11results about How to "Guaranteed aerodynamic performance" patented technology

The invention belongs to the technical field of aircraft cockpit windshield glass structure design, and particularly relates to an aircraft cockpit windshield glass structure which comprises an electromagnetic film, outer-layer glass, inner-layer glass, a metal frame, a metal sinking frame and a curved-surface wave-transparent fairing. The electromagnetic film is positioned between the outer-layer glass and the inner-layer glass; the inner-layer glass is arranged in the metal frame; the electromagnetic film is in flush contact with the outer side surface of the metal frame; the metal sinking frame is mounted in the windshield window, and the cross section of the metal sinking frame is L-shaped; the metal frame is arranged in the L-shaped opening of the metal sinking frame, the outer side surfaces of the metal frame and the metal sinking frame are flush and contacted with the aircraft body surface skin, and the outer-layer glass protrudes out of the aircraft body surface skin; the curved-surface wave-transparent fairing surrounds the periphery of the outer-layer glass and is in smooth transition between the outer-layer glass and the surface skin of the machine body.

The invention provides a cross-flow fan blade and a cross-flow fan with the cross-flow fan blade, the cross-flow fan blade comprises a plurality of middle-section fan blades which are connected in sequence, and each middle-section fan blade comprises a disc, a connecting structure and a plurality of blades; each blade is provided with a first end and a second end, the first ends are connected with the disc, the second ends extend in the axial direction of the disc, the second ends of the adjacent blades are connected through a connecting structure, the end face, away from the disc, of the connecting structure is a first end face, and the first end face is connected with the disc of the adjacent middle-section fan blade. The first end face of the first middle-section fan blade is connected with the annular groove of the second middle-section fan blade, and the blade of the first middle-section fan blade is connected with the blade groove of the second middle-section fan blade. The connecting structures are arranged at the second ends of the blades, so that the connecting strength between the blades can be enhanced, the whole fan blade is more stable in the operation process, and the phenomenon that the whole fan blade is prone to deformation in the placement process is avoided.

The invention belongs to the technical field of aerospace, and discloses a vertical and horizontal tail butt joint fairing connecting structure and an aircraft, a vertical and horizontal tail butt joint fairing skin is fixedly connected with a horizontal tail upper wall plate, a vertical tail left wall plate is fixedly connected with a vertical tail end rib, and an inserting plate is connected to the position, connected with the vertical tail end rib, of the inner side of the vertical and horizontal tail butt joint fairing skin; a base plate is fixedly connected between the vertical tail left wall plate and the vertical and horizontal tail butt joint fairing skin on the vertical tail end rib, an insertion cavity allowing the insertion plate to be inserted is reserved between the base plate and the vertical tail end rib, and the insertion plate is inserted into the insertion cavity and can slide in the insertion cavity. The outer surface of the vertical fin left wall plate outer surface base plate is flush with the outer surface of the vertical and horizontal tail butt joint fairing skin. According to the vertical and horizontal tail butt joint fairing, the skin and the vertical tail end ribs are in flexible connection, so that the fairing can have a certain deformation coordination capacity, deformation is limited by flexible connection to be further transmitted to a vertical tail structure, and then unreasonable deformation can be prevented from damaging the aerodynamic configuration and increasing resistance.

The present invention discloses a counter-rotating fan, the counter-rotating fan comprises a first-stage impeller and a second-stage impeller which are coaxial and spaced apart, the first-stage impeller and the second-stage impeller have opposite rotation directions, the first-stage impeller comprises a plurality of first blades arranged circumferentially, the edges of both sides of each first blade in the circumferential direction are respectively a first leading edge and a first trailing edge, the first leading edge and the first trailing edge are both bent in the radial direction from inside to outside toward the rotation direction, the second-stage impeller comprises a plurality of second blades arranged circumferentially, the edges of both sides of each second blade in the circumferential direction are respectively a second leading edge and a second trailing edge, the second leading edge and the second trailing edge are both bent in the radial direction from inside to outside toward the rotation direction. The counter-rotating fan according to the embodiment of the present invention improves the efficiency of the counter-rotating fan, and reduces the rotation noise of the second blade while ensuring the aerodynamic performance of the second blade.

The invention discloses a noise reduction structure and a range hood comprising the noise reduction structure, the noise reduction structure is arranged in a case of a fan system, the noise reduction structure is arranged at a volute tongue of a volute of the fan system, the noise reduction structure is provided with a noise reduction cavity in a penetrating mode in the axial direction of the volute, and the noise reduction cavity is communicated with the volute tongue of the volute. The noise reduction cavity communicates with the first air inlet area and the second air inlet area of the volute, and the cross section area of a cavity of the noise reduction cavity accounts for 20%-35% of the cross section area of the noise reduction structure. The noise reduction structure is arranged at the volute tongue, so that the operation noise of the fan system is reduced. By arranging the noise reduction cavity, the first air inlet area and the second air inlet area are communicated through the noise reduction cavity, the flowing resistance of airflow is improved, the adverse effect of the noise reduction structure on the flowing state in the case is weakened, and the inner wall of the noise reduction cavity can also be used for absorbing noise; in this way, the noise reduction effect is improved, and the aerodynamic performance of the fan system is guaranteed by increasing the sound absorption area of the noise reduction structure.

