RU2491208C2 - Device to protect angine against ingress of foreign objects - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to aircraft engineering, particularly, to protective means preventing the ingress of foreign matters into aircraft engines. Proposed device comprises lower panel of relative length $$\overline{\text{l}}=\raisebox{1ex}{$\text{l}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{eqv}}$}\right.=\text{0}\text{,9}-\text{1}\text{,05}$$

and relative width $$\overline{\text{b}}=\raisebox{1ex}{$\text{b}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{eqv}}$}\right.=\text{0}\text{,9}-\text{1}\text{,1}\text{.}$$

Said panel tail is furnished with flap of relative length $$\overline{c}=c/l=\mathrm{0,2}-\mathrm{0,4.}$$

Said panel can extend for relative length $$\overline{\text{λ}}=\raisebox{1ex}{$\text{λ}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{eqv}}$}\right.$$

making 0.6-0.3 at proportional change in air intake lower edge position above airfield surface $$\overline{\text{H}}=\raisebox{1ex}{$\text{H}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{eqv}}$}\right.$$

making 0.8-1.25. Lower panel flap oscillates through the angle α_L=25°-30° relative to air intake face edge with oscillation period T= 1.0-4.0 s, where λ is panel extension, m; l is lower panel length, m; b is lower panel width, m; c is lower panel flap length, m; H is air intake lower edge position above airfield surface, m; $${\text{D}}_{\text{eqv}}=\text{2}\sqrt{\left(\text{A*B}\right)\text{/π}}$$

is equivalent diameter of air intake inlet, m; A is air intake height, m; B is air intake width, m.

EFFECT: higher efficiency of protection.

3 dwg

Description

The invention relates to the field of aviation, in particular to means of protection of power plants of aircraft from the ingress of foreign objects.

A device for protecting a power plant with jet engines from foreign objects, containing a rotary protective screen located in front of the entrance to the air intake of the engine (US patent No. 3168999, class B64D 33/02, 1965).

The known device is ineffective when the aircraft is parked due to the presence of a vortex cord at the entrance to the air intake, which facilitates the ingress of foreign objects into its tract, and the rational dimensions of the rotary protective screen and its location from the surface of the airfield are not known.

, ширина b_H нижней панели и ширина L миделевого сечения воздухозаборника выполнены в соотношении $${\overline{b}}_H=b_H/L=\mathrm{0,6}-\mathrm{0,8}$$

, а возвратно-поступательное перемещение нижней панели соответствует периоду колебаний T=0,5-2,0 с (патент RU №2131530, МПК⁷ F02C 7/05, B64D 33/02, заявлен 30.03.98).A device is known for protecting the aircraft engine from the ingress of foreign objects, comprising a movable lower panel mounted in two guides of the air intake housing, which is pivotally connected to a drive rod rigidly fixed to the air intake housing, and the latches are located in the guides. The length l _{H of the} lower panel from the front edge of the air intake and the height B of the mid-section of the air intake are made in the ratio $${\overline{l}}_H=l_H/B=0.1-\mathrm{1,0}$$

, the width b _{H of the} lower panel and the width L of the mid-section of the air intake are made in the ratio $${\overline{b}}_H=b_H/L=0.6-0.8$$

and the reciprocating movement of the lower panel corresponds to the oscillation period T = 0.5-2.0 s (patent RU No. 2131530, IPC ⁷ F02C 7/05, B64D 33/02, claimed March 30, 1998).

The disadvantages of this device include the fact that due to the reciprocating movement of the bottom panel with an oscillation period T = 0.5-2.0 s, an unsteady vortex flow forms at the inlet of the air intake, which can lead to stalling conditions at the leading edges air intake and, consequently, to reduce the stock of gas-dynamic stability of the engine and, in addition, the device is structurally complicated.

The objective of the proposed invention is to increase the efficiency of the device to protect the engine from foreign objects in all modes of operation on the ground by reducing the vortex formation rate in front of the air intake and shield protection from foreign objects entering its tract by rationally extending the bottom panel depending on the location of the air intake from the airfield’s surface and oscillatory movement of the flap of the bottom panel in a vertical plane.

и с относительной шириной нижней панели $$\overline{b}=\raisebox{1ex}{$b$}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.=\mathrm{0,9}-\mathrm{1,1}$$

осуществляется на относительную длину выдвижения нижней панели $$\overline{\lambda }=\raisebox{1ex}{$\lambda $}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.$$

, равную от 0,6 до 0,3, при пропорциональном изменении относительной высоты расположения нижней кромки воздухозаборника от поверхности аэродрома $$\overline{H}=\raisebox{1ex}{$H$}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.$$

от 0,8 до 1,25, установленную под углом α=15-20° относительно оси передней кромки воздухозаборника и совершающей колебательные движения с периодом колебаний T=1,0-4,0 с, где λ - длина выдвижения нижней панели, м; l - длина нижней панели, м; b - ширина нижней панели, м; H - высота расположения нижней кромки воздухозаборника от поверхности аэродрома, м; $$D_{ЭКВ}=2\sqrt{\left(A*B\right)/\pi }$$

