Controlled equilibrium mounts for aircraft engine isolation

Softer than usual engine mounts for aircraft engine isolation can be used by adding control of the equilibrium position of the mount. The control power comes from bypass air from the engine. This isolation concept is called a controlled equilibrium mount or CEM. A model of the CEM has been developed which includes a front and rear mount with proper loading for each. These mounts possess passive stiffness and damping properties, and they can be pressurized or exhausted through control valves. The thermodynamics of the air is also modeled. A control strategy is proposed that keeps the mounts at their equilibrium positions. The simulation results show that the supply pressure and temperature of the bypass air varied with flight conditions. However, the variations are acceptable, and equilibrium can be maintained with acceptable flow rates from the bypass air for most flight conditions.