Particle separator using boundary layer control

A method comprising the following steps:

• (a) providing a particle separator comprising an inner wall, an outer wall and a splitter, wherein the inner and outer walls define an air intake passageway, and wherein the splitter is positioned between the inner and outer walls so as to define a scavenge air flow passageway connected to the intake passageway and a main air flow passageway connected to the intake passageway, the inner wall having a humped-shaped portion between the intake passageway and the main air flow passageway, the humped-shaped portion having a peak and a radius of curvature at any point on the hump-shaped portion of the inner wall after the peak corresponding to a degree of curvature of from about 30 to about 60 degrees;
• and
• (b) providing active boundary layer flow control along the inner wall after the peak and within the main air flow passageway by injecting a core mass flow along an inboard surface of the innerwall.

A method comprising the following steps:

• (a) providing a particle separator comprising an inner wall, an outer wall and a splitter, wherein the inner and outer walls define an air intake passageway, and wherein the splitter is positioned between the inner and outer walls so as to define a scavenge air flow passageway connected to the intake passageway and a main air flow passageway connected to the intake passageway, the inner wall having a humped-shaped portion between the intake passageway and the main air flow passageway, the humped-shaped portion having a peak and a radius of curvature at any point on the hump-shaped portion of the inner wall after the peak corresponding to a degree of curvature of from about 30 to about 60 degrees;
• and
• (b) providing active boundary layer flow control along the inner wall after the peak and within the main air flow passageway, wherein the active boundary layer flow control comprises removing a portion of the boundary layer from a core airflow at a suction area along the inner wall after the peak and within the main air flow passageway.