def zeroThrustForces(self, flightPitchDegrees, AoADegrees, v, altitude, planet):
"""
Return the forces other than thrust that this part produces.
Returns a tuple (drag, lift, apparentGravity) with quantities in kN.
Lift and drag are vectors; gravity is a number (just the y coordinate, positive means up).
"""
Cd = self._staticCd
Clift = 0
if isinstance(self._parttype, lift.wing):
Cd = self._parttype.dragCoeff(self._AoA + AoADegrees)
Clift = self._parttype.liftCoeff(self._AoA + AoADegrees)
elif isinstance(self._parttype, jets.intake):
Cd = self._parttype.dragCoeff(self._AoA + AoADegrees)
elif isinstance(self._parttype, jets.jetengine):
Cd = 0.2
elif isinstance(self._parttype, engine.engine):
Cd = 0.2
dragMagnitude = planet.dragForce(altitude, v, self.mass(), Cd)
liftMagnitude = v * planet.pressure(altitude) * Clift
flightPitchRad = math.radians(flightPitchDegrees)
cosPitch = math.cos(flightPitchRad)
sinPitch = math.sin(flightPitchRad)
horizontalSpeedSrf = v * cosPitch
horizontalSpeedOrb = horizontalSpeedSrf + planet.siderealSpeed(altitude)
vOrbit = planet.orbitalVelocity(altitude)
centrifuge = horizontalSpeedOrb * horizontalSpeedOrb / (vOrbit * vOrbit)
gravity = planet.gravity(altitude)
downForceMagnitude = self.mass() * (centrifuge - gravity)
dragVector = physics.vector(-cosPitch * dragMagnitude, -sinPitch * dragMagnitude)
liftVector = physics.vector(-sinPitch * liftMagnitude, cosPitch * liftMagnitude)
return (dragVector, liftVector, downForceMagnitude)
def standardDrag(mass):
f = planet.dragForce(altitude, v, mass, 0.2)
return (-f * flightPitchCos, -f * flightPitchSin)
def dragForce(self, AoAdegrees, v, altitude = 0, planet = planet.kerbin):
Cd = self.deflectionDrag(AoAdegrees) * self.drag
return planet.dragForce(altitude, v, self.mass, Cd)
def dragForce(self, AoAdegrees, v, altitude = 0, planet = planet.kerbin):
Cd = self.dragCoeff(AoAdegrees)
return planet.dragForce(altitude, v, self.mass, Cd)
