#include <Main/fg_props.hxx>
-VacuumSystem::VacuumSystem ()
+VacuumSystem::VacuumSystem( int i )
{
+ num = i;
}
VacuumSystem::~VacuumSystem ()
}
void
-VacuumSystem::init ()
+VacuumSystem::init()
{
- // TODO: allow index of pump and engine
- // to be configured.
- _serviceable_node = fgGetNode("/systems/vacuum[0]/serviceable", true);
+ // TODO: allow index of engine to be
+ // configured.
+ SGPropertyNode *node = fgGetNode("/systems/vacuum", num, true );
+ _serviceable_node = node->getChild("serviceable", 0, true);
_rpm_node = fgGetNode("/engines/engine[0]/rpm", true);
_pressure_node = fgGetNode("/environment/pressure-inhg", true);
- _suction_node = fgGetNode("/systems/vacuum[0]/suction-inhg", true);
+ _suction_node = node->getChild("suction-inhg", 0, true);
}
void
} else {
double rpm = _rpm_node->getDoubleValue();
double pressure = _pressure_node->getDoubleValue();
- suction = pressure * rpm / (rpm + 10000.0);
- if (suction > 5.0)
- suction = 5.0;
+ // This magic formula yields about 4 inhg at 700 rpm
+ suction = pressure * rpm / (rpm + 4875.0);
+
+ // simple regulator model that clamps smoothly to about 5 inhg
+ // over a normal rpm range
+ double max = 5.39 - 1.0 / ( rpm * 0.00111 );
+ if ( suction < 0.0 ) suction = 0.0;
+ if ( suction > max ) suction = max;
}
_suction_node->setDoubleValue(suction);
}