摘要:
A system and method is described generally for deforming a first surface of a body and deforming a second surface of a body to alter a fluid flow in order to change the characteristics of the fluid flow about the body and thereby control the fluid dynamic forces on the body.
摘要:
A method of controlling an aircraft, missile, munition or ground vehicle with plasma actuators, and more particularly of controlling fluid flow across their surfaces or other surfaces which would benefit from such a method, includes the design of an aerodynamic plasma actuator for the purpose of controlling airflow separation over a control surface of a aircraft, missile, or a ground vehicle, and a method of determining a modulation frequency for the plasma actuator for the purpose of fluid flow control over these vehicles. Various embodiments provide steps to increase the efficiency of aircraft, missiles, munitions and ground vehicles. The method of flow control reduces the power requirements of the aircraft, missile, munition or ground vehicle. These methods also provide alternative aerodynamic control using low-power hingeless plasma actuator devices.
摘要:
The invention relates to a flying object which moves with a transonic or supersonic velocity. The inventive flying object comprises a main body, a streaming element and a holding element. The holding element holds the streaming element distant from the main body. The streaming element is permeable for the airstream. For one embodiment the streaming element is built with a porous material. The streaming element has an outer surface with the shape of a cone or a truncated cone. The holding element holds the streaming element in an orientation with the cone opening towards the airstream.
摘要:
An aircraft includes a surface over which an airflow passes. A plasma actuator is configured to generate a plasma above the surface, the plasma coupling a directed momentum into the air surrounding the surface to reduce separation of the airflow from the surface. A method of reducing separation of an airflow from a surface of an aircraft includes generating a plasma in air surrounding the surface at a position where the airflow would separate from the surface in the absence of the plasma.
摘要:
Systems and methods for controlling flow with electrical pulses are disclosed. An aircraft system in accordance with one embodiment includes an aerodynamic body having a flow surface exposed to an adjacent air stream, and a flow control assembly that includes a first electrode positioned at least proximate to the flow surface and a second electrode positioned proximate to and spaced apart from the first electrode. A dielectric material can be positioned between the first and second electrodes, and a controller can be coupled to at least one of the electrodes, with the controller programmed with instructions to direct air-ionizing pulses to the electrode, and provide a generally steady-state signal to the electrode during intervals between the pulses.
摘要:
A rotary-wing system which generates a directed ion field to propel a fluid along a rotary-wing to control at least one boundary layer characteristic.
摘要:
A system and method is described generally for deforming a first surface of a body and deforming a second surface of a body to alter a fluid flow in order to change the characteristics of the fluid flow about the body and thereby control the fluid dynamic forces on the body.
摘要:
This patent provides for a method and apparatus for mitigating the formation of concentrated wake vortex structures generated from lifting or thrust-generating bodies and maneuvering control surfaces wherein the use of contour surface geometries promotes vortex-mixing of high and low flow fluids. The method and apparatus can be combined with various drag reduction techniques, such as the use of riblets of various types and/or compliant surfaces (passive and active). Such combinations form unique structures for various fluid dynamic control applications to suppress transiently growing forms of boundary layer disturbances in a manner that significantly improves performance and has improved control dynamics.
摘要:
A flow surface (16), e.g. on a swept aircraft wing, has a three-dimensional boundary-layer flow. The surface is defined by a spanwise direction (z) and a chordwise direction (x). In or on the flow surface excitation locations (22) are arranged, exciting primary disturbances. The disclosure is characterized in that the excitation locations (22) are arranged such that benign steady primary disturbances are excited and maintained on a sufficiently-high amplitude level as longitudinal vortices respectively crossflow vortices, suppressing naturally growing nocent primary disturbances by a non-linear physical mechanism. The benign primary disturbances preserve a laminar flow, such that unsteady secondary disturbances, which may initiate turbulence and which, otherwise, are excited in streamwise direction by nocent primary vortices, are suppressed or at least stabilized.
摘要:
A method and apparatus using localized heating to encourage laminar flow along an airfoil exterior surface. The airfoil includes a leading edge (24), a controlled surface (18), and an uncontrolled surface (20). The present invention localized heating system (38) includes a heat source (40) located within the airfoil and connected to the leading edge (24), and a heat sink (42) positioned aft of the heat source (40) and arranged to transfer heat from the airfoil controlled surface (18) to the uncontrolled surface (20). The heat sink (42) preferably expels heat along uncontrolled surface adjacent to turbulent air flow. In one preferred embodiment as applied to a generally circular aircraft engine nacelle (12), the heat source (40) is an electro-thermal heat source (44) having a high resistance wire embedded in a composite material leading edge structure (50), and the heat sink (42) is a heat pipe (52) having a wicking material (58) and a vaporizing agent (60). A method of encouraging laminar flow about a controlled surface of an airfoil is further provided. The method includes heating (61) the outer surface near the leading edge region, drawing (62) heat from a controlled surface downstream of the heated surface, and expelling (63) heat along the an uncontrolled surface.