This application is the national phase under 35 U.S.C. §371 of PCT/SE2009/050424 filed 23 Apr. 2009.
The invention relates to an arrangement for storing and launching payloads, in particular an arrangement for storing and launching counter-measures, such as flares and chaff.
Arrangements for storing and launching payloads, such as counter-measures, being designed to be mounted on vehicles, such as an aircraft of the aeroplane type, are previously known. According to the state of the art, such arrangements comprise an elongate body provided with at least one launch opening. Such arrangements are mounted with the longitudinal direction of the elongate body essentially coinciding with the flight direction of the aircraft. The counter-measures being connected to a firing control unit for feeding firing signals to the counter-measures. The counter-measures can consist of passive means, such as chaff foil, but can also consist of flares, for example IR flares, or other active measures.
One problem is that unfavourable acoustic phenomenon, such as extremely high air induced noise and vibration levels, are generated due to the openings of the compartments, after firing of the counter-measures. The relative wind, due to the speed of the vehicle, interacts with the open, remaining cartridges of the compartments in which the counter-measures have been accommodated. The open compartments can act as barrels which oscillate at its inherent frequency. The acoustic phenomenon could be localised by target-seeking missiles and may also cause damage on the equipment, such as electric components, due to strong vibrations created.
The longitudinal extension and the number of openings of the compartments in the elongated body can be rather large. The protective effect of previously known vortex generators arranged in front of the compartments decreases with increasing length of the openings of the compartments.
Another problem is that previously known sound absorbing means, in arrangements according to the state of the art, generates turbulent flows that are difficult to control and results in high energy losses. The previously known sound absorbing means also contributes to an increased extension of the design of the arrangement in the longitudinal extension of the vehicle.
Yet another problem with the arrangements according to the prior art is the sensitivity for influence of the air flow that is affected by the speed and position of the vehicle.
An example of a previously known arrangement described as a dispenser which is used for launching counter-measures and provided with compartments, is described in document WO-A1-0059782. An elongated body of the dispenser is provided with fixed means, described as a spoiler, in front of the compartments for acting on the air stream and for creating a low dynamic pressure across the compartment openings.
From document U.S. Pat. No. 4,696,442 it is known to provide the exterior surface of an aircraft with a pair of vortex generators arranged right in front of an inlet opening in order to increase the mass airflow into the inlet.
One object of the present invention is to at least partially eliminate the drawbacks associated with the solutions known in the prior art.
Another object is to minimise the occurrence of acoustic phenomenon which are caused by the openings in compartments which have been emptied of payloads, such as counter-measures.
Yet another object is to prevent the occurrence of vibration disturbances which are primarily caused by inherent oscillations in compartments which have been emptied of payloads.
A further object is to provide an arrangement that is independent of the longitudinal extension and the number of openings of the compartments in the elongated body. Moreover, it is an object with the present invention to provide a solution that has a compact design, that not contributes to high energy losses, and that is insensitive to the position and speed of the vehicle.
Thus, air deflecting means are arranged on the side of the compartments, directing the air flow obliquely and crosswise over the openings, such that a stable laminar flow is provided over the openings. A layer of air is created that covers the openings. The aeroacoustic phenomenon and vibration disturbances are decreased or essentially eliminated.
By generating a laminar air flow over and across the openings, creating an air covering layer, a favourable low drag contribution is obtained. The creation of an air covering layer over and across the compartment openings has been shown to effectively counteract oscillations caused by the inherent frequencies of the compartments, since the laminar air flow near the openings of the compartments means low drag contribution and low energy.
By the arrangement of the air deflecting means according to the present invention, a compact design is reached, and which works independently of the longitudinal extension of the openings and the position of the vehicle, such as an attack or sideslip angle of the aircraft.
According to an embodiment, the elongate body is provided with at least two deflection means arranged in a row in the longitudinal direction of the elongate body. According to yet an embodiment, the elongated body is provided with at least two deflection means, arranged in parallel and in pairs, one on each side of one opening. At least one deflection means can be arranged adjacent and obliquely in front of the most forward opening. The elongated body can be provided with at least one deflection means along the longitudinal side adjacent each opening.
When at least two deflection means are arranged in parallel and in pairs, one on each side of one opening, first deflection means are arranged along one side of the launch opening, for redirecting an air flow to create a first air covering layer over and across the openings of the compartments. Then, second deflection means are arranged along another opposite side of the launch opening, for redirecting an air flow to create a second air covering layer over and across the openings.
The deflection means can be made movable. However, according to a preferred embodiment, the deflection means are fixed to the elongated body. In a further embodiment, a surface area of the deflection means, which surface area is facing the air flow in the direction of motion, can be altered. The rear side of the deflection means can be provided with a protrusion. An air redirecting surface of the deflection means is preferably arranged above the surface of the dispenser.
Further embodiments and advantages are described below with reference to the drawings.
