RU2259307C2 - Device for transportation of cargoes on external store of helicopter - Google Patents

Abstract

FIELD: transportation of cargoes on external store of helicopter.

SUBSTANCE: container in form of parallelepiped is located on common bed frame. Adjacent faces of container which are frontal ones or lateral relative to incoming flow are provided with air passages for reduction of pressure difference at adjacent faces.

EFFECT: improved flight characteristics of helicopter due to increased range of transportation speeds.

1 dwg

Description

The invention relates to aircraft, in particular to devices for transporting goods on the external suspension of helicopters, and can be used in their designs.

Known devices for transporting goods on an external flexible cable suspension of a helicopter, which is a container in the form of a parallelepiped (Fundamentals of the design and technical operation of single-rotor helicopters, edited by A.M. Volodko. - M .: Voenizdat, 1986, p. 97).

The disadvantage of these devices when transporting them by helicopter is significant circular vibrations of various shapes and amplitudes of the transported cargo located on the external flexible cable suspension of the helicopter due to unbalanced aerodynamic forces caused by flow separation from the side faces of the parallelepiped-shaped container surface. For this reason, the maximum speed of cargo transportation by helicopter in a given flight configuration is limited.

Known devices for transporting goods by helicopter on an external flexible cable suspension, equipped with additional devices for stabilizing the load in the air stream, structurally made in the form of fairings, mounted on the side faces of an arbitrary shape container in such a way as to ensure smooth and continuous flow around the front, relative to the oncoming air flow, parts of the transported container (Civil Aviation Magazine, No. 7, 1990, p.26, prototype). This effect partially eliminates the occurrence of unbalanced unsteady aerodynamic forces that cause load vibrations.

The disadvantages of these stabilizing devices are the increase in aerodynamic drag of the container due to the increase in the surface washed by air due to the stabilization devices, as well as the increase in labor costs due to the work associated with attaching these devices to the container in preparation for cargo transportation. In addition, these devices are not universal and do not provide effective stabilization of any cargo.

The objective of the present invention is to improve the flight performance of a helicopter when flying with cargo on an external sling by expanding the range of transportation speeds. This is achieved by developing a device for transporting goods on the external cable suspension of the helicopter, which is a container in the shape of a parallelepiped, which helps to prevent a significant degree of buildup of cargo with an acceptable value of increment of drag and, therefore, increase the permissible speed of cargo transportation.

To solve this problem, the device for transporting goods on the external cable suspension of a helicopter, which is a container in the shape of a parallelepiped, adjacent (angular) faces of the container, which are frontal or lateral with respect to the incoming air flow, are interconnected by passable channels for air. The presence of channels allows you to reduce or eliminate the air pressure drop at adjacent faces in the places of the corners (edges) of their intersection. Reducing the pressure drop reduces the likelihood of flow breaks from the ribs forming the container surface. In the event of a separation, the presence of channels significantly reduces its intensity (again, due to a decrease in pressure drops). It is the presence of flow breaks, developed stall zones, which leads to the unsteady, periodic, pulsating nature of the change in aerodynamic loads acting on the container. In addition, it is the presence of flow breaks that leads to the parallelepiped-shaped containers being prone to self-oscillations under the influence of the oncoming flow.

The drawing shows a diagram of the device.

The device comprises a parallelepiped-shaped container 1 placed on a common frame 2, so that the front or side faces of the external parallelepiped-shaped container, surface 3 are interconnected by communicating channels 4, 5, 6, 7, which are passable for air. The container in the case under consideration, it is attached to the helicopter by means of an external cable suspension so that the lower (according to the drawing) end parts of the cables 8 diverging downward are attached to the corners of the upper faces of the container surface 3, and the cargo cable 9 was attached to the helicopter cargo suspension system located on the fuselage.

The specified device operates as follows.

When flying a helicopter with cargo on an external cable suspension, an incoming air flow passing through communicating angular channels 4, 5, 6, 7, reduces the pressure drop across adjacent container faces. Due to the free passage of air between adjacent faces of the parallelepiped (for example, 3), the pressure drop across these faces decreases, which leads to a general decrease in the forces and moments acting on the load. The decrease in forces and moments in turn leads to a decrease in the amplitude of oscillations of the container 1.

The shape of the corner channels 4, 5, 6, 7 may vary depending on the weight, shape and size of the container.

Claims (1)

A device for transporting goods on the external cable suspension of a helicopter, which is a container in the shape of a parallelepiped, placed on a common bed, characterized in that in adjacent faces of the container, which are frontal or lateral with respect to the incoming air flow, passable air channels, allowing to reduce the air pressure drop at adjacent faces.