GB2614743A

GB2614743A - Jet engine

Info

Publication number: GB2614743A
Application number: GB2200544.1A
Authority: GB
Inventors: Meredith Davies James
Original assignee: BAE Systems PLC
Current assignee: BAE Systems PLC
Priority date: 2022-01-18
Filing date: 2022-01-18
Publication date: 2023-07-19

Abstract

A gas turbine engine 100 for a vehicle is provided. The engine comprises: an intake section 101 having a compressor 102; an exhaust section having a turbine 105, the turbine being connected to the compressor via a shaft 103; and a toroidal chamber disposed between the intake section and the exhaust section having a wall 109 comprising electrical coils 112, wherein the toroidal chamber defines a vacuum for containing a plasma 110, the plasma, in use, being magnetically constrained by activation of the electrical coils. The toroidal chamber is arranged such that air drawn in by the compressor and passing over an outer surface of the wall is heated by the plasma and drives the turbine. An aircraft having the jet engine is also provided. The toroidal chamber may comprise a tokamak. The plasma may be generated by a thermonuclear reaction or nuclear fusion.

Description

JET ENGINE

FIELD

The present invention relates to a jet engine, particularly but not exclusively for use on an aircraft. The present invention also relates to an aircraft having the same.

BACKGROUND

Traditional jet engines used by aircraft notoriously generate an abundance of waste gases that contribute to global warming. There has therefore been a long felt 10 want to improve these engines to make them more efficient.

A stable controlled nuclear fusion reaction has long been a goal of scientists, due to its high power generation and harmless waste products. A number of experiments are underway around the world, with some energy now having been generated from fusion reactions. The tokamak, which uses magnetic fields to confine plasma in the shape of a torus, is considered the leading candidate for a practical device that generates energy from nuclear fusion reactions.

There is therefore a need for a fuel-efficient and sustainable jet engine design.

SUMMARY

A jet engine for a vehicle, comprising: an intake section having a compressor; an exhaust section having a turbine, the turbine being connected to the compressor via a shaft; and a toroidal chamber disposed between the intake section and the exhaust section having a wall comprising electrical coils, wherein the toroidal chamber defines a vacuum for containing a plasma, the plasma, in use, being magnetically constrained by activation of the electrical coils, wherein the toroidal chamber is arranged such that air drawn in by the compressor and passing over an outer surface of the wall is heated by the plasma and drives the turbine.

Advantageously, the jet engine provides a means to integrate a nuclear fusion reactor with a jet engine, thereby tending to increase fuel efficiency of the engine.

The shaft may be arranged to pass through an aperture lying on the central axis of the toroidal chamber.

The jet engine may comprise an electrical generator for powering the electrical coils.

The electrical generator may be driven by the shaft.

The intake section, exhaust section and toroidal chamber may be disposed in a nacelle.

According to a second aspect of the present invention, there is provided an aircraft comprising a jet engine according to any one of the preceding claims.

It will be appreciated that features described in relation to one aspect of the present disclosure can be incorporated into other aspects of the present disclosure. For example, an apparatus of the disclosure can incorporate any of the features described in this disclosure with reference to a method, and vice versa. Moreover, additional embodiments and aspects will be apparent from the following description, drawings, and claims. As can be appreciated from the foregoing and following description, each and every feature described herein, and each and every combination of two or more of such features, and each and every combination of one or more values defining a range, are included within the present disclosure provided that the features included in such a combination are not mutually inconsistent.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will now be described by way of example only with reference to the figures, in which: Figure 1 shows a cross-section through a nuclear fusion jet engine according 25 to embodiments.

DETAILED DESCRIPTION

Generally, the embodiments relate to the modification of traditional jet engine designs to accommodate a fusion reactor, thereby doing away with the need for fossil fuel injection.

The concept of nuclear fusion is not new; this disclosure relates to adapting the technology to fulfil a new purpose. Practical generation of energy using nuclear fusion is still in its infancy, but at present the main focus appears to be on harnessing the energy for large capacity requirements, such as power stations.

Most long-endurance aircraft are propelled by chemical combustion engines that require to be fuelled by many tonnes of fuel, typically hydrocarbons. Depending on the size and speed of the aircraft, endurance is measured in hours or tens of hours.

Figure 1 shows a cross-section through a turbojet engine 100 that is driven by a nuclear fusion reactor. As illustrated, the fusion reactor is a compact nuclear fusion tokomak reactor. By minimising the changes in overall layout of the nuclear jet engine 100 versus traditional jet engines, the aircraft to which they are attached will tend to require fewer modifications. In other words, the nuclear jet engine 100 may be disposed in a nacelle (i.e. an aerodynamic housing).