The invention belongs to the field of propellers, and discloses a noise reduction method for applying an epoxy resin coating on the surface of a propeller, which comprises the following steps of: adhering polyurea, polyurethane or epoxy resin to the surface of the propeller in manners of spraying, dip-coating, brush coating, spot coating and the like to form a compact protective film and hemispherical turbulent flow bulges, changing eddy current on the surface of the propeller, and realizing noise reduction. The protrusions are arranged to two thirds of the radius along the front edge of the propeller pressure face, and the size of the protrusions can be optimized according to working conditions. The method is simple and easy to implement, the noise sound pressure level is effectively reduced, environmental noise pollution is reduced, and the aircraft sound stealth performance is improved. Experiments show that under the rotating speed of 2000 rpm, the noise reduction effect is remarkable, and the thrust loss is only 0.37%. According to the noise reduction method, the aerodynamic noise of the propeller can be effectively reduced on the premise of ensuring the aerodynamic performance of the propeller, the sound concealment performance of an aircraft is improved, the noise pollution to the surrounding environment is reduced, and the method is simple, easy to implement and easy to popularize.

The application discloses a novel foldable blade, which comprises a blade body, the blade body is divided into a pressure surface and a suction surface, the blade body is a three-section structure, a folding structure is connected between every two adjacent blades, a locking structure is arranged on the end surface of every two adjacent blades, a folding area compensation structure is arranged on the suction surface, the folding structure is used for driving the blade body to fold or unfold, when the blade body is unfolded, the three-section blades form a linear shape, the end surfaces of every two adjacent blades are tightly attached to each other and are locked through the locking structure, when the blade body is folded, the two blades located at the two ends of the three-section blades are folded towards the suction surface of the blade located in the middle, forming a U-shaped structure, and the folding area compensation structure is used for preventing the suction surfaces of the two adjacent blades from colliding. The application can effectively shorten the length of the blade, reduce the load of the blade tip which is easy to be damaged, and guarantee the aerodynamic performance and structural safety of the blade.

The utility model discloses a tensioning device for a wind power blade flexible assembly. The tensioning device comprises a supporting component, a side cable fixing component and a tensioning adjusting component. The supporting component comprises an upper shape-following support and a tensioning fixing frame, the upper shape-following support comprises multiple sections of shape-following pipe fittings, the multiple sections of shape-following pipe fittings are tightly attached to the appearance structure of the blade shell assembly to be arranged and spliced into a whole, and the tensioning fixing frame is arranged below the upper shape-following support. A plurality of mounting holes are circumferentially formed in the tensioning fixing frame at preset intervals; a first notch is formed in one end of the side cable fixing component, and a second notch matched with a side cable of the blade flexible assembly is formed in the other end of the side cable fixing component. One end of the tensioning adjusting component is arranged in the first notch, and the other end of the tensioning adjusting component penetrates through the mounting hole and then is connected with the tensioning fixing frame; according to the utility model, the tensioning force of the flexible blade assembly is adjusted, and the flexible blade assembly is tensioned again, so that the tensioned flexible blade assembly can adapt to a wind power blade framework.

This invention discloses a two-dimensional beamforming mechanically scanned UAV-borne conformal metasurface antenna and its shaping method. The metasurface antenna includes a feed antenna and a transmissive metasurface composed of multiple metasurface units. Each metasurface unit includes a first metal layer stacked with an outer circular arc segment and an inner circular arc segment that share a common center. The inner circular arc segment includes a first inner circular arc segment and a second inner circular arc segment that are not connected. The middle portion of the outer circular arc segment is connected to a third rectangular segment. The first inner circular arc segment and the second inner circular arc segment are mirror-symmetric about a first line of symmetry. The orthographic projection of the first metal layer onto a dielectric substrate is a first orthographic projection, and the orthographic projection of the second metal layer onto the dielectric substrate is a second orthographic projection. The first and second orthographic projections partially coincide, share a common center, and are mirror-symmetric about a second line of symmetry. The antenna provided by this invention simultaneously excites both electrical and magnetic responses in the metasurface units, improving the transmission performance of the transmissive metasurface unit.

The application provides a bionic aircraft, and relates to the technical field of aircrafts, which comprises a fuselage and main wing systems arranged on both sides of the middle part of the fuselage, each main wing system comprising a first driver, a first rocker arm, a connecting rod, a connecting seat and a plurality of bionic wing ribs, the first driver being fixedly connected to the fuselage, one end of the first rocker arm being connected to the output shaft of the first driver, the other end of the first rocker arm being hingedly connected to one end of the connecting rod, one end of the connecting seat being hingedly connected to the other end of the connecting rod, the other end of the connecting seat being hingedly connected to the fuselage, and the plurality of bionic wing ribs being hingedly connected to the connecting seat, the first driver driving the first rocker arm to rotate, the first rocker arm driving the connecting seat to rotate around the fuselage through the connecting rod, and then driving at least part of the bionic wing ribs to rotate relative to the connecting seat to be unfolded and arranged in a radial manner, so that the aerodynamic performance, the control flexibility and the impact resistance are considered while the folding storage portability is maintained.

The invention relates to a partition sand prevention method and system for an integral axial flow blade disc, and belongs to the field of aero-engine compressor blade discs. The partition sand prevention method comprises the following steps that blades of a blade disc body are cleaned through ultrasonic waves, and oxide layers are removed; according to damage differences of different areas of the blade, a blade basin first damage area, a blade basin second damage area, a blade back first damage area, a blade back second damage area, a blade top damage area and a non-damage area are divided on the blade; according to the method, the areas are divided on the blade, and the anti-erosion coatings are sprayed on the damaged areas in stages, so that the anti-erosion coatings are sprayed on the damaged areas under the conditions that the thicknesses of the first damaged area of the blade basin and the first damaged area of the blade back are 12-20 microns and the thicknesses of the second damaged area of the blade basin, the second damaged area of the blade back and the damaged area of the blade top are 6-10 microns; the anti-erosion capacity of the blade disc body can be greatly improved, and meanwhile the aerodynamic performance and the strength requirement of the blade disc body can be guaranteed.