Afterburning chamber of a gas turbine engine

 

(57) Abstract:

Usage: in the aircraft engine industry, in particular in the afterburning chambers. The essence of the invention: on the fairing performed on two sections of the perforation located at a certain protected length. When the vibration mode of combustion in the afterburner arise periodic fluctuations in pressure and gas velocity. Acoustic vibrations cause gas gas oscillations in the perforation holes 5 and 6 of the nacelle 4. The punched deflector 4 is the effect on the oscillations of a gas in the afterburner as a resonant absorber (Helmholtz resonator). Since the acoustic field inside the fairing 4 similar field in a quarter-wave resonator, the pressure fluctuations through the perforation 5 of the output section of the fairing 4 are delayed with respect to fluctuations in gas pressure in the combustion chamber at the perforation 5. The location of the perforation 6, spaced from the end of the fairing 60 - 70% of its length, you can share with the installation of sleeves 7 to hold the optimal setting of the fairing 4 a Helmholtz resonator and to provide effective damping of the acoustic vibrations in a wide range of operating modes afterburners. 3 C.p. f-ly, >Known afterburning chamber of a gas turbine engine containing installed in the housing of the front device with a ring-shaped flame stabilizer and vibration-screen TV mounted on the body (Skubachevskii, S. Aviation gas turbine engines. Design and calculation details. M., engineering, 1969, S. 445).

Known afterburning chamber of a gas turbine engine containing installed in the housing of the front device with a ring-shaped flame stabilizer located coaxially vibration absorber is made in the form of a hollow fairing with perforation at the end (U.S. patent N2934891, NCI 60-261, publ. 1960).

The objective of the invention is to intensify the damping pressure and gas velocity.

To do this in the afterburner of a gas turbine engine containing installed in the housing of the front device with a ring-shaped flame stabilizer located coaxially vibration absorber is made in the form of a hollow fairing with perforations therein, the perforations on the fairing is made in the form of two sections - one at the beginning before the stabilizer is spaced from the end of the fairing at 60-70% of its length along the axis, the second output of the fairing, and PADI perforation at the output of the fairing. In the holes of the cylindrical sleeve, with the inner wall of the fairing installed plugs, made of porous material. The perforation holes are placed along the longitudinal form of the fairing, the inside of which has a longitudinal partition forming different amounts, United holes of the perforation with a flowing part of afterburners. In the longitudinal partitions with holes with centers located on concentric circles lying in planes perpendicular to the longitudinal axis of the fairing.

New here is that the perforation on the fairing is made in the form of two sections - one at the beginning before the stabilizer is spaced from the end of the fairing at 60-70% of its length along the axis, the second output of the fairing, and the perforation at the beginning of the fairing provided with a cylindrical sleeve, and an area selected within 10-60% of the area of the perforation at the output of the fairing. In the holes of the cylindrical sleeve, with the inner wall of the fairing installed plugs, made of porous material. The perforation holes are placed along the longitudinal form of the fairing, the inside of which has a longitudinal partition forming various bylany holes with centers, located on concentric circles lying in planes perpendicular to the longitudinal axis of the fairing.

When the vibration mode of combustion in the afterburner arise periodic fluctuations in pressure and gas velocity. Acoustic vibrations cause gas gas oscillations in the holes of the perforation of the fairing. Perforated fairing effect on the oscillations of a gas in the afterburner as a resonant absorber (Helmholtz resonator). Since the acoustic field inside the fairing similar field in a quarter-wave resonator, the pressure fluctuations through the perforation of the output of the fairing is done with a delay relative to the pressure fluctuations of gas in the combustion chamber at the perforation, located in front of the stabilizer. The location of the perforation, spaced from the end of the fairing at 60-70% of its length, you can share with the installation of bushings to hold the optimal setting of the fairing as the Helmholtz resonator and to provide effective damping of the acoustic vibrations in a wide range of operating modes afterburners. Plugging of porous material, for example of the-metal in the sleeve increases the loss of vibrational energy. At times what s happening in the holes and bushings. Due to the fact that the volumes are different, you can configure the fairing on the energy absorption of acoustic oscillations of the different modes of the combustion chamber. The setting is the selection of the volumes of the cavities, the number and diameter of holes, the number, diameter and length of the sleeves. The presence of holes in the walls allows you to further expand the absorption of vibrational energy in frequencies.

