Component for containing fluid fuel

Abstract

A component (1) for containing fluid fuel to be shocked by a shockwave incident on the component (1). The component (1) includes a chamber (5) configured to contain the fluid fuel; and a fuel fill line (3) which is configured to allow the fluid fuel to be supplied to the chamber (5). At least a portion of the fuel fill line (3) follows a non-linear path.

Description

[0001] Component for Containing Fluid Fuel

[0002] This invention relates to a component for containing fluid fuel which is to be shocked by a shockwave incident on the component. In particular, this invention relates to components for containing fluid fuel which is to be shocked by a high pressure quasi-spherical shockwave incident on the component, creating high localised concentrations of energy within the fuel.

[0003] Components for containing fluid fuel to be shocked typically comprise a chamber within the component where the fuel is contained, and one or more fill lines, which take the form of radial tubes through the component. The fill lines allow fuel to be provided to the chamber. In such components, it is advantageous for the properties of the shockwave, and the condition of the fuel, to be strictly controlled, but fill lines introduce an inconsistency into the component which may interfere with the properties of the shockwave. Further, after the shockwave is incident on the component, fill lines may allow material (e.g. component material and / or external materials) to jet down the fill line and into the chamber, negatively impacting the condition of the fuel.

[0004] The present invention aims to provide alternative component designs which reduce the detrimental effects of fill lines.

[0005] When viewed from a first aspect, the invention provides a component for containing fluid fuel to be shocked by a shockwave incident on the component, the component comprising: a chamber configured to contain the fluid fuel; and a fuel fill line configured to allow the fluid fuel to be supplied to the chamber; wherein at least a portion of the fuel fill line follows a non-linear path.

[0006] The invention thus provides a component that is able to hold (e.g. contain) fluid fuel (e.g. liquid and / or gas), such that the fluid fuel can be exposed to a shockwave. In particular, the component may be configured to hold the fluid fuel in the chamber such that the fluid fuel can be exposed to a high pressure shockwave, leading to a collapse of the fluid fuel and a concentration of energy within the fluid fuel which may create the conditions necessary for nuclear fusion to occur.

[0007] It will be seen that, using a component in accordance with the invention, the fluid fuel may be supplied to the chamber via a fuel fill line, but the non-linear path of the fuel fill line reduces or even eradicates the presence of material jets and / or expelled gas shocks. As such, the interaction of the shockwave with the fluid fuel in the chamber are not affected by such material jets and / or expelled gas shocks, potentially leading to a more efficient fuel collapse and hence a higher fusion yield.

[0008] In embodiments, the component comprises a body. The body may comprise an inner wall and an outer wall. The outer wall may define the outer surface of the component. In some embodiments, at least a portion of the outer wall and / or the inner wall may be curved.

[0009] The (e.g. inner wall of the) body preferably defines the chamber configured to contain the fluid fuel. The (e.g. inner wall of the) body preferably defines the perimeter (surface area) of the chamber, e.g. the entire (surface area) perimeter (other than the fill lines) of the chamber.

[0010] The body preferably also defines the fuel fill line. Preferably the fuel fill line extends (e.g. through the body of the component) between the exterior of the component and the chamber. Thus, preferably the fuel fill line is configured to provide fluid communication between (i.e. to fluidly connect) the exterior of the component and the chamber, e.g. the chamber and the exterior of the component may be fluidly connected via the fuel fill line.

[0011] A linear path would be one in which the fuel fill line extends in a single direction between the outer wall and the inner wall of the component. It will be understood that the term ‘non-linear’ is intended to cover fill lines that contain at least one change of direction in the path of the fuel fill line between the outer wall and the inner wall of the component, e.g. curved paths, stepped paths, paths including one or more corners, zig-zag paths, etc.. Paths having a plurality of corners may be considered to be labyrinth paths. In embodiments, the (e.g. body of the) component (with the exception of the fuel fill line) is rotationally symmetrical about an axis of symmetry, e.g. an axis through (e.g. the centre of) the (e.g. body of the) component, e.g. through the (e.g. centre of the) chamber.

[0012] In embodiments, the (e.g. body of the) component is configured to (e.g. substantially) manipulate an input shockwave. It will be understood that in order to be configured to manipulate an input shockwave, the component is designed to manipulate a shockwave in a specific and deliberate way. Thus, an element that has some impact on the propagation of a shockwave simply as a result of its construction, but which is not designed or intended to have a specific effect on an input shockwave, will not be understood to be configured to manipulate an input shockwave.

[0013] In embodiments, manipulating the shockwave includes one or more of: accelerating the shockwave, decelerating the shockwave, reflecting portions of the shockwave (e.g. reflecting portions of the shockwave a plurality of times such that portions of the shockwave are superimposed), changing the shape of the shockwave by decelerating and / or accelerating different portions of the shockwave differently (e.g. slowing down a portion of the shockwave which is aligned with the chamber such that the shockwave may curve around the chamber).

