SU1071784A1 - Muffler of aerodynamic noise of gas flow - Google Patents

Abstract

AIRCRAFT CALLS In order to increase the noise attenuation efficiency, the fairing is installed in the pipe without a gap, and the perforation coefficient of the pipe is made equal to KnXD chi) 2of L, where D is the inner diameter of the housing,: .-: -ca, m; -; ,: о - internal diameter of the pipe, m; L - perforated length,:. , pipe section, m

Description

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FIELD OF THE INVENTION The invention relates to mechanical engineering, in particular to mufflers of aerodynamic noise of a gas flow.

Known silencer aerodynamic noise gas flow, comprising a housing, lined from the inside with sound-absorbing material, and a perforated tube installed in it with a central fairing made in the form of two perforated cones coaxial with the tube 111 with a common base.

However, due to the fact that the fairing is installed in a pipe with a gap, in a well-known silencer the gas flow does not participate in a complex vortex motion, which leads to a significant decrease in its energy state, which reduces the noise attenuation efficiency.

The purpose of the invention is to increase the efficiency of sound attenuation.

To achieve this goal, in an aerodynamic noise silencer of a gas flow comprising a casing lined with sound-absorbing material from the inside and a perforated pipe installed in it with a central fairing made in the form of two perforated cones coaxially with a pipe, the fairing is installed in the pipe without a gap the perforation coefficient of the pipe is made equal to

Kn () - 2dtL,

where b is the internal diameter of the body, m ct is the internal diameter of the pipe, m; L - perforated length

pipe section, m. The drawing shows the proposed muffler.

The muffler of aerodynamic noise of the flow of gases includes a housing 1, lined from the inside with sound-absorbing material 2, and installed in it

a perforated pipe 3 with a central fairing 4i. made in the form of two perforated cones coaxial with a pipe 3 with a common base and filled with sound-absorbing material 5, and the coefficient of perforation of the pipe is made equal

Kn () 2dL ,.

where 13 is the internal diameter of the housing, m d is the internal diameter of the pipe, m; L - length of perforated - pipe section, m

The silencer works as follows.

The gas flow flows around the central fairing 4, while the sound vibrations are partially absorbed by the sound-absorbing material 5 filling the fairing, then the flow is divided into vortex jets in the holes in the perforation of the pipe 3, which leads to an effective reduction of noise by reducing the energy of sound vibrations during crushing gas flow to the vortex formations and their interaction, as well as the absorption of sound waves by sound-absorbing material 2, which is covered inside the muffler body. The effect of noise suppression is enhanced by the second stage of gas crushing, which is passed by the gas flow on the way from the silencer body to the upper part of the perforated pipe.

Such an execution of the silencer allows effective suppression of the sound oscillations of the gas flow.

Using the proposed aerodynamic noise silencer of the gas flow will reduce the overall noise level in the area of operation of the noise source and improve the socio-hygienic working conditions of the staff.

Claims (1)

SILENCER OF AERODYNAMIC NOISE OF FLOW OF A GASON, comprising a body, lined with an inside of an euko-absorbing material, and a perforated pipe installed therein with a central cowling, made A in the form of two perforated cones coaxial with the pipe with a common base, which is aimed at increasing the efficiency sound attenuation, the cowl is installed in the pipe without a gap, and the coefficient of perforation of the pipe is equal to K _n > (D ^ -cP) 2d L, where D is the internal diameter of the body · - ca, m; d is the inner diameter of the pipe, m; L is the length of the perforated pipe section, m