A vehicle includes a main body and a gas generator producing a gas stream. At least one fore conduit and tail conduit are fluidly coupled to the generator. First and second fore ejectors are fluidly coupled to the at least one fore conduit. At least one tail ejector is fluidly coupled to the at least one tail conduit. The fore ejectors respectively include an outlet structure out of which gas from the at least one fore conduit flows. The at least one tail ejector includes an outlet structure out of which gas from the at least one tail conduit flows. First and second primary airfoil elements have leading edges respectively located directly downstream of the first and second fore ejectors. At least one secondary airfoil element has a leading edge located directly downstream of the outlet structure of the at least one tail ejector.

Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.

Fluid systems are described herein. An example embodiment of a fluid system has a lengthwise axis, a chord length, a first body portion, a second body portion, a spacer, and a fluid pressurizer. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. The first body portion defines a cavity that is sized and configured to filter debris that enters the channel during use and provide a mechanism for removing the debris from the system.

Example active flow control systems and methods for aircraft are described herein. An example method includes supplying pressurized air to a plurality of nozzles. The nozzles arranged in an array across a control surface of an aircraft, and the nozzles are oriented to eject the pressurized air in a substantially streamwise direction. The method further includes activating the nozzles to eject the pressurized air in sequence to create a wave of air moving in a spanwise direction across the control surface.

Fluid systems are described herein. An example embodiment of a fluid system has a first body portion, a second body portion, a plurality of supports, a plurality of fluid pressurizers, and a plurality of ducts. The first body portion and the second body portion cooperatively define an injection opening, a suction opening, and a channel that extends from the injection opening to the suction opening. The fluid pressurizer is disposed within the channel cooperatively defined by the first body portion and the second body portion. Each duct of the plurality of ducts is disposed within the channel cooperatively defined by the first body portion and the second body portion.

A propulsion system coupled to a vehicle. The system includes an ejector having an outlet structure out of which propulsive fluid flows at a predetermined adjustable velocity. A control surface having a leading edge is located directly downstream of the outlet structure such that propulsive fluid from the ejector flows over the control surface.

A strut includes a strut body extending in a radial direction and defining an airfoil shape in cross-section perpendicular to the radial direction. The airfoil shape includes a leading edge and a trailing edge. An extraction inlet is defined through an exterior surface of the strut body, in fluid communication with an internal conduit of the strut body. An injection outlet is defined through the exterior surface of the strut body, in fluid communication with the internal conduit for fluid communication through the internal conduit from the extraction inlet to the injection outlet.

A propulsion system includes a source of compressed fluid, at least one thruster in fluid communication with the source, at least one turbine in fluid communication with the source and coupled to a propeller, and an apparatus for selectively providing the compressed fluid to one or both of the at least one thruster and the at least one turbine.

A method of controlling an aircraft bleed may include the steps of monitoring a temperature of a precooled airflow exiting a precooler, and determining a status of a wing anti-ice system of an aircraft. The wing anti-ice system may be configured to receive the precooled airflow from the precooler. The method may further comprise the steps of determining whether an engine operating condition of the aircraft is within an icing envelope, selecting a temperature set point for the precooled airflow based on the status of the wing anti-ice system and whether the aircraft is within an icing envelope, and modulating a fan airflow from a fan to the precooler to adjust the temperature of the precooled airflow to the temperature set point.

Methods and systems for controlling a fluid flow field near a surface are disclosed. In some embodiments, the system includes an array of oscillating bodies disposed on the surface to provide physical modification to the flow field. Fluid jets are also emitted from an outlet in the oscillating body to provide virtual modification of the flow field through momentum addition. Fluid jet sources, including synthetic jet generators such as piezoelectric drivers and sources of compressed fluids such as air or water, are positioned to be in fluid communication with the outlet at intervals during the oscillation of the oscillating body. Controlling the oscillation amplitude and frequency of the body, as well as the location of oscillating body outlets and frequency of fluid jet emission, have advantageous effects for the surface such as improved heat transfer properties and reduction in structural vibration and noise.