[0014] In embodiments, the body is configured to spherically focus an input shockwave, e.g. towards the (e.g. centre of the) chamber.

[0015] In embodiments, the body has a thickness which is sufficiently large to effectively manipulate an input shockwave. The thickness of the body of the component may be defined as the shortest distance between the inner wall and the outer wall (e.g. in a plane perpendicular to the axis of symmetry of the component) (e.g. from the chamber to the exterior of the (body of the) component).

[0016] In embodiments, the thickness of the body is similar (e.g. substantially equal) to a maximum dimension (e.g. a diameter) of the chamber. In embodiments, the thickness of the body is greater than a maximum dimension (e.g. a diameter) of the chamber. In embodiments, an overall volume of the component (e.g. including the volume of the body and of the chamber defined by the body) is significantly greater than the volume of the chamber.

[0017] In embodiments, the thickness of the body is greater than 1 / 10th, e.g. greater than 1 / 5th, e.g. greater than 3 / 10ths, e.g. greater than 2 / 5ths, e.g. greater than half of a maximum dimension (e.g. diameter) of the chamber.

[0018] The (e.g. body of the) component may have any suitable and desired dimensions, e.g. to be determined by the specific application of the component. In one embodiment the component has a diameter and / or maximum dimension between 0.1 mm and 100 mm, e.g. between 1 mm and 50 mm, e.g. between 2 mm and 10 mm, e.g. approximately 3 mm, 5 mm or 8 mm.

[0019] In embodiments, the body has a thickness between 0.025 mm and 25 mm, e.g. between 0.25 mm and 12.5 mm, e.g. between 0.5 mm and 2.5 mm, e.g. approximately 0.75mm, 1.25 mm or 2 mm.

[0020] In embodiments, the chamber has a maximum dimension (e.g. diameter) between 0.05 mm and 50 mm, e.g. between 0.5 mm and 25 mm, e.g. between 1 mm and 5 mm, e.g. approximately 1.5 mm, 2.5 mm or 4 mm.

[0021] In embodiments, the width (e.g. diameter) of the fuel fill line is less than 100 microns, e.g. less than 50 microns, e.g. less than 10 microns, e.g. less than 5 microns, e.g. less than 2 microns.

[0022] In embodiments, the fill line has a proximal end, which opens into the chamber (e.g. forms an opening in the inner wall of the body), and a distal end, which opens to the exterior of the component (e.g. forms an opening in the outer wall of the body).

[0023] In embodiments, at least a portion of the fuel fill line follows a spiral path.

[0024] In such embodiments, the (e.g. shock front of the) incident (and propagating) shockwave is not perpendicular to the central axis of the fill line, as would be the case for a linear radial fill line and a shockwave incident in the radial direction. As such, an acute angle is formed at the point at which the shock front contacts the inner wall of the fill line. As the shock front propagates towards the chamber, the point moves down the fill line towards the chamber. If the point is moving down the fill line faster than the material jet and / or expelled gas shock, then the material jet and / or expelled gas shock will not reach the fuel in the chamber until after the shock-front has reached the fuel in the chamber, and hence the issues associated with material jetting, and / or the expelled gas shock may be avoided. It will be understood that the point is not physical matter that is moving, it is simply the point at which the shock front and the inner wall intersect.

[0025] In embodiments, at least a portion of the fuel fill line follows an Archimedean spiral path. At each point on the portion of the fill line on the Archimedean spiral path, the fuel fill line makes the same angle with the radial direction (i.e. the direction of propagation of an input spherical shockwave). The radial direction may be defined as the direction radially out from the centre of the (e.g. chamber of the) component, e.g. in a plane perpendicular to the axis of symmetry of the component. As such, the effect of the fuel fill line shape is the same across the whole of the portion of the fill line on the Archimedean spiral path.

[0026] In embodiments, the (e.g. body of the) component has a circular cross-section, e.g. in a plane perpendicular to the axis of symmetry of the component, e.g. in a plane in which the fuel fill line lies.

[0027] In embodiments, the chamber has a circular cross-section, e.g. in a plane in which the fuel fill line lies.

[0028] The shape of the component and / or of the chamber may be adapted in any suitable and desired way, e.g. depending on the shockwave properties and how they are to be manipulated. In embodiments, the (e.g. body of the) component and / or the chamber is substantially spherical.

[0029] In some embodiments the component has an oval cross-section, e.g. in a plane parallel to (e.g. containing) the axis of symmetry of the component. Thus, in some embodiments, the component is substantially ovoidal (egg-shaped). An ovoidal component may help to further manipulate (e.g. focus) the shockwave as it propagates into the component towards the chamber.

[0030] Preferably one end of the ovoidal component is more tapered and the other end is more rounded. Preferably the component has a maximum dimension (e.g. the longest dimension (major axis) of the ovoid) that is parallel (e.g. coaxial) with the axis of symmetry of the component.

[0031] In embodiments, an axis of symmetry of the (e.g. ovoidal) component is co-axial with an axis of symmetry of the (e.g. spherical) chamber.