- эквивалентный диаметр входа в воздухозаборник, м; A - высота воздухозаборника, м; B - ширина воздухозаборника, м.To solve this problem, in the known device for protecting the aircraft engine from foreign objects, containing a movable lower panel, which is pivotally connected to the actuator rod, rigidly mounted on the air intake housing, the extension of the lower panel with the relative length of the lower panel $$\overline{l}=\raisebox{1ex}{$l$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.=0.9-1.05$$

and with the relative width of the bottom panel $$\overline{b}=\raisebox{1ex}{$b$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.=0.9-\mathrm{1,1}$$

carried out by the relative extension length of the bottom panel $$\overline{\lambda }=\raisebox{1ex}{$\lambda $}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.$$

equal to from 0.6 to 0.3, with a proportional change in the relative height of the bottom edge of the intake from the surface of the airfield $$\overline{H}=\raisebox{1ex}{$H$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.$$

from 0.8 to 1.25, installed at an angle α = 15-20 ° relative to the axis of the front edge of the air intake and oscillating with an oscillation period T = 1.0-4.0 s, where λ is the extension length of the bottom panel, m ; l is the length of the bottom panel, m; b is the width of the bottom panel, m; H - the height of the bottom edge of the air intake from the surface of the airfield, m; $$D_{E\mathrm{TO}\mathrm{AT}}=2\sqrt{\left(A*B\right)/\pi }$$

- equivalent diameter of the entrance to the air intake, m; A - air intake height, m; B - air intake width, m.

Figure 1 shows a General view of the described protection device, side view; figure 2 is the same, front view, view B; figure 3 is the same, top view, section A-A.

The protection device includes a bottom panel 1 provided with stiffeners 2, on which the nodes 3 are located at its front and rear edges. In nodes 3, one-sided convex profiles 4 and telescopic profiles 5 are pivotally fixed, the second ends of which are pivotally mounted in nodes 6 on the body of the air intake 7 of the aircraft 8, located on the surface of the airfield 9. On the two rear telescopic profiles 5 are mounted drives 10 and the actuator rods are pivotally mounted 11, fixed rigidly to the air intake housing 7. The actuators 11 are closed by fairings 12.

, с относительной шириной нижней панели 1 $$\overline{b}=\raisebox{1ex}{$b$}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.=\mathrm{0,9}-\mathrm{1,1}$$

и способна к перемещению на относительную длину выдвижения нижней панели 1 $$\overline{\lambda }=\raisebox{1ex}{$\lambda $}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.$$

, равную от 0,6 до 0,3, при пропорциональном изменении относительной высоты расположения нижней кромки воздухозаборника 7 от поверхности аэродрома $$\overline{H}=\raisebox{1ex}{$H$}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.$$

от 0,8 до 1,25, установлена под углом α=15-20° относительно оси передней кромки воздухозаборника 7 и способна к совершению колебательных движений с периодом колебаний T=1,0-4,0 с, где λ - длина выдвижения нижней панели 1, м; l - длина нижней панели 1, м; b - ширина нижней панели 1, м; H - высота расположения нижней кромки воздухозаборника 7 от поверхности аэродрома 9, м; $$D_{ЭКВ}=2\sqrt{\left(A*B\right)/\pi }$$

- эквивалентный диаметр входа в воздухозаборник 7, м; A - высота воздухозаборника 7, м; B - ширина воздухозаборника 7, м.The bottom panel 1 is made with the relative length of the bottom panel 1 $$\overline{l}=\raisebox{1ex}{$l$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.=0.9-1.05$$

, with the relative width of the bottom panel 1 $$\overline{b}=\raisebox{1ex}{$b$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.=0.9-\mathrm{1,1}$$

and capable of moving to the relative extension length of the bottom panel 1 $$\overline{\lambda }=\raisebox{1ex}{$\lambda $}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.$$

equal to from 0.6 to 0.3, with a proportional change in the relative height of the bottom edge of the air intake 7 from the surface of the airfield $$\overline{H}=\raisebox{1ex}{$H$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.$$

from 0.8 to 1.25, installed at an angle α = 15-20 ° relative to the axis of the front edge of the air intake 7 and is capable of oscillating movements with a period of oscillation T = 1.0-4.0 s, where λ is the extension length of the lower panels 1, m; l is the length of the bottom panel 1, m; b is the width of the bottom panel 1, m; H is the height of the bottom edge of the air intake 7 from the surface of the airfield 9, m; $$D_{E\mathrm{TO}\mathrm{AT}}=2\sqrt{\left(A*B\right)/\pi }$$

- equivalent diameter of the entrance to the air intake 7, m; A - air intake height 7, m; B - air intake width 7, m.

The device protects the engine from foreign objects works as follows.

