This application claims priority to United Kingdom Patent Application GB 2304778.0, filed Mar. 31, 2023, the entire contents of which is hereby incorporated by reference.
The present invention relates to an aircraft, a kit of parts, and a method of transferring fluids to and/or from an aircraft.
Jet fuels are the most common aircraft fuels. There are recent advances that supplement these conventional jet fuels with similar biofuels, such as sustainable aviation fuel (SAF). There are also ambitions to use other fuels such as ammonia and hydrogen, with combinations of these fuels expected to have respective advantages in different flight phases. Historical examples of dual-fuel aircraft have included the B57 Canberra as part of NACA's project Bee, in which kerosene-based fuel and hydrogen fuel were used alternately during flight.
In many cases, the employment of dual-fuel aircraft will require substantial changes to existing designs and procedures to account for fuels that may not be compatible in terms of storage or combustion.
A first aspect of the invention provides an aircraft comprising a port over which a first connector is mounted for connecting to a second, complementary connector to transfer fluid to and/or from the aircraft, the first connector including a first fluid path extending from the port towards an aircraft fluid tank and a second, different, fluid path extending from the port towards an aircraft fluid tank.
A port is defined as an opening in the side of the aircraft.
With this arrangement, multiple fluids can be transferred to and/or from the aircraft with only a single connector pair. This reduces the number of couplings needed for, e.g., refuelling a multi-fuel aircraft.
Optionally, the cross-section of the first fluid path is different to the cross-section of the second fluid path.
Optionally, the first fluid path is concentric with the second fluid path.
Optionally, the first fluid path is defined by a first conduit of the first connector, and the second fluid path is defined by a second conduit of the first connector, wherein the first conduit extends through an outer wall of the second conduit.
Optionally, the first connector comprises an alignment pin or an alignment port for mating with a corresponding alignment port or alignment pin of a second connector so as to align the connectors.
Optionally, the first fluid path extends to a first aircraft fluid tank and the second fluid path extends to a second aircraft fluid tank.
Optionally, the first and/or second aircraft fluid tank is an aircraft fuel tank.
Optionally, the first fluid path and the second fluid path extend to a common fluid tank.
Optionally, the first connector includes a third fluid path extending to an aircraft fluid tank. The third fluid path may extend to a third fuel tank, or the third fluid path may extend to the same fuel tank as one of the first and second fluid paths.
A further aspect of the invention provides a kit of parts comprising the aircraft of any preceding claim and a second, complementary connector configured to releasably connect to the first connector to form a connection, the second connector including a first fluid path that upon connection to the first connector extends from the first fluid path of the first connector towards an external fluid tank, and a second fluid path that upon connection to the first connector extends from the second fluid path of the first connector towards an external fluid tank. The first and second fluid paths may extend to a common fluid tank or separate fluid tanks.
Optionally, the first connector and the second connector are configured such that: the first fluid path of the first connector is unable to form a fluidically sealed path with the second fluid path of the second connector, and the second fluid path of the first connector is unable to form a fluidically sealed path with the first fluid path of the second connector.
This arrangement ensures the connection is always formed correctly, with no risk of cross-flow between the respective fluid paths.
Optionally, the second connector is a male connector and the first connector is a female connector configured to receive the second connector.
Optionally, the connection includes a locking mechanism configured to releasably fix the second connector relative to the first connector.
A further aspect of the invention provides a method of transferring fluids to and/or from an aircraft, comprising: providing an aircraft having a port over which is mounted a first connector, the first connector connected to a second connector to form a connection, the first connector including a first fluid path extending from the port towards an aircraft fluid tank and a second, different, fluid path extending from the port towards an aircraft fluid tank; transferring a first fluid through the first fluid path to transfer the first fluid to or from the aircraft; and transferring a second fluid through the second fluid path to transfer the second fluid to or from the aircraft. The first fluid may be different to the second fluid.
The method optionally comprises transferring the first fluid through the first fluid path to or from a first aircraft fuel tank, and transferring the second fluid through the second fluid path to or from a second aircraft fuel tank.
