A system for operating a gas turbine engine to mitigate the risk of ice formation within the engine, the system including a controller arranged to control at least one operational parameter of the engine such that the engine operates in a safe zone; and, a processor configured to function as a determining module to make a comparison between values and determine whether the engine is operating within a safe zone based on at least a core pressure parameter relating to the pressure within the engine and a core temperature parameter relating to the temperature within the engine, wherein the safe zone is defined by the product (multiplied) of the core pressure parameter and core temperature parameter being above a safe threshold.

An anti-icing system of a nacelle inlet of an engine of an aircraft includes first and second direct acting valves and first and second control valve assemblies fluidly connected to the nacelle inlet. The first direct acting valve includes a first inlet, outlet, valve chamber, and piston. The first piston is positioned in the first direct acting valve. The first control valve assembly is fluidly connected to the first valve. The second direct acting valve includes a second inlet, outlet, valve chamber, and piston. The second piston is positioned in the second direct acting valve. The second direct acting valve is fluidly connected to the first direct acting valve in a series configuration. The second control valve assembly is fluidly connected to the second valve chamber.

An anti-icing system of a nacelle inlet of an engine of an aircraft includes first and second direct acting valves and first and second control valve assemblies fluidly connected to the nacelle inlet. The first direct acting valve includes a first inlet, outlet, valve chamber, and piston. The first piston is positioned in the first direct acting valve. The first control valve assembly is fluidly connected to the first valve. The second direct acting valve includes a second inlet, outlet, valve chamber, and piston. The second piston is positioned in the second direct acting valve. The second direct acting valve is fluidly connected to the first direct acting valve in a series configuration. The second control valve assembly is fluidly connected to the second valve chamber.

A gas turbine engine may include a turbomachine defining a core flow having a core mass flow rate therethrough during operation. A bleed assembly is provided to include a bleed flow machine and a machine load. The bleed flow machine is provided in fluid communication with the compressor section of the turbomachine and configured to drive the machine load. A machine outlet in fluid communication with the bleed assembly provides a bleed flow therethrough during operation of the gas turbine engine, the bleed flow defining a bleed mass flow rate. A compressor section of the turbomachine is configured to provide the bleed flow through the bleed flow machine and the machine outlet to an aircraft flow assembly, wherein the bleed mass flow rate is at least twelve percent (12%) of the core mass flow rate.

A turbo machine including a plenum is formed within a double wall structure including an opening configured to provide fluid communication of a first flow of fluid between the plenum through the double wall structure, and an outer wall forming a passage configured to receive a second flow of fluid separate from the first flow of fluid, wherein a flowpath structure is formed at least in part within an inner wall, the flowpath structure configured to receive a third flow of fluid therethrough, the third flow of fluid separate from the first flow of fluid, the flowpath structure comprising an exit opening configured to provide fluid communication from the flowpath structure to the flowpath.

A turbo machine including a plenum is formed within a double wall structure including an opening configured to provide fluid communication of a first flow of fluid between the plenum through the double wall structure, and an outer wall forming a passage configured to receive a second flow of fluid separate from the first flow of fluid, wherein a flowpath structure is formed at least in part within an inner wall, the flowpath structure configured to receive a third flow of fluid therethrough, the third flow of fluid separate from the first flow of fluid, the flowpath structure comprising an exit opening configured to provide fluid communication from the flowpath structure to the flowpath.

An aircraft engine nacelle comprising an icing protection system and an icing protection method for such an aircraft engine nacelle. The aircraft engine nacelle comprises an air inlet comprising a lip, a tubular air inlet piece and an icing protection system. The icing protection system comprises an icing prevention means powered continuously by a first electrical energy source and wholly or partly covering the lip, a de-icing means powered by a second electrical energy source covering the tubular air inlet piece and a controller configured to acquire a current total air temperature value, and control the second electrical energy source as a function of the current total air temperature value.

An aircraft engine nacelle comprising an icing protection system and an icing protection method for such an aircraft engine nacelle. The aircraft engine nacelle comprises an air inlet comprising a lip, a tubular air inlet piece and an icing protection system. The icing protection system comprises an icing prevention means powered continuously by a first electrical energy source and wholly or partly covering the lip, a de-icing means powered by a second electrical energy source covering the tubular air inlet piece and a controller configured to acquire a current total air temperature value, and control the second electrical energy source as a function of the current total air temperature value.

An aircraft propulsion assembly includes a turbine engine surrounded by a nacelle with an annular air-intake lip extending around the turbine engine by two annular walls, inner and outer, respectively, intended for being swept across by air flows at least when the aircraft is in flight. The inner and outer walls each includes or supports at least one network of pipes forming heat exchangers. The inner wall pipe network having liquid outlet connected with a liquid intake of the outer wall pipe network. The propulsion assembly further includes means for circulating the liquid, connected to at least one liquid intake of the network of pipes of the inner wall.

A pressure regulating valve assembly includes: a valve having an upstream side receiving an input flow and a downstream side providing an output flow, an actuator for opening and closing the valve, including partially opening the valve, and a regulator controlling the actuator to open, close or partially open the valve. The regulator includes a sense pressure port, wherein pressure at the port is maintained constant by the regulator. A chamber has a first entry orifice, a second entry orifice and an exit orifice. The first entry orifice is connected to the upstream side, the second entry orifice is connected to the downstream side, and the exit orifice is connected to the port. The exit orifice provides that the pressure at the exit orifice lies between the pressure at the first entry orifice and the pressure at the second entry orifice.