[0032] In embodiments, the portion of the fuel fill line following an Archimedean spiral path forms an angle <|) with a radial direction of the component, in the plane in which the fuel fill line lies, at any point on the portion.

[0033] In embodiments the fuel fill line is configured such that <|) is greater than a first threshold. The first threshold may be the angle at which a material jet no longer reaches the chamber. As such, in such embodiments, the negative impact of a material jet on the fuel collapse may be avoided.

[0034] In embodiments, the first threshold is in the range 30° to 50°.

[0035] In embodiments, the fuel fill line is configured such that <|) is greater than a second threshold. The second threshold may be the angle at which an expelled gas shock no longer reaches the chamber. As such, in such embodiments, any negative impact (e.g. lack of symmetry of the overall shock state) on the fuel collapse may be avoided.

[0036] In embodiments, the fuel fill line is configured such that <|) is smaller than a second threshold. The second threshold may be the angle at which an expelled gas shock no longer reaches the chamber. As such, in such embodiments, an expelled gas shock may be allowed to reach the fluid fuel in the chamber. This may be advantageous since the expelled gas shock may act to pre-condition (e.g. pre-heat, or pre-compress) the fluid fuel. In embodiments, the second threshold is in the range 50° to 75°.

[0037] In embodiments the fuel fill line follows a path comprising one or more corners. The corners may act to slow down any material jets and / or expelled gas shocks

[0038] In embodiments, one or more of the one or more corners are through approximately 90°.

[0039] In embodiments (e.g. when the component has a circular cross-section) the fuel fill line comprises one or more circumferential portions and one or more radial portions, e.g. in a plane in which the fuel fill line lies. In such embodiments, any material jets and / or expelled gas shocks which are generated in the radial portions may be destroyed by a subsequent circumferential portion.

[0040] In embodiments, the fuel fill line may comprise one or more spiral (e.g. Archimedean spiral) portions. In embodiments, the fuel fill line portion proximal to the chamber (e.g. the final portion) may comprise a spiral portion. Such embodiments may be advantageous compared to the fuel fill line portion proximal to the chamber being radial, because any material jet and expelled gas shock that is generated in this final radial portion will be allowed to propagate into the chamber with little resistance. However, by forming the fuel fill line portion proximal to the chamber as a spiral portion, the advantages discussed herein with relation to spiral fill lines may be realised for the portion proximal to the chamber.

[0041] In embodiments, the component comprises a first part and a second part, wherein the first and second parts are configured to combine, via an abutting face on each of the first and second parts, to define the chamber. Such embodiments may aid the manufacture of the component.

[0042] The first part and the second part may be connected in any suitable and desired way to form the component. In some embodiments, the first part may rest (e.g. on top of) the second part, e.g. such that the first part and the second part abut against each other. Preferably the first part and the second part together form the body of the component. Preferably the first part and the second part together define the chamber.

[0043] The first part and the second part may be any suitable and desired shape. In some embodiments, the first part and / or the second part of the component are substantially rotationally symmetric about an axis (i.e. an axis of symmetry), e.g. an axis through (e.g. the centre of) the (e.g. body of the) component, e.g. through the (e.g. centre of the) chamber. In some embodiments, the first part and the second part share the same axis of symmetry when they are assembled in the component, such that the component is rotationally symmetric about the axis of symmetry.

[0044] In some embodiments, the first part and / or the second part have a substantially circular cross-section, e.g. in a plane perpendicular to their axis of symmetry. In some embodiments, the diameter of the circular cross-section may vary across the first part and / or the second part (e.g. along the length of the axis of symmetry).

[0045] In embodiments, the first part and the second part each comprise a body. The body (of the first part and / or the second part each) preferably comprises an inner wall and an outer wall. The outer wall may define the outer surface of the first part and / or the second part respectively (and thus the outer surface of the (e.g. body of the) component, when the first part and the second part are assembled to form the component). In some embodiments, at least a portion of the outer wall and / or the inner wall may be curved.

[0046] The (e.g. inner wall of the) first part and the (e.g. inner wall of the) second part preferably together define the chamber, e.g. when the first part and the second part are assembled to form the component. The (e.g. inner wall of the) first part and the (e.g. inner wall of the) second part preferably together define the perimeter (surface area) of the chamber, e.g. the entire (surface area) perimeter (other than the fill lines) of the chamber.

[0047] In embodiments, the fuel fill line is formed as a groove in the abutting face of one or both of the first and second parts. For example, the fuel fill line may be etched or machined into the (surface of the) first part and / or the (surface of the) second part. In some embodiments, the first part and / or the second part are formed in a mould which includes a protrusion in the desired shape of the fuel fill line.

[0048] In embodiments, the component comprises a plate configured to be sandwiched between the abutting faces of the first and second parts, and wherein the fuel fill line is formed as a groove or slot in the plate. Such embodiments may aid the manufacture of the component, as the fuel fill line may be formed separately from the first and second parts.

