (LocoNumDrvAxles - 1.0f) * (DriverWheelRadiusM * 2.0f); 
+                            RigidWheelBaseM = 1.25f * (LocoNumDrvAxles - 1.0f) * (DriverWheelRadiusM * 2.0f);
                         }
                     }
                 }
 
                 // References:
 
-               // i) The modern locomotive by  Clarence Edgar Allen – 1912 – pg 82 - https://archive.org/details/modernlocomotive00allerich
+                // i) The modern locomotive by  Clarence Edgar Allen – 1912 – pg 82 - https://archive.org/details/modernlocomotive00allerich
 
-               //  ii)	Resistance to Traffic of Railway Rolling Stock by P.N.Astakhov – Moscow 1966 – pg 112
-               //  http://scbist.com/scb/uploaded/1_astahov_p_n_soprotivlenie_dvizheniyu_zheleznodorozhnogo_podv.pdf
+                //  ii)	Resistance to Traffic of Railway Rolling Stock by P.N.Astakhov – Moscow 1966 – pg 112
+                //  http://scbist.com/scb/uploaded/1_astahov_p_n_soprotivlenie_dvizheniyu_zheleznodorozhnogo_podv.pdf
 
-                // The CurveForce is a combination of these two components so that resistance will vary with stock characteristics and speed.
+                // The CurveForce is a combination of these two components such that resistance will vary with stock characteristics and speed.
                 // These formulas are a mix of imperial and metric expressions so these will be retained and converted to a common UoM in Newtons once calculations are complete.
 
                 // Base Curve Resistance (from refernce i)) = (Vehicle mass x Coeff Friction) * (Track Gauge + Vehicle Fixed Wheelbase) / (2 * curve radius)
                 // Vehicle Fixed Wheel base is the distance between the wheels, ie bogie or fixed wheels
 
-                CurveForceN = N.FromLbf(Kg.ToLb(MassKG) * Train.WagonCoefficientFriction * (Me.ToFt(TrackGaugeM) + Me.ToFt(RigidWheelBaseM)) / (2.0f * Me.ToFt(CurrentCurveRadius)));
+                var rBaseWagonN = N.FromLbf(Kg.ToLb(MassKG) * Train.WagonCoefficientFriction * (Me.ToFt(TrackGaugeM) + Me.ToFt(RigidWheelBaseM)) / (2.0f * Me.ToFt(CurrentCurveRadius)));
+
+                //                if (CurrentCurveRadius > 0)
+                //                    Trace.TraceInformation("Curve Friction - CarID {0}  Friction {1} Weight {2} WagonFriction {3} Gauge {4} WheelBase {5} CurveRadius {6}", CarID, rBaseWagonN, Kg.ToLb(MassKG), Train.WagonCoefficientFriction, Me.ToFt(TrackGaugeM), Me.ToFt(RigidWheelBaseM), Me.ToFt(CurrentCurveRadius));
+
+                // Speed Curve Resistance (from reference ii) - second term only) = ((Speed^2 / Curve Radius) - (Superelevation / Track Gauge) * Gravitational acceleration) * Constant
+
+                var speedConstant = 1.5f;
+                var MToMM = 1000;
+                var rspeedKgpTonne = speedConstant * Math.Abs((SpeedMpS * SpeedMpS / CurrentCurveRadius) - ((MToMM * SuperelevationM / MToMM * TrackGaugeM) * GravitationalAccelerationMpS2));
+                var rSpeedWagonN = GravitationalAccelerationMpS2 * (Kg.ToTonne(MassKG) * rspeedKgpTonne);
 
-                var tempCurveFriction = Kg.ToLb(MassKG) * Train.WagonCoefficientFriction * (Me.ToFt(TrackGaugeM) + Me.ToFt(RigidWheelBaseM)) / (2.0f * Me.ToFt(CurrentCurveRadius));
+//                if (CurrentCurveRadius > 0)
+//                    Trace.TraceInformation("Curve Friction Speed - CarID {0}  Weight {1} WagonFriction {2} Gauge {3} CurveRadius {4} SuperElevation {5} Gauge {6} rspeedKgpTonne {7} rSpeedWagonN {8} rBaseWagonN {9}", CarID, Kg.ToTonne(MassKG), Train.WagonCoefficientFriction, TrackGaugeM, CurrentCurveRadius, SuperelevationM, TrackGaugeM, rspeedKgpTonne, rSpeedWagonN, rBaseWagonN);
 
- //               if (CurrentCurveRadius > 0)
- //                   Trace.TraceInformation("Curve Friction - CarID {0}  Friction {1} Weight {2} WagonFriction {3} Gauge {4} WheelBase {5} CurveRadius {6}", CarID, tempCurveFriction, Kg.ToLb(MassKG), Train.WagonCoefficientFriction, Me.ToFt(TrackGaugeM), Me.ToFt(RigidWheelBaseM), Me.ToFt(CurrentCurveRadius));
 
-               // float CurveResistanceSpeedFactor = Math.Abs((MaxCurveEqualLoadSpeedMps - AbsSpeedMpS) / MaxCurveEqualLoadSpeedMps) * StartCurveResistanceFactor;
-               //  CurveForceN *= CurveResistanceSpeedFactor * CurveResistanceZeroSpeedFactor;
-              //   CurveForceN *= GravitationalAccelerationMpS2; // to convert to Newtons
+                CurveForceN = rBaseWagonN + rSpeedWagonN;
             }
             else
             {