Wave-riding ship hull, whose trailing edge is designed in the form of a pointed arch.

Abstract

Wave-riding ship hull, which displaces water predominantly under the ship by means of a skirt-flanked sill, characterized in that this sill (1) is bulged out in the direction of the midship in the form of a pointed arch.

Description

[0001] The invention relates to a wave-riding ship hull with a breakaway sill of the type described in German utility model number 20 2022 002 819. This utility model was registered with the German Patent and Trademark Office on August 5, 2022; that is, this specific hull shape has been known since that date.

[0002] While ships with a conventional hull shape displace the water to be moved forward predominantly to the left and right (whereby this energy expended for the forward movement is subsequently inevitably lost), a wave-riding ship hull instead forces this water predominantly downwards in the area of ​​its bow - with the intention of taking back the energy that was previously invested in displacing it downwards when the water rises again under the stern, i.e. to recuperate it.

[0003] Several designs of such a wave-riding ship hull are known, all aiming to direct the displaced water as far and as deeply as possible beneath the ship. For example, one version, published in 2013 (German utility model number: 202013 004 518.3), directs the water down a forward ramp, flanked by sheet-pile-like skirts, and then back up under the stern via a rear ramp, also flanked by skirts. The force of the upward-moving water can then be converted into propulsion. However, channeling the water over skirts inevitably results in an additional wetted surface area, which increases water friction and thus significantly reduces the amount of energy recovered.

[0004] Also known is an international patent (AZ 20 2013 004 518.3) granted to a US inventor in 2015, in which the water to be displaced during forward travel is also guided under the bow using skirts - however, without taking any further measures to then recuperate this potential under the stern.

[0005] Another wave-riding ship hull version from 2021 (see German utility model number 10 2021 004 029.5) addresses the aforementioned shortcoming of "the significant increase in the wetted surface area of ​​the ship's hull due to the installation of large skirts" by completely omitting the skirts under the stern. That this is easily possible stems from the principle recognized and formulated by the Swiss scientist Daniel Bernoulli in 1783: "In accelerated media, pressure decreases." Since the flow of rising water under the stern represents "moving water"—that is, water subjected to only low pressure (while the surrounding water to the left and right is "statically still water," thus exhibiting a higher pressure level)—an rising water flow under the stern remains stable even without guiding measures (such as...).(The skirts) are always "trapped" – and simply cannot escape due to "the nature of things". Therefore, it is clear that the rising water current under the stern inevitably transfers, indeed must transfer, the full potential recuperation yield to the rear ramp of such a wave-riding hull. The complete elimination of the rear skirts on an improved wave-riding hull designed in this way thus results in an enormous reduction in wetted surface area – which then manifests itself in significantly reduced water friction. This is shown in the aforementioned utility model # 10 2021 004 029.5. This resulting, significant reduction in resistance was then immediately used to further increase the effectiveness of this wave-riding ship hull type by installing extendable skirt extensions in the bow area. This forced even more of the water flowing towards the bow deeper under the ship, thus further increasing the recuperation yield under the stern. However, experts criticized the necessary mechanical effort as disproportionate, i.e., significantly too high.

[0006] Another utility model from 2022, called "Wave-riding ship hull with breakaway edge sill" (AZ10.2022 002 819), is also known. It demonstrates a way to significantly reduce the wetted surface area in the forward skirts (to force the water flowing towards the bow under the ship) without any mechanical effort. This is made possible by integrating a new element called a "breakaway edge sill." This design utilizes the fact that, due to the inertia of its mass, accelerated water retains a certain speed even when there are no longer any channeling skirts to the left and right (to prevent it from breaking away).

[0007] To achieve a short and strong acceleration of the water flow under the bow, a dredger-shovel-shaped bow was provided, flanked laterally only by minimal skirting surfaces, in order to accelerate the water flow far below the sector with a horizontal ship bottom, without the need for any lateral guide elements down there.However, physicists and fluid dynamics experts object, arguing that the swirl of the water flow is not strong enough to guarantee that the descending water in the bow area then flows "linearly" far below the midsection of the hull (i.e., the area where the ship's bottom is horizontal), where it receives renewed acceleration due to the suction generated by the rising ramp under the stern. In other words, "according to Bernoulli's principle," it would then reliably remain channeled until it rises under the stern. "The water accelerated under the ship would already break out to the left and right under the midsection—the stretch with a horizontal hull bottom to the stern is simply too long," is the general consensus. "Assuming the typical cruising speed of large ships (of approximately...")At a service speed of 20 knots in overseas shipping mode, the impetus that the water receives at the bow is simply too low to keep it under the ship for the required duration.

[0008] However, if one were to consider increasing the speed as a solution to counter this situation, it would be uneconomical; if one were to plan for a shorter, possibly wider hull, this would also be counterproductive – because it would simply violate the time-honored design maxim that states: "Length matters".

