SU831201A1 - Method of emitting tone sound to environment - Google Patents

Description

(54) METHOD OF RADIATION OF A VOID SOUND INTO THE ENVIRONMENT

I

The invention relates to the production of vibrations and may find application in industry, where studies are conducted on the effects of noise on mechanisms, devices and organisms.

A known method of radiating sound into the surrounding medium is based on passing a gas stream under supercritical pressure through a critical section and subsequent modulation after first reducing its velocity 1.

The disadvantage of this method is the non-effusional radiation efficiency.

The closest to the proposed technical dryness and the achieved result is a method of emitting tonal sound into the environment, based on passing a gas stream under supercritical pressure through the critical section followed by its modulation and changing the area of the critical section 2.

The disadvantage of this method is the impossibility of a smooth change in the frequency of the emitted tonal sound.

The purpose of the invention is to increase the efficiency of adjusting the frequency of the tone of the sound.

This goal is achieved in that the flow deceleration pressure is maintained in the range of 2.0-4.0 pressure in the environment, and the critical section area is changed in the range from 0.15 to 0.75 flow cross section.

A method of emitting tonal sound into the environment is implemented as follows.

The gas jet is formed by passing a supersonic nozzle through the critical section, from where it expires in the mode of pressure deceleration of a flow of 2.0-4.0 in the environment with a non-designation equal to one (in the non-design mode). Along this, a downstream structure forms a periodic structure, the interaction of which with the environment causes acoustic disturbances that propagate downstream of the jet. Due to the instability of the flow boundaries, these disturbances are amplified, as a result of which acoustic waves are emitted into the environment, which, propagating towards the critical section, act on Kiipeiii) cT () ii ii iU)) T iioHU.ieiiiie

THE ASSISTANCE i: i BOTTOM CHC | 1 BO;, M V IHCli AND ii.

 rui; i, ie / Kaiiieii (juKinpoiiKc acoustic b.), ii i-iacTviiacT |) mode of wild game from / iyiciiiiH. iifii which is a thistle of jets .i), iirsu 5 ;. st11u hesitates to fluctuate.

, liH pl.N) | h; and ef (|) ectp1 1K) 1 about changing the frequency-1 | 1: 3; | part1O1) sound is necessary ii.iaiV but MtMiirri, the size of the critical 1H) cross-section of the sop, ia. Sagavl 5 in D1 a11 braking zone of the sock 2.0--4.), lemn in the environment. The 11mm turbine structure of the jet changes the SION geometrical dimensions, and thus () M, due to the modulation of the jet and the frequency of the geological jetting of the original and icer k.k.

, 1) ;: iifiej stub, .iaraeMoio is able to sound from the tonal | 101X) sound into the surrounding environment 11 (1Store1, 31Ach1; those; 1iio to increase the accuracy and (k-t1) settings of the frequency, and to increase gatov.

Claims (2)

1. USSR author's certificate .N0 591238, cl. B 06 B 1/20, 1978. 2. Tolstosheev MN and, Efremov NL. Droppings of noise reduction of supersonic off-design jets. - Sat. “The noise of jet engines. CIAM, 1975 (prototype).