[0049] In embodiments, in a plane in which the fuel fill line lies, the component and the chamber have a circular cross-section (e.g. in a plane in which the fuel fill line lies). Preferably the plate is annular.

[0050] In embodiments, the component comprises a plurality of fill lines (e.g. two fill lines). In embodiments comprising two fill lines, the first line may be configured to be connected to a fuel supply in order to supply fluid fuel to the chamber, and the second fill line may be connected to a pressure sensor. By measuring the pressure at the second fill line, it may be determined whether or not fluid fuel has reached the chamber from the first fill line (e.g. that the fill line is not blocked or faulty), since the chamber is located between the first and second fill lines (e.g. the first and second fill lines are fluidly connected via the chamber). In embodiments, the pressure sensor may be replaced with any other type of sensor capable of determining whether or not there is fluid fuel in the second fill line.

[0051] The component may be formed of any suitable and desired material. In some embodiments, the component is formed from a high Z material. In some embodiments, the component is formed of a metal and / or a metal alloy. For example, the component may be formed of one or more of: gold, tungsten, copper, tantalum and / or an alloy comprising one or more of gold, tungsten, tantalum and / or copper. These materials may be advantageous owing to their high density, high toughness and / or high strength.

[0052] In accordance with a second aspect of the invention, there is provided a system comprising: a component as outlined herein; and an apparatus configured to generate a (e.g. quasi-spherical) shockwave to be incident on the component.

[0053] The (e.g. body of the) component may be arranged to be used with any suitable and desired fuel. In embodiments, the fluid comprises a fuel, e.g. a fuel for nuclear fusion. In embodiments the fluid comprises one or more (e.g. all) of: deuterium gas, liquid deuterium, tritium gas, liquid tritium, deuterium-tritium (DT) gas, and deuterium-tritium (DT) liquid.

[0054] It will be understood that where used herein, the term “shock-impedance” is intended to mean “the pressure which must be applied to a medium in order to impart a unit particle velocity to some of the medium” (Henderson, ‘On the refraction of shock waves’, Journal of Fluid Mechanics, Volume 198, January 1989, pages 365-386). This is equal to the product of the shock speed and the density of the un-shocked material.

[0055] In embodiments, the component comprises a plurality of fill lines (e.g. two fill lines).

[0056] In embodiments comprising two fill lines, the first line is configured to be connected to a fuel supply in order to supply fluid fuel to the chamber, and the second fill line is configured to be connected to a pressure sensor.

[0057] In embodiments, the system comprises a pressure sensor fluidly connected to the second fill line.

[0058] Certain embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0059] Figure 1 shows a cross-sectional view of a component with a conventional fill line;

[0060] Figure 2 is a simulation still of the output of a conventional fill line;

[0061] Figure 3 shows a cross-sectional view of a component with a spiral fill line;

[0062] Figure 4 shows a schematic drawing of the component of Figure 3 in use;

[0063] Figures 5a-d show simulation stills for a shockwave incident on components with spiral fill lines at varying angles; Figure 6a-d show simulation stills focussed on the output of spiral fill lines at varying angles;

[0064] Figure 7 shows a cross-sectional view of a component with another fill line design;

[0065] Figure 8 shows a close-up cross-sectional view of a component with another fill line design;

[0066] Figure 9 shoes a perspective exploded view of a component having a spiral fill line;

[0067] Figure 10 shows a perspective exploded view of a component with another fill line design;

[0068] Figure 11 shows a perspective exploded view of a component having another fill line design; and

[0069] Figure 12 shows a perspective exploded view of another component.

[0070] It will be understood that where used herein, the terms “top”, “bottom”, “up”, “down”, “side”, “base”, “vertical”, “horizontal”, etc. are included for clarity and are intended to refer to the orientation shown in the enclosed Figures. It will be appreciated that, in use, the components and systems may operate in any suitable and desired orientation.

[0071] It will be understood that each of the components described herein may be configured to be used at part of a nuclear fusion process. As such the fluid fuel mentioned herein may be a fusionable fuel such as deuterium gas. If the fuel is put under a sufficiently high pressure it will collapse, resulting in intense pressures and temperatures being generated in the collapsed fluid fuel, which may be sufficient to initiate fusion.

[0072] Figure 1 shows a cross-sectional view of a component 1 having a conventional radial fill line 3. In the plane in which the cross-section is taken, the component 1 is circular. The component 1 defines an interior chamber 5 which is defined by a chamber wall 8. In the plane in which the cross-section is taken, the interior chamber 5 is also circular. The fill line 3 allows fluid (e.g. gaseous) fuel to enter the interior chamber 5. Although the shape of any of the components described herein may be adapted depending on the shockwave properties which are desired, in the illustrated embodiment, the component 1 is spherical. The fill line 3 has a proximal end 7, which opens into the chamber 5, and a distal end 9, which opens to the exterior of the component 1.

[0073] In use, fuel is provided to the distal end 9 of fill line 3, the fuel passes through the fill line 3 and into the chamber 5 at the proximal end 7.

