Systems, methods, lift fans, and aircraft involving active flow control of a ducted fan or fan-in-wing configuration are described.

An airflow adjusting apparatus includes an airflow generator, a state detector, and a controller. The airflow generator is configured to generate a control airflow to cause the control airflow to join an around-vehicle airflow formed around a vehicle body of a traveling vehicle. The airflow generator is configured to vary a flow direction of the control airflow with respect to a surface of the vehicle body. The state detector is configured to detect a state of the around-vehicle airflow. The controller is configured to vary the flow direction of the control airflow on the basis of the state of the around-vehicle airflow detected by the state detector.

A removable passive airflow oscillation device can be disposed within a pressurized wing structure utilized as a plenum. The passive airflow oscillation device can be a removable insert disposed into exterior vehicle surfaces with pressurization of a sealed chamber to provide the airflow. The device can include a cavity configured to receive the airflow from an ingress opening, direct the airflow therethrough to generate a predetermined oscillating airflow, and expel the oscillatory airflow from the egress opening. The removable passive airflow oscillation devices can provide quick and simple replacement and maintenance of damaged or clogged devices. The aft chamber of the flap seal can be sealed and pressurized to serve as a plenum providing the airflow to the actuators. The device can receive airflow, such as compressor air, and expel an oscillating airflow. Because each device is self-contained the number of devices and location thereof can vary by application.

A propulsion system coupled to a vehicle. The system includes a diffusing structure and a conduit portion configured to introduce to the diffusing structure through a passage a primary fluid produced by the vehicle. The passage is defined by a wall, and the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid. A constricting element is disposed adjacent the wall. An actuating apparatus is coupled to the constricting element and is configured to urge the constricting element toward the wall, thereby reducing the cross-sectional area of the passage.

The present disclosure relates to a thermal emissivity control system. The system may have a segmented array that makes use of a thermally conductive base layer configured to be connectable to an external heat generating subsystem, with the base layer including a thermally emissive surface. The array may also have a plurality of actuation elements at least one of positioned on or adjacent to the thermally emissive surface. A plurality of movable shutter elements is disposed adjacent one another in a grid pattern, and controlled in movement by the actuation elements to create gaps of controllably varying dimension therebetween. The shutter elements control at least one of a magnitude of, or direction of, thermal radiation through the gaps.

A fluidic device includes a channel in which a fluid flows, and an ultrasonic element generating standing wave in the fluid within the channel by applying ultrasonic wave to the fluid, wherein the channel has a first portion formed using a resin material having a first reflectance of ultrasonic wave propagating in the fluid less than a predetermined value and a second portion having a second reflectance of ultrasonic wave propagating in the fluid equal to or more than the predetermined value, and the second portion is placed on two different surfaces along a flow direction of the fluid within the channel.

The device for preventing the formation of paraffin and asphaltene sediments and for the reduction of the viscosity of crude oil for use at an eruptive oil well, an oil well with pumpjack or for use at a pipeline, the stated device including six identical serially connected modules. Each module has an inlet spout and outlet spout. Crude oil under pressure passes through modules and simultaneously is in contact with different alloys. The device's elements consist of four different alloys that affect the crude oil while it passes through modules under pressure in the manner that it prevents the formation of paraffin and asphaltene deposits inside the pipeline or eruptive oil wells or oil wells with pumpjacks.

A lift control device actively controls the lift force on a lifting surface. The device has a protuberance near a trailing edge of its lifting surface, which causes flow to separate from the lifting surface, generating regions of low pressure and high pressure which combine to increase the lift force on the lifting surface. The device further includes a means to keep the flow attached around the protuberance or to modify the position of the protuberance in response to a command from a central controller, so as to provide an active control of the lift between a maximum value and a minimum value.

An active drag-reduction system has first 22 and second 24 fluid outlets located on a vehicle 10 adjacent to a low pressure (drag) region 12, wherein fluid ejected from the second fluid outlet 24 is at a higher pressure/ejection velocity than from the first fluid outlet 22. Turbulent and/or low pressure regions adjacent to vehicles are not uniform, but rather have a varying intensity. For instance, the centre of a region may have a lower pressure and/or more turbulent nature than the periphery of the region. The system injects relatively higher pressure air or relatively higher speed air into the relatively lower pressure/more turbulent part of the low pressure/turbulent region, and relatively lower pressure air or relatively lower speed air into the relatively higher pressure/less turbulent part of the low pressure/turbulent region, compared to each other.

A coolant equalizing reservoir for arrangement in a coolant circuit, having: a reservoir housing, a vortex chamber in the reservoir housing, a feed line for introducing coolant into the reservoir housing, and an outflow aperture for discharging coolant from the reservoir housing, where the feed line discharges into the vortex chamber, and wherein the vortex chamber is defined by a wall protruding from a base-wall section of the reservoir housing along a vortex chamber's axis, encircling the vortex chamber's axis in a closed manner, which in every direction orthogonal to the vortex chamber's axis is arranged at a distance from the reservoir housing.