The method optionally comprises transferring the first fluid through the first fluid path to or from an aircraft fuel tank, and transferring the second fluid through the second fluid path to or from the aircraft fuel tank.
Optionally, wherein the first fluid is one of a first aviation fuel, a second aviation fuel, fuel additives, oxygen-depleted air, a tracer gas, hydraulic fluid, engine oil, or water, and wherein the second fluid is a different one of a first aviation fuel, a second aviation fuel, fuel additives, oxygen depleted air, a tracer gas, hydraulic fluid, engine oil, or water.
Optionally, wherein the first aviation fuel and second aviation fuels comprise one of a jet fuel, sustainable aviation fuel, ammonia, liquid hydrogen, and gaseous hydrogen.
Optionally, the method comprises: transferring water through the first fluid path towards an aircraft water tank, and transferring waste through the second fluid path from an aircraft waste tank.
Embodiments of the invention will now be described with reference to the accompanying drawings, in which:
The aircraft 1 includes one or more fuel tanks 10a, 10b into which a quantity of fuel is transferred sufficient to complete the next flight, such as shown in
The refuelling panel 11 and refuelling port 12 are located adjacent an access hatch 14 of the aircraft 1. The hatch 14 may form an outer aerodynamic surface of the aircraft 1, with the hatch 14 shown in an open position in
The refuelling port 12 is located adjacent a lower cover of the aircraft wing 2, however it will be appreciated that the refuelling port 12 (and access hatch 14 when applicable) may be located in any suitable location on the wings 2, 3, fuselage 4, or on a fairing (not shown).
In the closed position, the hatch 14 covers the refuelling port 12, such that the refuelling port 12 has a central axis that is substantially normal to the outer aerodynamic surface of the aircraft 1. The hatch 14 provides convenient external access to the refuelling port 12 so that fuel can be transferred to the fuel tank 10 via a refuel hose 15.
There is a desire to minimise the time required to refuel aircraft 1 due to refuelling being a significant contributor to the time required for aircraft 1 to remain grounded between flights. This desire is only expected to increase if aircraft move towards the use of multiple fuels.
The first connector 20 is typically a female connection configured to receive a male second connector 30, such that the second connector 30 is inserted into an aperture of the first connector 20. In this case, the first fluid paths 21, 31 may have different diameters, and similarly the second fluid paths 22, 32 may have different diameters, such that there is a step change in the cross-section of the channels across the connection (such as shown in
The first connector 20 and second connector 30 each define first and second fluid paths therethrough. In particular, the first connector 20 includes a first fluid path 21 extending towards a first fuel tank 10a and a second fluid path 22 extending towards a second fuel tank 10b, and the second connector 30 includes a first fluid path 31 extending towards a first external fuel tank 50a and a second fluid path 32 extending towards a second external fuel tank 50b. An example of this arrangement is shown schematically in
In this example, the first fluid paths 21, 31 are each defined by a respective first conduit 24a, 34a and the second fluid paths 22, 32 are each defined by a respective second conduit 24b, 34b (See
In this manner, a single connection is formed that allows multiple aviation fuels to be transferred to the aircraft fuel tanks 10a, 10b from respective external fuel tanks 50a, 50b, with the external fuel tanks 50a, 50b (e.g. ground-based holding tanks) carrying the aviation fuel to be transferred to the aircraft 1. Refuelling a dual-fuel aircraft in this manner will provide considerable time savings over alternatives (such as using separate connections for each respective aviation fuel). In the example shown in
It will be understood that any suitable aviation fuel may be transferred through the connection, with a non-exhaustive list comprising jet fuel, sustainable aviation fuel (SAF), ammonia, liquid hydrogen, and gaseous hydrogen. In some examples, different compositions of aviation fuels may be transferred separately through the connection, with one example being Jet A and Jet A-1 aviation fuels.
The first connector 20 and second connector 30 may be arranged in various configurations.