[0074] Operation of linear radial fuel lines will now be explained in relation to Figure 2, which shows a still taken from a simulation of a (e.g. spherical) shockwave being incident on a component 1 having a linear radial fill line 3.

[0075] An issue with linear radial fill lines such as the fill line 3 in component 1 is that as the shock in the component 1 reaches the fill line 3, the shockwave forces lower density material into the fill line 3. This lower density material may comprise lower density material used within the component itself, as well as lower density material from elements of a system in which the component is employed.

[0076] For example, the component may be suspended in a volume of PMMA (Polymethyl methacrylate). This material forms a jet that travels faster than the shock in the component 1 , such that the material jet penetrates the fuel in the chamber 5 before the shockwave reaches the fuel. This introduces an impurity in the fuel, which has a negative impact on the concentration of energy generated by the shockwave. The material jet 11 can be seen clearly in the simulation still of Figure 2. Further, it can be seen that the material jet 11 has reached the chamber 5 significantly ahead of the shock-front 24 (visible as the darker region in Figure 2). As such, the fuel in the chamber 5 is significantly contaminated before the shockwave reaches the chamber 5.

[0077] Another potential issue with linear radial fill lines, in the case of gaseous fuel, is the expelled gas shock 13 which is also shown in Figure 2. The expelled gas shock is a product of the residual fuel which is present in the fill line 3. This fuel is shocked before the shockwave reaches the fuel in the chamber 5, and the gas shock in the fill line 3 is then expelled into the chamber 5, resulting in an irregularity in the fuel inside the chamber. This irregularity may have a negative impact on the properties of the fuel collapse. In embodiments, however, the expelled gas shock may be advantageous, as will be explained below.

[0078] Figure 3 shows a cross-sectional view of a component 21 in accordance with an embodiment of the invention. The component 21 has a chamber 25 defined by a chamber wall 26, and a fill line 23. The fill line 23 has a proximal end 27 and a distal end 29, and is formed as a section of an Archimedean spiral (as defined by https: / / mathworld.wolfram.com / ArchimedesSpiral.html).

[0079] With regards to the provision of fuel to the chamber 25, the fill line 23 functions in the same way as fill line 3 provided in component 1. At its proximal end 27, the fill line 23 makes an angle 0 with the chamber wall 26 (i.e. a tangent 28 to the chamber wall 26 at the location of the proximal end 27). Owing to the Archimedean spiral shape of the fill line 23, at every point on the fill line 23, the fill line 23 also makes the angle 0 with the tangent to a spherically impinging shockwave at all points on the fill line 23. As such, at any given point, the fill line makes an angle <|) with the radial direction 30 where <|) = 0 - 90°.

[0080] The function of the spiral fill line 23 will be described with reference to Figure 4, which shows a schematic diagram of the spiral fill line 23 whilst a shockwave is propagating through the component 21 towards the chamber 25. For the purposes of the following explanation, the situation depicted by Figure 4 will be described in two dimensions. As such, the fill line will be considered to have an inner wall and an outer wall, wherein the inner wall is the wall which is closer to the chamber 25.

[0081] It can be seen from Figure 4, that as a result of the spiral shape of the fill line 23, the shock front 24 is not perpendicular to the central axis of the fill line 23, as is the case for a linear radial fill line 3. As such, an acute angle is formed at the point 28 at which the shock front 24 contacts the inner wall of the fill line 23. As the shock front 24 propagates towards the chamber 25, the point 28 moves down the fill line 23 towards the chamber. If the point 28 is moving down the fill line 23 faster than the material jet 11 then the jet will not reach the fuel in the chamber 25 until after the shock-front 24 has reached the fuel in the chamber 25, and hence the issues associated with material jetting may be avoided. Similarly, if the point 28 is moving down the fill line 23 faster than the expelled gas shock 13, then no expelled gas shock will reach the fuel in the chamber 25 until after the shock-front 24 has reached the fuel in the chamber 25, and hence any issues associated with an expelled gas shock 13 may be avoided. It will be understood that the point 28 is not physical matter that is moving, it is simply the point at which the shock front and the inner wall intersect.

[0082] The larger the value of 0, the faster the point 28 will move. As such, there is a threshold value of 0 at which the point 28 is travelling faster than the material jet, and a value of 0 at which the point 28 is travelling faster than the expelled gas shock. For the illustrated component 21, these thresholds have been determined using simulations, as is explained in relation to Figures 5a-d.

[0083] Each of Figures 5a-d show four stills taken at different times during a simulation of a spherical shockwave being incident on a component 21 in accordance with the component shown in Figure 3. The first, second, third, and fourth stills in each time series are taken at t = 0, t = 100 ns, t = 200 ns, and t = 280 ns respectively, where t = 0 is the point at which the shock front 24 is first incident on the outer surface of the component 21 and the subsequent stills show the progression of the shock front 24 through the component 21.

