38results about How to "Reduce turbulence noise" patented technology

An inlet duct, an induction system, and a system are disclosed for directing an inlet flow into an inlet compressor for use in an internal combustion engine. An example inlet duct may include one or more relief features disposed on an inner surface of the inlet duct. The one or more relief features may be made integral with the inlet duct. The one or more relief features may be disposed to protrude into the inlet flow to cause the inlet flow to swirl before reaching the inlet compressor.

A double deck elevator comprising an upper cage and a lower cage vertically movable together in a hositway, wherein a space between the upper cage and the lower cage is covered by covers. The covers guide airflow flowing around the space to reduce air turbulence noise, and consequently the quietness and comfortableness in the cages is improved.

The invention provides an air outlet device. The air outlet device comprises a hub; the fan blades are arranged on the hub, and the fan blades are arranged in a double-end symmetrical wing shape. The fan blades are arranged to be in a double-end symmetrical wing shape, so that when the fan blades are driven by external force to rotate in different rotating directions, the symmetrically-arranged fan blades are the same in blade shape in different windward directions, it is guaranteed that the pneumatic states of the fan blades are the same when the fan blades rotate forwards and backwards, and the air outlet amount of the two sides of the hub is effectively balanced when the fan blades rotate forwards and backwards; and the blowing requirements can be met in two directions during forward and reverse air outlet.

The present application provides a fan assembly and a communication device. The fan assembly includes a casing for accommodating an axial flow fan, and the axial flow fan of the fan assembly is arranged in the casing during installation. In addition, the casing is also connected with an air guide cover, and the air guide cover is provided with an air inlet, and a rectifying grid is arranged in the air inlet of the air guide cover. When in use, the non-uniformity of the airflow entering from the air inlet on the plane will generate a strong vortex, thereby increasing the broadband and narrow-band noise of the axial fan. The air supply volume can be increased by setting the axial flow fan, and the rectification grid realizes the function of air inlet guide and flow equalization, thereby reducing the turbulent flow noise of the fan assembly at the air inlet, thereby reducing the noise of the entire axial flow fan. And the rectifying grid is set in the air inlet, which reduces the occupied space.

The invention discloses an air guide ring and an air conditioner outdoor unit, which relate to the technical field of refrigeration devices. The air guide ring and the air conditioner outdoor unit are invented to solve the problem of generation of turbulence noise since the edge of an air outlet of the air guide ring in the prior art generates whirl airflow. The air guide ring comprises an air guide ring main body; the air guide ring main body encircles to form an air guide duct, the air guide ring main body comprises an outer layer side wall and an inner layer side wall, an annular air guide groove is formed between the outer layer side wall and the inner layer side wall, one end of the annular air guide groove close to the inlet of the air guide duct is closed, and one end of the annular air guide groove away from the inlet of the air guide duct is open. The air guide ring can be used for guiding the airflows generated by an axial flow fan.

The invention relates to a high-pressure cooling fan for a high-flow low-noise fuel cell vehicle, which includes a hub, fan blades, an outer ring and a wind protection ring, the hub and the outer ring are coaxially arranged, and the fan blades are fixed between the hub and the outer ring and rotate The axis is centered and distributed at equal intervals in the circumferential direction. The wind protection ring is arranged outside the outer ring. The fan blades include a plurality of two-dimensional blades. The two-dimensional blades are inclined at a certain blade installation angle. The two-dimensional blades The three-dimensional blade shape is projected onto the corresponding circumferential cylindrical section. The three-dimensional blade shape from the root to the tip of the fan blade is superimposed on the inner side of the outer ring along the set leading edge stacking line. The installation of each two-dimensional blade shape The relationship between the angle and the normalized radius of the cylindrical section of the two-dimensional airfoil is a polynomial function, and the normalized radius is the ratio of the radius of the cylindrical section of the three-dimensional airfoil to the radius of the cylindrical section at the blade tip of the fan blade. Compared with the prior art, the fan of the invention improves gas flow and effectively suppresses turbulent noise, and has low-noise and high-flow characteristics at high rotational speed.

The invention discloses an efficient and environment-friendly automobile muffler and a sound elimination method thereof. The efficient and environment-friendly automobile muffler comprises an outer barrel body and a sound absorption cavity formed in the outer barrel body, wherein a perforated air inlet tube of which air hole arrays are distributed at the two ends is arranged in the sound absorption cavity; an air inlet cavity baffle plate is arranged in the middle of the perforated air inlet tube; with the air inlet cavity baffle plate adopted as the boundary, the sound absorption cavity is divided into an air inlet cavity surrounded by first-grade foamed aluminium sound absorbing boards, and a middle cavity surrounded by second-grade foamed aluminium sound absorbing boards; and a middle cavity outer barrel is arranged at the outer parts of the second-grade foamed aluminium sound absorbing boards in a sleeving manner. According to the muffler structure, gases need to pass through multi-level damping loops composed of the perforated air inlet tube, the first-grade foamed aluminium sound absorbing boards, the second-grade foamed aluminium sound absorbing boards, the movable baffle plate, and the like, so that gases with higher kinetic energy are enabled to flow through more loops, the turbulent noise is effectively reduced, and a relatively high sound elimination capacity is achieved.