In Fig.1 shows a longitudinal section afterburners;

in Fig.2 presents afterburner chamber with longitudinal septa;

in Fig.3 is a cross section of a camera with longitudinal septa.

Afterburning chamber contains installed in the front housing 1, the device 2 with the annular flame stabilizer 3. The flame stabilizer 3 is coaxially vibration absorber is made in the form of a hollow fairing 4, with perforation 5 at its output section and perforations 6 on the perimeter in the beginning before the flame stabilizer 3. The perforation 6 in the beginning of the fairing has a cylindrical sleeve 7 and is made before the flame stabilizer 3 at a distance from the end of the fairing equal to 60-70% of its length on its axis. The area of the perforation 6 is selected in the range 10-60% of the area of the perforation 5 of the output plot. In ATVs porous material. The perforation holes 5 and 6 are placed along the longitudinal forming fairing 4, within which is installed a longitudinal walls 9 forming different volume 10, United perforation holes 5 and 6 with a flowing part of afterburners. In a longitudinal partition 9 holes 11 with centers located on concentric circles lying in planes perpendicular to the longitudinal axis of the fairing.

When working afterburners is the burnup of the fuel-air mixture for the flame stabilizer 3. Upon receipt of the mode of vibration of the combustion in the afterburner arise periodic fluctuations in pressure and gas velocity. Acoustic vibrations cause gas gas oscillations in the perforation holes 5 and 6 of the nacelle 4. The punched deflector 4 is the effect on the oscillations of a gas in the afterburner as a resonant absorber (Helmholtz resonator). Since the acoustic field inside the fairing 4 similar field in a quarter-wave resonator, the pressure fluctuations through the perforation 5 of the output section of the fairing 4 are delayed with respect to fluctuations in gas pressure in the combustion chamber at the perforation 6. The location of the perforation 6, separated from Coca fairing 4 a Helmholtz resonator and to provide effective damping of the acoustic vibrations in a wide range of operating modes afterburners. Note: installing filler brackets 8 of porous material, for example of the-metal in the sleeve 7 increases the loss of vibrational energy. With the development in the afterburner having a longitudinal partition 9, the acoustic waves and the dissipation of the oscillation energy is in the holes 5 and the sleeve 7. Due to the fact that the volume of 10 different, you can configure the fairing 4 on the energy absorption of acoustic oscillations of the different modes of the combustion chamber. The setting is the selection of the volumes of the cavities 10, the number and diameter of holes 5, the number, diameter and length of the sleeves 7. The presence of the holes 11 in the walls allows you to further expand the energy absorption of the oscillation frequency.

1. Afterburning chamber of a gas turbine engine containing within the enclosure of the front device with a ring-shaped flame stabilizer located coaxially vibration absorber is made in the form of a hollow fairing with perforations therein, characterized in that the perforation on the fairing is made in the form of two sections - one at the beginning before the stabilizer is spaced from the end of the fairing 60 - 70% of its length along the axis, the second output of the fairing, and the perforation at the beginning of the fairing provided with a cylindrical whom and under item 1, characterized in that the holes of the cylindrical sleeve, with the inner wall of the fairing installed plugs, made of porous material.

3. Luggage under item 1, characterized in that the perforation holes placed along the longitudinal form of the fairing, the inside of which has a longitudinal partition forming different amounts, United holes of the perforation with a flowing part of the afterburner chamber.

4. The camera on the PP.1 and 3, characterized in that the longitudinal partitions with holes with centers located on concentric circles lying in planes perpendicular to the longitudinal axis of the fairing.

 

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