[0084] The component 21 shown in Figure 5a has a spiral fill line 23 with 0 = 120°. In Figure 5a, it can be seen in both the third, and most clearly, the fourth still, that a large jet of material is entering the fuel in the chamber 25.

[0085] The component 21 shown in Figure 5b has a spiral fill line 23 with 0 = 130°. In Figure 5b, it can be seen in the fourth still that a material jet is entering the fuel in the chamber 25, but this jet is much less significant than the jet which is present in Figure 5a. As such, the increased value of 0 reduces the jetting effect.

[0086] The component 21 shown in Figure 5c has a spiral fill line 23 with 0 = 150°. In

[0087] Figure 5b, it can be seen that no material jet is entering the fuel in the chamber 25. Likewise, the component 21 shown in Figure 5d has a spiral fill line 23 with 0 = 160°, and no material jet is entering the fuel in the chamber 25.

[0088] Figures 6a-d also show simulation stills which are all taken at t = 260 ns. The stills of Figures 6a-d are close-ups of the proximal end of the spiral fill line such that any expelled gas shock 13, and material jet 11 can be seen more clearly. The fill line 23 of Figure 6a has a value of 0 = 120°, the fill line 23 of Figure 6b has a value of 0 = 140°, the fill line 23 of Figure 6c has a value of 0 = 150°, and the fill line 23 of Figure 6d has a value of 0 = 160°.

[0089] In Figure 6a, both an expelled gas shock 13 and a material jet 11 can be seen. In Figures 6c and 6d, neither a material jet 11 , nor an expelled gas shock 13, can be seen. In Figure 6b, no material jet 11 is present, but an expelled gas shock can be seen ahead of the shock front 24 inside the fill line 23.

[0090] It appears from the simulations illustrated in Figures 5a-d, and 6a-d, that the threshold value of 0 at which the point 28 is travelling faster than the material jet (and so no material jet enters the chamber 25) is between 120° and 140°, and the threshold value of 0 at which the point 28 is travelling faster than the expelled gas shock is between 140° and 150°. Since <|> = e - 90°, if the thresholds are considered as values of <j> (i.e. in terms of the angle made with the radial direction) then the threshold value of <j> at which the point 28 is travelling faster than the material jet (and so no material jet enters the chamber 25) is between 30° and 50°, and the threshold value of <j> at which the point 28 is travelling faster than the expelled gas shock is between 50° and 60°, for this example.

[0091] If the component is designed to eradicate any material jet and any expelled gas shock, then it can be seen that a large value of 0 should be used. However, a spiral fill line with a large 0 value may introduce additional complications. If the value of 0 is large, then the fill line will be longer and so the overall density of the component will be reduced. This reduction in density may affect how the shockwave propagates through the component and hence potentially affect the successful collapse of the fuel. As such, a compromise between minimising material jets and / or gas shocks, and maintaining sufficient density of the component may be found.

[0092] As can be seen from Figures 6a-d, the expelled gas shock threshold is greater than the material jet threshold. In embodiments, a value of 0 may be selected which is between the material jet threshold and the expelled gas shock threshold such that an expelled gas shock is present but a material jet is not. In embodiments, it may be advantageous to use the expelled gas shock to pre-condition (i.e. pre-heat / pre- compress) the fuel in the chamber before the shock-front arrives at the chamber 25.

[0093] Figure 7 shows a cross-sectional view of a component 31 having a fill line 33 which comprises a plurality of corners 32 in the path of the fill line 33. In the illustrated embodiment, each corner 21 is a 90° corner. As a result of the corners 32, the fill line 23 comprises a plurality of radial portions 36, and a plurality of circumferential portions 34. Each pair of circumferential portions 34 are connected by a corner 32 to a radial portion 36. Hereinafter, the fill tube design shown in Figure 7, comprising a plurality of corners, will be referred to as a “labyrinth” fill tube.

[0094] Like the spiral fill line 23 shown in Figure 3, the labyrinth fill tube 33 is designed to reduce or eradicate the presence of a material jet and / or an expelled gas shock at the chamber 35. The material jet and / or expelled gas shock is forced to change its direction at each of the corners 32. This change in direction reduces the speed of the material such that the shock-front arrives at the fuel in the chamber 35 before any material jet and / or the expelled gas shock.

[0095] More specifically, the radial portions 36 represent the worst-case scenario, and as such, material jets and expelled gas shocks will be allowed to propagate freely in these portions towards the chamber 35. However, the circumferential portions 34 represent the best-case scenario, since they are parallel to the shock front (and hence perpendicular to the direction of propagation) so the material jets and expelled gas shocks are not allowed to propagate towards the chamber 35 at all. The intention is that any jet and shock which is generated in a radial portion 36 will be eradicated by the subsequent circumferential portion 34. The shape of the labyrinth fill tube 33 (including the number of radial portions 36, circumferential portions 34 and / or corners 32) may be varied in order to help ensure that the shock-front arrives at the fuel in the chamber 35 before any material jet and / or the expelled gas shock. As such, if the component is designed to eradicate any material jet and any expelled gas shock, then a large number of corners 32 may be used.

