4results about How to "Guaranteed aerodynamic performance" patented technology

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 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.

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.