, равную от 0,6 до 0,3, при пропорциональном изменении относительной высоты расположения нижней кромки воздухозаборника 7 от поверхности аэродрома 9 $$\overline{H}=\raisebox{1ex}{$H$}\!\left/ \!\raisebox{-1ex}{$D_{ЭКВ}$}\right.$$

от 0,8 до 1,25. Например, при расположении воздухозаборника 7 на высоте $$\overline{H}=\mathrm{0,8}$$

необходимо выдвигать нижнюю панель 1 на $$\overline{\lambda }=\mathrm{0,6}$$

, при $$\overline{H}=\mathrm{0,95}$$

соответственно на $$\overline{\lambda }=\mathrm{0,5}$$

и т.д. Подаются сигналы на приводы 10, которые телескопическими профилями 5 начинают перемещать нижнюю панель 1 на угол α=15-20°, которая совершает колебательные перемещения с периодом колебаний T=1,0-4,0 с.When starting the engine in a gas stand, the automatic control system of the aircraft 9 sends signals to the drives 11 to release the protection device. The actuator rods 11 are moved forward and profiles 4 and 5 are moved along their circles forward relative to their axes in nodes 6. At the same time, the lower panel 1 in nodes 3 moves forward at an angle α = 15 ° -20 ° and the relative extension length of the lower panel one $$\overline{\lambda }=\raisebox{1ex}{$\lambda $}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.$$

equal to from 0.6 to 0.3, with a proportional change in the relative height of the bottom edge of the air intake 7 from the surface of the airfield 9 $$\overline{H}=\raisebox{1ex}{$H$}\!\left/ \!\raisebox{-1ex}{$D_{E\mathrm{TO}\mathrm{AT}}$}\right.$$

from 0.8 to 1.25. For example, when the air intake 7 is at a height $$\overline{H}=0.8$$

it is necessary to extend the bottom panel 1 on $$\overline{\lambda }=0.6$$

at $$\overline{H}=0.95$$

respectively on $$\overline{\lambda }=0.5$$

etc. Signals are sent to the actuators 10, which, with telescopic profiles 5, begin to move the lower panel 1 by an angle α = 15–20 °, which oscillates with an oscillation period T = 1.0–4.0 s.

Vortex cords are not formed on the surface of the airfield 9, since they have a low intensity, and, consequently, foreign objects do not enter the air intake path 7.

When taxiing the aircraft 8 at the aerodrome 9, the protective equipment works similarly.

In the process of take-off of the aircraft 8, signals are given to turn off the drives 10, which fix the lower panel 1 at an angle α = 15-20 °, blocking the zone of expansion of foreign objects from under the wheel of the front landing gear. At the time of separation of the wheels of the front landing gear from the surface of the airfield 9, signals are sent to turn on the drives 11, which clean the bottom panel 1 into the air intake housing 7.

The repeated inclusion of the device is carried out when landing the aircraft 8 at the moment of touching the wheel of the front landing gear with the surface of the airfield 9.

The repeated shutdown of the protection device from operation is carried out when the engine of the aircraft 8 is turned off.

The application of the present invention will improve the efficiency of the device to protect the engine from foreign objects in all modes of operation on the ground by reducing the intensity of the vortex formation in front of the air intake and shield protection from foreign objects in its path.

Claims (1)

A device for protecting the engine from foreign objects, comprising a movable lower panel that is pivotally connected to a rod of a drive rigidly mounted on the air intake housing, characterized in that the lower panel is made with a relative length of the lower panel $$\overline{\text{l}}=\raisebox{1ex}{$\text{l}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{EQ}}$}\right.=\text{0}\text{,9}-\text{one}\text{05}\text{,}$$

with the relative width of the bottom panel $$\overline{\text{b}}=\raisebox{1ex}{$\text{b}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{EQ}}$}\right.=\text{0}\text{,9}-\text{one}\text{,one}$$

has a flap in the aft part with a relative flap length of the bottom panel $$\overline{c}=c/l=0.2-\mathrm{0.4,}$$

and capable of moving to the relative extension length of the bottom panel $$\overline{\text{λ}}=\raisebox{1ex}{$\text{λ}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{EQ}}$}\right.$$

equal to from 0.6 to 0.3, with a proportional change in the relative height of the bottom edge of the intake from the surface of the airfield $$\overline{\text{H}}=\raisebox{1ex}{$\text{H}$}\!\left/ \!\raisebox{-1ex}{${\text{D}}_{\text{EQ}}$}\right.$$

from 0.8 to 1.25, installed at an angle α = 15-20 ° relative to the axis of the front edge of the air intake, while the flap of the lower panel oscillates at an angle α _З = 25-30 ° relative to the axis of the front edge of the air intake with a period of oscillation T = 1.0-4.0 s, where λ is the extension length of the bottom panel, m; l is the length of the bottom panel, m; b is the width of the bottom panel, m; c - flap length of the bottom panel, m; H - the height of the bottom edge of the air intake from the surface of the airfield, m; $${\text{D}}_{\text{EQ}}=\text{2}\sqrt{\left(\text{A}\cdot \text{B}\right)\text{/ π}}$$

- equivalent diameter of the entrance to the air intake, m; A - air intake height, m; B - air intake width, m.

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