A traditional turbojet is a gas turbine engine that works by compressing air with an inlet 101 and a compressor 102 (axial, centrifugal, or both); mixing fuel with the compressed air; burning the mixture in a combustion chamber; and then passing the hot, high pressure air through a turbine 105 and a nozzle 106. The compressor 102 is a fan (or series of fans) driven by a shaft 103 coupled to the turbine 105, which extracts energy from the expanding gas passing through it. The turbine 105 imparts mechanical energy down the main shaft 103 of the engine, to drive the compressor 102 via a gearbox 107.

The turbojet converts internal energy in the fuel to kinetic energy in the exhaust, producing thrust. All the air ingested by the inlet 101 is passed through the compressor 102, combustion chamber, and turbine 105. The faster the compressor 102 spins, the more air is drawn through the inlet 101 and the more thrust is generated.

In the illustrated nuclear jet engine 100, the combustion chamber and fuel injectors are replaced with an air expansion chamber 104. Here, compressed air from the compressor 102 flows over the outer surface of the reactor wall 109, causing the air to be heated by convection. The heated air consequently expands towards the rear of the jet engine 100 and drives the turbine 105 as previously described.

The nuclear fusion reactor comprises a toroidal chamber 111 surrounding (i.e. encircling) the main engine shaft 103. The shaft 103 passes through the central axis of the toroidal chamber 111 (i.e. through the aperture defined at the centre of the circular plan). The chamber 111 is thermally isolated from the engine shaft 103. The chamber 111 is defined by a reactor wall 109. The reactor wall 109 may be made of any material suitable for containing the nuclear fusion reaction. The chamber 111 contains a vacuum. A ring of plasma 110 is disposed and maintained inside the chamber 111. The plasma 110 is comprised of superheated and fusing nuclear fuel, such as deuterium. It expected that a few grams of deuterium fuel would give an aircraft having the jet engine 100 an endurance measured in weeks or months. Periodically, small amounts of ionised deuterium are injected into the plasma 110 ring to sustain the fusion reaction. The ionised deuterium may be injected using magnetic ion guns that penetrate the reactor outer wall 109.

Electrical coils 112 for generating a magnetic field for magnetic containment of the plasma 110 are embedded within the reactor wall 109.

An in-line generator 108 is coupled to the main engine shaft 103. The in-line generator 108 generates electricity when driven by the shaft 103. This electricity is used to power the electrical coils 112 disposed in the fusion reactor wall 109 to create the magnetic field required to contain the plasma in the fusion reactor. The in-line generator further generates electrical power for the engine and aircraft ancillary and avionics systems (not shown in Figure 1).

The nuclear fusion reaction may be controlled, and therefore thrust may be controlled, by varying the constriction of the plasma 110. In other words, the power to the electrical coils 112 in the reactor wall 109 is adjusted to increase or decrease the strength of the magnetic field constricting the plasma 110. This reduces the probability of nuclear collision leading to fusion, and allows the plasma 110 to cool somewhat.

In one embodiment, initial start-up of the nuclear fusion jet engine 100 is achieved by external batteries driving the in-line generator 108 in reverse mode, and powering up the reactor containment field coils 112. In another embodiment, the initial start-up of the nuclear fusion jet engine 100 is achieved by a mechanical linkage driving the main engine shaft 103, thus starting the air compression process and energising the in-line generator 108.

While the described embodiment relates to modifying a turbojet engine to include a nuclear fusion reactor, it would be readily understood the augmentation is applicable to other types of jet engines, such as turboprops, turbofans, waterjets, and pulsejets.

Where, in the foregoing description, integers or elements are mentioned that have known, obvious, or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present disclosure, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the disclosure that are described as optional do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, while of possible benefit in some embodiments of the disclosure, may not be desirable, and can therefore be absent, in other embodiments.

Claims

CLAIMS1 A jet engine for a vehicle, comprising: an intake section having a compressor; an exhaust section having a turbine, the turbine being connected to the compressor via a shaft; and a toroidal chamber disposed between the intake section and the exhaust section having a wall comprising electrical coils, wherein the toroidal chamber defines a vacuum for containing a plasma, the plasma, in use, being magnetically constrained by activation of the electrical coils, wherein the toroidal chamber is arranged such that air drawn in by the compressor and passing over an outer surface of the wall is heated by the plasma and drives the turbine.
2. The jet engine according to claim 1, wherein the shaft is arranged to pass through an aperture lying on the central axis of the toroidal chamber.
3. The jet engine according to claim 1 or claim 2, comprising an electrical generator for powering the electrical coils.
4. The jet engine according to claim 3, wherein the electrical generator is driven by the shaft.
5. The jet engine according to any one of the preceding claims, wherein the intake section, exhaust section and toroidal chamber are disposed in a nacelle.
6. An aircraft comprising a jet engine according to any one of the preceding claims.