Cooling of gas turbine engine accessories using air inlet located on a keel beam

A gas turbine engine for an aircraft, the engine including:

• an engine core comprising a turbine, a compressor, and a core shaft, the core shaft connecting the turbine to the compressor;
• core casings surrounding the engine core;
• an aerodynamic cowl which surrounds the core casings;
• a propulsive fan located upstream of the engine core, the fan configured to generate a core airflow which enters the engine core and a bypass airflow which enters a bypass duct surrounding the aerodynamic cowl;
• and
• an engine accessory mounted in a space between the core casings and the aerodynamic cowl;
• a circumferential row of outer guide vanes located in the bypass duct rearwards of the propulsive fan, the outer guide vanes extending radially outwardly from an inner ring, the inner ring defining a radially inner surface of the bypass duct;
• a fixture located rearwardly from the inner ring, wherein the fixture provides a connection point for a mounting pylon,
• wherein the aerodynamic cowl is rearwards of the inner ring and includes a first door section and a second door section, wherein the first door section and the second door section are located on respective and opposite sides of the gas turbine engine, each door section being pivotably openable about a respective upper edge thereof to enable maintenance access to the engine core, the aerodynamic cowl further including a keel beam which extends rearwardly from the inner ring, wherein the keel beam is diametrically opposed to the fixture, wherein the keel beam provides latching formations for latching to a first lower edge of the first door section and a second lower edge of the second door section when the respective door sections are closed;
• wherein the gas turbine engine further includes:
• a ventilation inlet located on a radially outer surface of the keel beam to receive a portion of the bypass airflow as a cooling flow for the engine accessory, the ventilation inlet being configured to convert a portion of kinetic energy of the bypass flow received therein into a pressure rise such that the pressure of the cooling flow is increased relative to the pressure of the bypass airflow;
• and
• a manifold in fluid communication with the ventilation inlet to collect the cooling flow therefrom, the manifold having a plurality of exhaust holes through which the cooling flow leaves the manifold to impinge upon and thereby cool the engine accessory.