TECHNICAL FIELD

The present disclosure relates generally to fire suppression systems for a gas turbine engine, and more specifically to a modulated fire extinguishing vent within the same.

BACKGROUND

Gas turbine engines, such as those utilized in commercial and military aircraft, include a compressor section that compresses air, a combustor section in which the compressed air is mixed with a fuel and ignited, and a turbine section across which the resultant combustion products are expanded. The expansion of the combustion products drives the turbine section to rotate. As the turbine section is connected to the compressor section via a shaft, the rotation of the turbine section further drives the compressor section to rotate. In some examples, a fan is also connected to the shaft and is driven to rotate via rotation of the turbine as well.

Due to the potential for onboard fires, gas turbine engines include fire suppression systems. One exemplary fire suppression system included in some engines uses a gaseous fire suppressant to flood a compartment when a fire is detected. The fire suppressant is non-flammable gas, such as a noble gas. Increasing the amount of non-flammable suppressant in the compartment, decreases the concentration of oxygen within the compartment. By reducing the percentage of oxygen in the environment to prevent flammable fluid vapors igniting, the fire is extinguished.

SUMMARY OF THE INVENTION

In one exemplary embodiment a gas turbine engine includes an engine core including a compressor, a combustor fluidly connected to the compressor, and a turbine fluidly connected to the combustor, the engine core defining an axis, a core nacelle disposed radially outward of the engine core, a cavity disposed between an inner surface of the core nacelle and an outer surface of the engine core, the cavity including a vent disposed at an aft end, wherein the vent includes at least one flap configured to be maintained in an unrestricted positon and in a restricted position, and an actuator configured to control the position of the at least one flap.

In another example of the above described gas turbine engine the flap is a normally unrestricted flap.

Another example of any of the above described gas turbine engines further includes a controller configured to apply power to the actuator in response to a fire suppression action.

In another example of any of the above described gas turbine engines the flap is a normally restricted flap.

Another example of any of the above described gas turbine engines further includes a controller configured to mechanically disconnect the actuator from a power supply to the at least one flap in response to a fire suppression action.

Another example of any of the above described gas turbine engines further includes a controller configured to remove power from the actuator in response to a fire suppression action.

In another example of any of the above described gas turbine engines the flap is pivoted radially inward in the restricted position, relative to the unrestricted position.

In another example of any of the above described gas turbine engines the flap is pivoted radially outward in the restricted position, relative to the unrestricted position.

In another example of any of the above described gas turbine engines the flap is extended axially in the restricted position, relative to the unrestricted position.

In another example of any of the above described gas turbine engines the cavity includes a fore inlet configured to receive air from a fan stream, and defines a flowpath from the fore inlet to the vent.

In another example of any of the above described gas turbine engines the at least one flap is a plurality of flaps distributed circumferentially intermittent about the vent.

An exemplary method for suppressing an engine fire in a gas turbine engine includes initiating a fire suppression action by releasing a fire suppressant into a gas turbine engine core cavity and restricting an aft vent of the gas turbine engine core cavity.

In another example of the above described exemplary method for suppressing an engine fire in a gas turbine engine restricting the aft vent of the gas turbine engine comprises allowing the at least one flap to enter a normally restricted position by removing power from an actuator connected to the at least one flap.

In another example of any of the above described exemplary methods for suppressing an engine fire in a gas turbine engine restricting the aft vent of the gas turbine engine comprises allowing the at least one flap to enter a normally restricted position by mechanically disconnecting an actuator from the at least one flap.

In another example of any of the above described exemplary methods for suppressing an engine fire in a gas turbine engine restricting the aft vent of the gas turbine engine comprises causing the at least one flap to enter a restricted position from a normally unrestricted position by applying power to an actuator connected to the at least one flap.

In another example of any of the above described exemplary methods for suppressing an engine fire in a gas turbine engine restricting the at least one flap restricts airflow out of the core cavity, thereby decreasing a volume of fire suppressant required to lower a concentration of oxygen in the engine core cavity below an auto ignition level.

In one exemplary embodiment a gas turbine engine includes an engine core defining an axis and including a static structure surrounding a compressor, a combustor, and a turbine, the static structure at least partially defining a core cavity including a fore inlet configured to intercept airflow from a fan stream and including an aft vent configured to vent gas from the core cavity, the engine core defining an axis, wherein the vent includes at least one flap configured to be maintained in an unrestricted positon and in a restricted position via an actuator, and a controller configured to cause the at least one flap to transition to the restricted position in response to a fire suppression instruction.

In another example of the above described gas turbine engine the at least one flap is a normally restricted flap.

In another example of any of the above described gas turbine engines the at least one flap is a normally unrestricted flap.

In another example of any of the above described gas turbine engines the at least one flap is a plurality of flaps disposed circumferentially about the vent.

These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