The invention will be described in greater detail below by way of illustration of embodiments and with reference to the attached drawings, in which:
An aeroplane 1 shown in
The dispenser 2 is described in more detail with reference to
The elongate body 8 is provided with deflection means. According to the embodiment shown in
The deflection means 15.1, 15.2 . . . 15.n, respectively, hereinafter also denoted as air deflector(s) can be in the form of a nozzle, a wing, a channel, a fin or the similar. According to an embodiment, a respective deflector can be designed to be non-rigid, such that it could collapse when subjected to a high air drag. Each deflector 15.1, 15.2 . . . 15.n may also be designed to be foldable and unfoldable. Hence, the deflector(s) 15.1, 15.2 . . . 15.n can be movable, such that they can be retracted, unfolded, tilted and/or displaced in any direction, by active control means or automatically due to the air drag.
According to another preferred embodiment, each air deflector 15.1, 15.2 . . . 15.n is fixed to the elongated body 8, with a fixed inclined angle towards the flight direction F.
In
As illustrated in
According to the above mentioned embodiments in
A first deflector 15.1 can be arranged adjacent and obliquely in front of the most forward opening 12.1, on one or on each side of the opening 12.1.
According to another embodiment, the elongated body 8 is provided with at least a pair of deflectors 15.1, 15.2, . . . 15.n adjacent each opening 12.1, 12.2, . . . , 12.n. In that respect, the deflectors are arranged such that one air flow that is directed by the first deflectors 15.1, respectively, cross-wise over and across openings 12.1, 12.2, . . . , 12.n of the compartments 11.1, 11.2, . . . , 11.n, is not directed directly towards another deflector too not interfere with second deflectors 15.2, of the compartments 11.1, 11.2, . . . , 11.n.
The deflectors 15.1, 15.2, . . . 15.n are preferably arranged such that the air covering layer 16 is created slightly above the compartments 11.1, 11.2, . . . , 11.n, suitably above the surface S of the elongate body 8, in order to eliminate any possible occurrence of a turbulent flow at the surface. This can be accomplished by arranging an air redirecting surface 18 of the deflector above the surface of the dispenser, as evident from
The surface area, the width and the vertical extension, of each deflector facing the flight direction, are designed in order to reach the desired airflow boundary layer thickness over the compartments. The deflectors 15.1, 15.2, . . . 15.n may be designed with various shapes such as convex, inclined surfaces, or the like.
As mentioned above, a redirected air flow should not interfere with another redirected airflow, since energy is lost due to a decreased air speed and any air covering layer could not be created, or alternatively would be poor. A redirected air flow from one longitudinal side should not interfere with a redirected air flow from the opposite longitudinal side. According to one embodiment of the present invention as evident from
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/SE2009/050424 | 4/23/2009 | WO | 00 | 1/12/2012 |
Publishing Document | Publishing Date | Country | Kind |
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WO2010/123423 | 10/28/2010 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3430533 | Kifor et al. | Mar 1969 | A |
3808941 | Biggs | May 1974 | A |
4417709 | Fehrm | Nov 1983 | A |
4679483 | Wrana | Jul 1987 | A |
H324 | Rubin | Sep 1987 | H |
4696442 | Mazzitelli | Sep 1987 | A |
5198609 | Gillman | Mar 1993 | A |
5340054 | Smith et al. | Aug 1994 | A |
5461960 | Marks | Oct 1995 | A |
5699981 | McGrath et al. | Dec 1997 | A |
6098925 | Burdsall, II et al. | Aug 2000 | A |
6619178 | Fransson et al. | Sep 2003 | B1 |
7373886 | Zatterqvist et al. | May 2008 | B2 |
7520467 | Gioffre et al. | Apr 2009 | B2 |
7600477 | Zatterqvist | Oct 2009 | B2 |
7614334 | Bellino et al. | Nov 2009 | B2 |
7840124 | Olwin | Nov 2010 | B2 |
7866246 | Bellino et al. | Jan 2011 | B2 |
20040104309 | Segota et al. | Jun 2004 | A1 |
20040200381 | Zatterqvist | Oct 2004 | A1 |
20040200382 | Zatterqvist et al. | Oct 2004 | A1 |
20050204910 | Padan | Sep 2005 | A1 |
20090084253 | Bellino et al. | Apr 2009 | A1 |
20090084254 | Bellino et al. | Apr 2009 | A1 |
20120125183 | Zatterqvist | May 2012 | A1 |
Number | Date | Country |
---|---|---|
1950522 | Jul 2008 | EP |
2665875 | Feb 1992 | FR |
191424021 | Jan 1915 | GB |
WO-0059782 | Oct 2000 | WO |
Entry |
---|
PCT/ISA/210—International Search Report—Dec. 11, 2009. |
PCT/ISA/237—Written Opinion of the International Searching Authority—Dec. 11, 2009. |
PCT/IPEA/408—Written Opinion of the International Preliminary Examining Authority—Mar. 31, 2011. |
PCT/IPEA/409—International Preliminary Report on Patentability—Jul. 26, 2011. |
Number | Date | Country | |
---|---|---|---|
20120125183 A1 | May 2012 | US |