Updated to latest JSBSim, including preliminary support for

windmilling propellers.

diff --git a/src/FDM/JSBSim/FGPropeller.cpp b/src/FDM/JSBSim/FGPropeller.cpp
index 5804117fce13ea9f88f7c1378675ad0b62ee47b6..bd0567c0a9e4a24ee76106bae121c00ded0040e3 100644 (file)
--- a/src/FDM/JSBSim/FGPropeller.cpp
+++ b/src/FDM/JSBSim/FGPropeller.cpp
@@ -154,9 +154,18 @@ double FGPropeller::Calculate(double PowerAvailable)
   }
 
   Thrust = C_Thrust*RPS*RPS*Diameter*Diameter*Diameter*Diameter*rho;
-  vFn(1) = Thrust;
   omega = RPS*2.0*M_PI;
 
+  // Check for windmilling.
+  double radius = Diameter * 0.375; // 75% of radius
+  double windmill_cutoff = tan(Pitch * 1.745329E-2) * omega * radius;
+  if (Vel > windmill_cutoff) {
+    cout << "Windmilling: " << Vel << " > " << windmill_cutoff << endl;
+    Thrust = -Thrust;
+  }
+
+  vFn(1) = Thrust;
+
   // The Ixx value and rotation speed given below are for rotation about the
   // natural axis of the engine. The transform takes place in the base class
   // FGForce::GetBodyForces() function.
@@ -187,6 +196,7 @@ double FGPropeller::GetPowerRequired(void)
   double rho = fdmex->GetAtmosphere()->GetDensity();
 
   if (MaxPitch == MinPitch) { // Fixed pitch prop
+    Pitch = MinPitch;
     cPReq = cPower->GetValue(J);
   } else {                    // Variable pitch prop
     double advance = fdmex->GetFCS()->GetPropAdvance(ThrusterNumber);