RU2573698C2 - High-speed rotorcraft - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: claimed craft comprises the rotor, wing, fuselage, aircraft-type tail unit and aircraft-helicopter-type control system. The autorotating rotor with the rigid attachment of blades can be converted to the wing. Turbofans incorporate reverse-deviator devices.

EFFECT: better takeoff-and-landing performances.

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Description

The present invention relates to the field of aviation, in particular to helicopter engineering, and is aimed at creating a helicopter planes - a rotorcraft with an autorotating rotor, take-off and landing without take-off run, increased cruising speed, aerodynamic quality and flight range compared to helicopter, rotorcraft and a known rotorcraft [1].

In terms of the set of distinguishing features, the closest is the technical solution of a rotorcraft with an autorotating rotor and wing [1].

In a known technical solution, a rotary-wing aircraft has an autorotating rotor and a wing, turboprop engines with variable pitch propellers, a fuselage, an aircraft tail unit and a helicopter-aircraft control system. The main rotor is designed to provide take-off and landing without an take-off run, and the wing is designed to provide maximum unloading of the main rotor at high flight speeds.

At the same time, a rotating rotor at a cruising flight speed has a significantly lower aerodynamic quality compared to the aerodynamic quality of the wing. In addition, the rotation of the rotor requires the irrational expenditure of energy of the incoming air flow and engine power. As a result of this, the aerodynamic quality of this rotary rotor system is less than the aerodynamic quality of the wing.

Therefore, to obtain the maximum aerodynamic quality of this system, it is necessary to stop the rotation of the rotor in flight, converting it into a wing with a minimum value of the angles of installation of the blades to minimize the lifting force and aerodynamic drag created by them. The most suitable for the implementation of such a conversion is an autorotating rotor with a rigid attachment of the blades to the sleeve.

It is known [2] that the engine power per unit of take-off weight of vertically take-off aircraft is: for helicopters 0.25 ... 0.3 hp / kgf, for jet aircraft 3 ... 4 hp / kgf (equivalent power). Consequently, there is no alternative to the rotor in terms of the minimum cost of engine power per unit of take-off weight of the aircraft for vertical take-off and landing.

Therefore, for a helicopter it is advisable to take advantage of the positive effect that a combination of a rotor - lift-propulsion engines can give to increase its take-off and landing characteristics compared to the known rotary-wing aircraft [1]. For this, turboprop engines with variable pitch traction screws must be replaced by turbofan engines equipped with reversible-deviator devices [3].

Reversible devices of turbofan engines are used to brake the device and reduce its landing speed, similar to reversing the propellers of a variable pitch of turboprop engines on a well-known rotorcraft. Deviators - rotary nozzles of turbofan engines are used to deflect them to the surface of the platform at a given angle on take-off and landing in order to create a vertical component of the thrust that complements the thrust of the rotor.

The task to which the proposed technical solution is directed is to create a helicopter with an autorun convertible into a wing (two, three, four-bladed) rotor to minimize the aerodynamic drag of the rotor-wing system in order to achieve higher values of cruising speed, aerodynamic quality and flight range in comparison with a helicopter, rotorcraft and a known rotorcraft [1]. In addition, a helicopter in comparison with this rotary-wing aircraft should have higher takeoff and landing characteristics.

The technical result is ensured by the fact that in a known rotary-wing aircraft containing an autorotating rotor, turboprop engines with variable speed propellers, a wing, a fuselage, an airplane type tail, an airplane-helicopter control system, an autorotating rotor with a rigid mount of the blades are made convertible in the wing, turbofan engines are made with reversible-deviator devices.

The technical solution of the invention is illustrated by the drawing of FIG. 1. In FIG. 1 schematically shows a helicopter in flight with a rotating three-blade (for example) rotor. The hovercraft contains an autorotating rotor with rigid fastening of the blades 1, wing 2, turbofan engines 3, fuselage 4, tail unit 5. In FIG. 2 helicopter is presented in flight with a rotor converted to a wing.

The flight of a helicopter is as follows.

Before take-off of the helicopter without take-off, as on the well-known rotorcraft, at the start they carry out the spin-up of the rotor rotor 1 to a given rotation speed in order to acquire the necessary kinetic energy reserve.

After that, using the known control system for increasing the total pitch and the thrust of the rotor 1, the apparatus is vertically lifted until the chassis wheels come off the platform surface. Then, almost simultaneously, the control levers of the turbofan engines (ORE) are moved to the take-off position and the vehicle is accelerated to the desired speed and altitude values at take-off.

All recommendations for the implementation of this take-off method [4] are applicable in full if obstacles in the take-off direction do not exceed the normalized values in height. If there are higher obstacles, while turning the throttle to the take-off position, the rotary nozzles of the turbofan engines 3 are deflected towards the take-off area by a predetermined angle in order to create a vertical thrust component that complements the thrust of the main rotor to realize a steeper trajectory of the helicopter during take-off, comparable to the trajectory of movement helicopter.