[0096] However, if the fill line 33 includes a large number of corners 32, then the fill line 33 will be longer and so the overall density of the component 31 will be reduced. This reduction in density may affect how the shockwave propagates through the component and hence potentially affect the successful collapse of the fuel. As such, a compromise between minimising material jets and / or gas shocks, and maintaining sufficient density of the component may be found.

[0097] It will be seen that the gas fill line 33 shown in Figure 7 has a final portion, proximal to the chamber 35, that is a radial portion 36. As such, any material jet and expelled gas shock that is generated in this final radial portion will be allowed to propagate into the chamber 35 with little resistance.

[0098] Figure 8 shows a cross-sectional view of a component 41 having a fill line 43. The fill line 43 in the component 41 shown in Figure 8 is a variant of the fill line 33 in the component 31 shown in Figure 7, and follows the same path as fill line 43, except the final (proximal) radial portion is replaced with a spiral portion 42. In the illustrated embodiment, the spiral portion follows the path of an Archimedean spiral and functions as discussed above in relation to Figures 2 and 3.

[0099] Figure 9 shows a perspective view of the component 21 (e.g. the component 21 shown in Figure 3). In this embodiment, the component 21 is formed from a first part 4 and a second part 6. The first part 4 and the second part 6 each have abutting faces 14 and 16. When the abutting faces 14 and 16 are brought together, the first and second parts 4, 6, combine to define the chamber 25 in the component 21.

[0100] As can be seen from Figure 9, the fill line 23 is formed as a groove in the abutting abutting face 16. As such, the fill line 23 may have an approximately semi-circular cross-section in the plane perpendicular to its axis. It will be understood that the fill line 23 may be formed as a groove in the abutting face 14 of the first part 4.

[0101] Further, in embodiments where a tube-shaped fill line is desired (e.g. having a circular cross-section in the plane perpendicular to its axis), complementary grooves may be cut into both the abutting faces 14, 16 of the first and second parts 4, 6, such that when the first and second parts are aligned, a tubular fill line is defined. An advantage of the fill line being cut in only one abutting face is that rotational alignment of the first and second parts 4, 6, may not be required.

[0102] Although in this embodiment, the component 21 is formed from two parts 14, 16 it will be understood that the component 21 may be formed from any suitable and desired number of parts.

[0103] Figure 10 shows a perspective view of a component 51 which is formed of a first part 54 and a second part 56 with a joint 10 in between the first and second parts 54, 56, the joint 10 comprising a step. In this embodiment, when viewed in a crosssection taken in a plane parallel to the axis 12 of the component 51 , the joint 10 comprises a first radial portion 10a, a vertical portion 10b and a second radial portion 10c. The radial portions 10a, 10c are also substantially perpendicular to the vertical portion 10b. In the illustrated embodiment, the vertical portion 10b and the second radial portion 10c are formed by an annular protrusion on the abutting face 516 of the second part 56 and a complementary recess on the abutting face of the first part 54.

[0104] The fill line 53 of the component 51 is a labyrinth fill line as described in relation to Figure 7 and as such comprises a plurality of radial portions, circumferential portions 533, and corners. Further, the fill line 53 is formed as a groove in the abutting face 516 of the second part 56, in a similar way as described in relation to Figure 9. As a result of the vertical portion 10b of the joint 10, the fill line 53 comprises a vertical portion 57. This vertical portion 57 acts in the same way as the circumferential portions 533 since it is parallel to the shock front. Figure 11 shows a perspective view of a component 61 which is a variant of the component 51 of Figure 10. Rather than the labyrinth fill line 53, component 61 comprises a spiral fill line 63 which is formed, and functions, as described in relation to Figures 2, 3 and 9. The component 63 is otherwise identical to the component 53 and so the description of the joint and abutting faces given in relation to Figure 10 is equally applicable to Figure 11.

[0105] Figure 12 shows an exploded view of component 71 that is formed in an alternative way. Like the components 41, 51 and 61 shown in Figures 9, 10 and 11 , the component 71 is formed in two parts which fit together to form the chamber 75. However, unlike the components 41, 51 and 61 shown in Figures 9, 10 and 11, the fill line 73 of the component 71 shown in Figure 12 is not defined by either of the main parts. Rather, the component 71 comprises a plate 72 that is sandwiched between the two halves. It is the plate 72 which defines the fill line 73.

[0106] Any of the methods described above (laser etching, machining, etc.) may be used to form the fill line 73 in the plate 72. In Figure 12, the component 71 has a labyrinth fill line, but it will be understood that a plate 72 may be used to define any suitable fill line shape, for example a spiral. Forming the fill line in a plate may be advantageous from a manufacturing perspective, especially when performing experimentation where many different fill line designs are being tested. By forming the fill line in the plate, the main parts of the component may be standardised, which aids with mass production.