The example described above requires careful alignment of the first connector 20 and second connector 30 to ensure that the first fluid path 21 of the first connector 20 aligns with the first fluid path 31 of the second connector 30, and similarly that the second fluid path 22 of the first connector 20 aligns with the second fluid path 32 of the second connector 30. In this way, the first fluid paths 21, 31 are fluidically sealed from the second fluid paths 22, 32.
In a further example shown in
In the example shown in
It will be noted that the cross-sections of the first and second conduits 24a, 24b shown in
Each of the abovementioned examples requires the first connector 20 and second connector 30 to be fixed at a specified orientation. This requires the second connector 30 to be positioned precisely, increasing the time to correctly align the connectors 20, 30, and preventing relative rotation of the connectors 20, 30 once connected such that excessive rotational force may damage the connection.
The abovementioned examples of
Accessing the flow from the first, inner conduit 24a could be achieved by creating a junction, with the first conduit penetrating through the outer wall of the second, outer conduit 24b wall-such as shown in
The first, inner conduits 24a, 34a could be supported within the second, outer conduits 24b, 34b by a bracket or extruded feature 55 to hold it centrally within the assembly, such as shown in
It will be appreciated that a number of options for sealing the conduits 24a, 24b, 34a, 34b may be suitable. Sealing the respective conduits 24a, 24b, 34a, 34a may be provided by a circumferential seal 56 at an end of one of the respective connectors 20, 30 (see
An advantage of the example shown in
It will be appreciated that in further examples, additional concentric conduits may be provided.
In some examples, one of the conduits 24a, 24b, 34a, 34b may be split into multiple sections. This split may be facilitated by the extruded feature 55 referred to in relation to
In the abovementioned examples, the connection has been discussed in relation to the fuelling of an aircraft 1. It will be appreciated that the connection has many other uses in the context of transferring fluids to and/or from the tanks of an aircraft 1.
In some examples, fuels may be transferred from the fuel tanks 10a, 10b into the external fuel tanks 50a, 50b. Such defueling of the aircraft 1 may be necessary for several reasons including maintenance and inspection. It will be appreciated that the connection may be used for simultaneous fuelling and defueling, with a first fuel transferred to a first fuel tank 10a whilst a second fuel 10b is transferred out of the second fuel tank 10b. These operations may be performed simultaneously or sequentially.
In some examples, the fluid paths 21, 22, 23 may converge at the first connector end or the second connector end. An example is shown in
Alternatively, fuel additives may be added from a first tank 50a and/or second tank 50b, either to a common fuel tank 10c or to respective fuel tanks 10a, 10b.
The arrangement may provide further benefits beyond refuelling and defueling. For instance, due to the presence of oxygen and fuel vapour in a fuel tank 10c, the concentration of oxygen in the ullage is maintained below a specified value to reduce the risk of combustion. To do this, the air in the ullage of the fuel tank 10c may be displaced by oxygen-depleted air (e.g. nitrogen or nitrogen enriched air) supplied from a first external tank 50a. In this case, the connection can also be configured to allow fuel to be supplied from a second external tank 50b.
Similarly, leak testing of fuel tanks 10c typically involves the use of a tracer gas, such as helium or nitrogen. The present connection can allow the tracer gas to be delivered to the fuel tank 10c whilst also being capable of functioning as a refuelling connection.
The fuel tank 10c may build up a quantity of water within a given region of the fuel tank 10c. This may be due to several reasons such as condensation within the tank 10c or separation of residual water in the fuel itself. The fuel often has a lower density than water such that the water collects towards the bottom of the tank 10c. Consequently, fuel tanks 10c are generally drained of water during regular maintenance. In at least some examples, the water within the fuel tank 10c may be extracted using the same connection as the fuel. For example, the water may flow through a first fluid path 21, 31 and the fuel may flow through a second fluid path 22, 32.
Whilst the above examples all relate to transfer to fuel tanks, it will be appreciated that the applicability of the connection is wider than this.
Where the word ‘or’ appears this is to be construed to mean ‘and/or’ such that items referred to are not necessarily mutually exclusive and may be used in any appropriate combination.
Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.
Number | Date | Country | Kind |
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2304778.0 | Mar 2023 | GB | national |