A flow body for an aircraft includes a recess in a surface of the flow body, a first structural component with a porous material and may also include a second structural component with a porous material. The recess includes a front recess region and a rear recess region. The first structural component is arranged in, or on, the front recess region and the second structural component may be arranged in, or on, the rear recess region. An aircraft having the flow body, a weapons system having the flow body and a method for manufacturing a flow body for a vehicle are also described.

An ultrasonic airflow severing resistance reducing device for vehicles, including an airflow severing blade assembly, shock-absorbing installation assemblies, ultrasonic vibration components, and a rubber sealing ring assembly; a bottom portion of the airflow severing assembly is provided with an accommodating cavity; a top end of each shock-absorbing installation assembly is fixedly connected to an inner cavity wall of the accommodating cavity; a bottom end of each shock-absorbing installation assembly is formed with a fixed installation bottom portion; the ultrasonic vibration components are installed on the inner cavity wall; the rubber sealing ring assembly is arranged and installed on the airflow severing blade assembly. The ultrasonic vibration components drive the airflow severing blade assembly to generate high frequency ultrasonic vibration to sever airflow.

A radar-absorbing fiber-reinforced structure includes a fiber composite discharging part. The fiber composite discharging part includes a first electrode part and a second electrode part, which are spaced apart from each other by a dielectric layer and receive different voltages. The fiber composite discharging part is configured to discharge plasma in response to a voltage difference thereby changing a reflected wave or transmitted wave of a radar incident on the radar-absorbing fiber-reinforced structure to reduce reflectivity of the radar. At least one of the first electrode part and the second electrode part include a conductive fiber having a tensile strength equal to or more than 0.5 GPa.

An apparatus, system and method for generating ionosonic lift is provided. First and second control electrodes are attached in a spaced-apart relation proximal to a top surface of a wing. An alternating potential applied to the first and second control electrodes alternately attracts and repels ions of a fluid in which the wing is immersed, causing a reciprocating flow of the ions of the fluid and of neutral molecules between the first and second control electrodes. The reciprocating flow of the ions and neutral molecules causes a reduction in pressure at the top surface of the wing, resulting in net lift applied to the wing under the Bernoulli relation.

A vehicle includes a surface for contacting a fluid medium through which the vehicle is propelled. The vehicle also includes an array of transducers and a controller. The transducers in the array are arranged across the vehicle's surface for generating pressure waves in the fluid medium. Each transducer in the array is arranged to vibrate for generating a respective pressure wave, which propagates away from the surface in the fluid medium. The controller vibrates the transducers in the array so that the pressure waves control the drag of the vehicle from the fluid medium.

Systems and methods are described herein to implement transverse momentum injection at low frequencies to directly modify large-scale eddies in a turbulent boundary layer on a surface of an object. A set of transverse momentum injection actuators may be positioned on the surface of the object to affect large-scale eddies in the turbulent boundary layer. The system may include a controller to selectively actuate the transverse momentum injection actuators with an actuation pattern to affect the large-scale eddies to modify the drag of the fluid flow on the surface. In various embodiments, the transverse momentum injection actuators may be operated at frequencies less than 10,000 Hertz.

An aircraft propulsion system with a drag reduction portion adapted to reduce skin friction on at least a portion of the external surface of an aircraft. The drag reduction portion may include an inlet to ingest airflow. The aircraft may also have an internally cooled electric motor adapted for use in an aerial vehicle. The motor may have its stator towards the center and have an external rotor. The rotor structure may be air cooled and may be a complex structure with an internal lattice adapted for airflow. The stator structure may be liquid cooled and may be a complex structure with an internal lattice adapted for liquid to flow through. A fluid pump may pump a liquid coolant through non-rotating portions of the motor stator and then through heat exchangers cooled in part by air which has flowed through the rotating portions of the motor rotor. The drag reduction portion and the cooled electric motor portion may share the same inlet.

An aircraft surface cover is provided. The aircraft surface cover includes a cover member that is configured to be removably secured to an aircraft structure. The cover member includes an exterior surface that has a microtextured surface including microtexture ribs that are configured to improve aerodynamic performance of the aircraft structure.

An ultrasonic airflow severing resistance reducing device for vehicles, including an airflow severing blade assembly, shock-absorbing installation assemblies, ultrasonic vibration components, and a rubber sealing ring assembly; a bottom portion of the airflow severing assembly is provided with an accommodating cavity; a top end of each shock-absorbing installation assembly is fixedly connected to an inner cavity wall of the accommodating cavity; a bottom end of each shock-absorbing installation assembly is formed with a fixed installation bottom portion; the ultrasonic vibration components are installed on the inner cavity wall; the rubber sealing ring assembly is arranged and installed on the airflow severing blade assembly. The ultrasonic vibration components drive the airflow severing blade assembly to generate high frequency ultrasonic vibration to sever airflow.

An ionic propulsion system for an aircraft having an airfoil includes a first conductor and a second conductor, the first conductor and the second conductor being disposed at least partially within the airfoil when not in use. The propulsion system includes an actuator for extending the first conductor and the second conductor from an end of the airfoil such that the first conductor and the second conductor are in the airstream of the aircraft, the first conductor being upstream of the second conductor in the airstream. The propulsion system includes a power supply for supplying current to the first conductor and the second conductor to ionize the air particles in the vicinity of the first conductor and the end of the airfoil to create a flow of the ionized particles from the first conductor toward the second conductor.