[0107] In each of the illustrated embodiments, only a single fill line is shown. In embodiments, a plurality of fill lines (e.g. two fill lines) may be present in components according to this disclosure. In embodiments comprising two fill lines, the first line may be connected to a fuel supply in order to supply fluid fuel to the chamber, and the second fill line may be connected to a pressure sensor. By measuring the pressure at the second fill line, it may be determined whether or not the fluid fuel has reached the chamber from the first fill line (e.g. that the fill line is not blocked or faulty) since the chamber is located between the first and second fill lines. In embodiments, the pressure sensor may be replaced with any other type of sensor capable of determining whether or not there is fluid fuel in the second fill line. In each of the illustrated embodiments, the entire fill line has the described nonlinear shape. In embodiments, however, the fill line may only have a non-linear portion (e.g. the portion proximal to the chamber). This non-linear portion may be sufficient to destroy any material jet and / or expelled gas shock which was present in a portion of the fill line which is linear (e.g. a portion which is distal from the chamber). Such embodiments may be easier to manufacture.

[0108] The components described herein may be manufactured in any suitable and desired way. In some embodiments, the components may be formed over a removable mandrel. For example, the mandrel may be dissolvable or collapsible to allow the mandrel to be removed from the component after it has been formed. In some embodiments, the component may be formed in a mould. For example, the component may be formed of a metal that is cast in a mould.

[0109] The component may be formed as a single piece or as two or more separate parts. If the component is formed as a single piece, it may later be separated (e.g. cut using a machine or a laser) into two or more parts. Even if the component is formed in two or more parts at least one surface of the component may be cut (e.g. using a machine or a laser). This may help to ensure that the two or more parts of the component fit together. It is important that fluid fuel does not leak from the interior chamber of the component and so the components need to be precisely formed or cut to ensure a flush fit between parts.

[0110] The two or more parts may be brought together to form the component in any suitable and desired way. In some embodiments, the first part of the component is lowered onto the second part of the component. In order to facilitate this, the first part of the component and the second part of the component are configured to move relative to one another in at least one direction.

[0111] The components described herein may be formed from a single material or a combination of different materials. In embodiments, the components are formed from a single material, wherein that single material is a high shock-impedance material such as tantalum. In other embodiments, the components may be formed of a combination of high and low shock-impedance materials (e.g. in layers). The components may comprise one or more of: tungsten, steel, aluminium, gold, PMMA, copper.

Claims

Claims1. A component for containing fluid fuel to be shocked by a shockwave incident on the component, the component comprising: a chamber configured to contain the fluid fuel; and a fuel fill line configured to allow the fluid fuel to be supplied to the chamber; wherein at least a portion of the fuel fill line follows a non-linear path.

2. The component as claimed in claim 1 , wherein at least a portion of the fuel fill line follows a spiral path.

3. The component as claimed in claim 2, wherein at least a portion of the fuel fill line follows an Archimedean spiral path.

4. The component as claimed in claim 1 , 2 or 3, wherein in a plane in which the fuel fill line lies, the component has a circular cross-section.

5. The component as claimed in claim 4, wherein the portion of the fuel fill line following an Archimedean spiral path forms an angle <|) with a radial direction of the component, in the plane in which the fuel fill line lies, at any point on the portion.

6. The component as claimed in claim 5, wherein the fuel fill line is configured such that <|) is greater than a first threshold.

7. The component as claimed in claim 6, wherein the first threshold is in the range 30° to 50°.

8. The component as claimed in claim 5, 6 or 7, wherein the fuel fill line is configured such that <|) is greater than a second threshold.

9. The component as claimed in claim 5, 6 or 7, wherein the fuel fill line is configured such that <|) is smaller than a second threshold.

10. The component as claimed in claim 8 or 9, wherein the second threshold is in the range 50° to 60°.

11. The component as claimed in any one of the preceding claims, wherein the fuel fill line follows a path comprising one or more corners.

12. The component as claimed in claim 11 , wherein one or more of the one or more corners are through approximately 90°.

13. The component as claimed in claim 11 or 12, wherein, in a plane in which the fuel fill line lies, the component has a circular cross-section and the fuel fill line comprises one or more circumferential portions and one or more radial portions.

14. The component as claimed in any one of the preceding claims, wherein the component comprises a first part and a second part, wherein the first and second parts are configured to combine via an abutting face on each of the first and second parts, to define the chamber.

15. The component as claimed in claim 14, wherein the fuel fill line is formed as a groove in the abutting face of one or both of the first and second parts.

16. The component as claimed in claim 14, wherein the component further comprises a plate which is configured to be sandwiched between the abutting faces of the first and second parts, and wherein the fuel fill line is formed as a groove or slot in the plate.

17. The component as claimed in claim 16, wherein, in a plane in which the fuel fill line lies, the component and the chamber have a circular cross-section, and wherein the plate is annular.

18. A system comprising: a component as claimed in any one of the preceding claims; and an apparatus configured to generate a shockwave to be incident on the component.

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