Particle separation system upstream of a heat exchanger in a gas turbine engine

A gas turbine engine comprising:

• a heat exchanger;
• and
• a particle separation system comprising at least one inertial particle separator spaced apart from the heat exchanger or integrated as a unitary piece with the heat exchanger, the at least one inertial particle separator being disposed upstream of the heat exchanger, wherein the at least one inertial particle separator is configured and arranged:
• to direct a first fluid flow containing a first amount of particles to an inner passage provided at a hub of the heat exchanger, an outer passage provided at a tip of the heat exchanger, or both, the hub and the tip being located at a radial periphery of the heat exchanger;
• and
• to direct a second fluid flow containing substantially no particles or a second amount of particles to a central portion of the heat exchanger to cool down a fluid circulating within the heat exchanger, the second amount of particles being substantially less than the first amount of particles,
• wherein the at least one inertial particle separator comprises one or more louvers spaced apart from the heat exchanger or integrated as a unitary piece with the heat exchanger, the one or more louvers being disposed upstream of the heat exchanger,
• wherein the one or more louvers are configured and arranged:
• to direct the first fluid flow containing the first amount of particles to the inner passage provided at the hub of the heat exchanger, the outer passage provided at the tip of the heat exchanger, or both;
• and
• to direct the second fluid flow containing substantially no particles or the second amount of particles to the central portion of the heat exchanger to cool down the fluid circulating within the heat exchanger.