In horizontal flight, with increasing speed, the lift of the wing 2 increases, unloading the rotor. At a given speed, the rotational speed of the rotor 1 is reduced until it is completely stopped. To do this, establish such a common pitch of the rotor at which the angles of inflow of the air flow to the sections of the advancing blades and the projection of their aerodynamic forces on the direction of movement are minimal.

When the main rotor 1 reaches the minimum speed and the specified azimuthal position of its blades, the main rotor brake is applied for its final braking and fixing. This brake is also used to stop the rotation of the rotor and fix it in the parking lot after the flight is completed. Known designs of such brakes and their control systems for stopping the rotation of the rotor and fixing it in the parking lot after completion of the flight have found application, for example, in mass-produced helicopters.

As a result of this transformation, two blades of a three-bladed main rotor 1, located in front of its axis of rotation symmetrically with respect to the longitudinal axis of the fuselage, become consoles of the swept wing type. The third rotor blade is located behind the axis of its rotation above the fuselage. After that, by a common step, set the values of the angles of installation of the blades to minimize the lifting force created by them and their aerodynamic drag at high flight speeds.

It is known that the aerodynamic profile drag of a wing consists of friction drag and shape (pressure) [5]. A distinctive feature of the swept wing of a helicopter is that the left blade of the stopped main rotor flows around the air flow in front and the right blade in the back.

At air flow rates with a Mach number of not more than 0.7, the friction resistance of the profiles of the blades - wing consoles will be the same. The resistance of the handicap profiles of the left blade due to the different direction of the incoming air flow will be slightly different from the shape resistance of the profiles of the right blade. However, the shape resistance of profiles with a small relative thickness is significantly less than the friction resistance of these profiles.

Therefore, the aerodynamic profile resistance of the left and right blades of a stopped rotor in flight will be almost the same. This is what allows us to abandon the complicated method of turning the right blade 180 ° during braking of the rotor in order to achieve its full identity with the left blade with respect to the incoming air flow.

All this together allows you to realize higher values of cruising speed, aerodynamic quality and flight range on a helicopter compared with a helicopter, rotorcraft and a known rotorcraft [1].

Before entering the helicopter landing in horizontal flight at a given speed, the rotor brake is turned off, the necessary general step is set for the rotor to spin up by the incoming air flow to the required speed. In order to accelerate the promotion of the rotor, if necessary, use the system of its promotion at the start before takeoff.

To perform a helicopter landing without mileage, a predetermined speed, a predetermined total pitch of the autorotating rotor 1 are set on the planning glide path to ensure the maximum possible rotation frequency and the required kinetic energy reserve. Then, at a predetermined height relative to the surface of the landing pad, reversible devices of turbofan engines 3 are turned on to brake the apparatus and reduce the landing speed. After that, before the end of braking, the overall pitch and thrust of the rotor 1 are increased to reduce the landing speed of the apparatus up to zero by the time the wheels of the chassis touch the surface of the platform.

All recommendations for the implementation of this landing method [6] are acceptable on a helicopter in full. If it is necessary to land on a site of limited size, after braking the device and turning off the reversing devices of the turbofan engines 3, the rotary nozzles of the engines are deflected to the surface of the platform by a predetermined angle to create a vertical component of the thrust in addition to the thrust of the main rotor 1. This allows short-term hovering a helicopter before landing like a helicopter.

The analysis of the prior art by the applicant showed that the set of essential features of the claimed technical solution is new and industrially acceptable to achieve the specified technical result and meets the patentability condition of the invention.

Information sources

1. Patent RU 130951 U1, IPC ВСС 27/22, publ. 08/10/2013

2. Mil M.L., Nekrasov A.V. and other helicopters. Calculation and design. Aerodynamics. Publishing House "Engineering", Moscow, 1966 (p. 26).

3. Maksimov Η.Α., Sekistov Β.Α. “Aircraft and Helicopter Engines,” Military Publishing House of the USSR Ministry of Defense, Moscow, 1977 (p. 197-202).

4. Patent RU 2514012 C1, IPC ВСС 27/02, publ. 02/25/2014

5. Svishchev G.P. Aviation, encyclopedia. Scientific publishing house "Big Russian Encyclopedia", TsAGI, Moscow, 1994 (p. 527, 528).

6. Patent RU 2506203 C1, IPC ВСС 27/02, publ. 02/10/2014

Claims (1)

A rotary-wing aircraft containing a rotor, a wing, a fuselage, an aircraft-type tail unit, an aircraft-helicopter control system, characterized in that the autorotating rotor with a rigid blade mount is made convertible into a wing, turbofan type engines are made with reversible-deviator devices.

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