[0009] The task must therefore be to design a wave-riding ship hull with a breakaway sill in such a way that the water flow, which is forced under the ship when it moves forward, is influenced – not to say “shaped” – in such a way that it reliably flows linearly backwards over the area of ​​the horizontal bottom of the ship without breaking out to the left or right – until it is then caught by the anticipatory upward suction channeling under the stern.

[0010] This problem is solved by a wave-riding ship hull with a novelly designed breakaway edge sill according to claims 1 - 10.

[0011] The trailing edge sill positioned under the bow of a wave-riding ship's hull is now given a pronounced indentation towards the midships, resembling a pointed arch. This automatically results in the forward, downward-leading ramp, which (starting from the skirt attachments on the left and right) runs towards this pointed trailing edge sill on the ship's bottom, forming a concave hollow – thus appearing almost "as an inverted, turned-up bow." This resulting shape could also be described as "the negative image" of a conventionally shaped bow.

[0012] When water flows towards such a shaped underwater bow section as the ship is moving forward, it is initially caught by the skirts on the left and right. This water flow is then accelerated exponentially downwards by the curvature of the downward ramp, meaning its speed increases dramatically, until it reaches the sill of the hull – at which point it detaches from the ship. Due to inertia, the water flow continues its downward path for a considerable distance until an equilibrium is reached again due to the increasing water pressure at depth. The downward movement of the water flow thus comes to a standstill in the center beneath the hull section, where the ship's bottom is horizontal.However, the upward-leading ramp located beneath the stern, following this horizontal sector, sends out a suction effect ahead of it—almost as a "messenger of its power"—anticipating its actual, defined position. This suction effect causes a renewed acceleration of the water flow beneath the horizontal hull sector of the ship, this time upwards, back towards the water's surface. The flow then ascends this ramp beneath the stern in a linear and targeted manner, "as if on rails," all the way to the water's surface behind the ship's stern. The fact that no further channeling measures, such as skirts, are necessary was already explained at the beginning of this text, based on the findings formulated by the Swiss scientist Bernoulli in 1783 → the gist: "In accelerated media, pressure decreases."This means that the upward-flowing water under the stern could never deviate from its path or even "break out" to, for example, seek a different route to the side of the ship (since, according to Bernoulli's principle, the flowing water under the stern logically has a lower pressure than the surrounding water to the left and right of the ship, which is in a static state – thus giving it a higher pressure potential in comparison). The rising water flow under the stern therefore has no other option than to transfer its inherent force – completely and in its entirety – to the stern, thereby making it entirely available for recuperation.

[0013] The recuperative force generated in this way is equivalent to an additional thrust in the ship's direction of travel, which can significantly reduce the engine power of a vessel with this type of hull design – resulting in substantial fuel savings. Crucially, the length of the horizontal hull section – or, in other words, the distance "D" between the forward and aft ramps – is essential for the flow pattern described above to actually develop as required under the bottom of such a wave-riding hull with a pointed-arch trailing edge.If this sector is too long, meaning the distance is too great, it becomes impossible to maintain a consistently linear, backward flow beneath the horizontal hull bottom sector. In other words, the suction from the aft ramp takes effect too late, and the water flow becomes too slow – consequently, it can "escape" to the left and right of the ship. Conversely, if the distance is too short, not only is valuable cargo space lost (a horizontal hull bottom with parallel sides represents the optimal space utilization possible for a container ship), but the maximum possible recuperation capacity is also wasted. This is because the water flow emerging "too late" means a loss of valuable recuperation distance (since, for example, perhaps only half the area of ​​the aft, upward-leading ramp is actually reached by the emerging water flow).

[0014] In general, the length of sector "D" (with the horizontal hull bottom between the two ramps) must be designed to match the ship's standard service speed to ensure optimal energy recuperation performance while traveling at that speed. Therefore, optimal energy recuperation performance cannot be expected during empty runs with a shallow draft, due to the lack of the necessary conditions.

[0015] However, if the ship is fully loaded and traveling at the speed for which it was specifically designed for use in scheduled service – i.e., if all conditions are met for the water displaced under the ship to reappear under the stern at the right moment – ​​then the energy-saving potential is immense!

[0016] The potential of this wave-riding ship hull with its pointed-arch trailing edge is not limited to the recuperation of a significant portion of the propulsion energy used. As a consequence of its shape, wave resistance is also reduced to virtually zero. This means that a bow wave, which is unavoidable on today's conventionally hulled giant ships at full speed in the ocean, is no longer noticeable on the wave-riding ship hull with its pointed-arch trailing edge.Because the water displaced in the bow area of ​​this type of vessel is channeled completely beneath the ship, a bow / displacement wave resulting from displacement "to the left and right" cannot even form in the first place. This, of course, directly leads to the advantageous effect that the engine power of such a vessel with a novel hull design can be reduced. This measure then automatically results in a significant reduction in fuel consumption. The potential of the invention—with regard to reducing the wave resistance of such a hull design—thus entails a whole chain of positive effects. Naturally, the flow turbulence that naturally occurs downwind of the trailing edge of such a wave-riding hull according to claims 1-10 leads to a slight increase in form drag.

[0017] However, this is more than compensated for many times over by the recuperation yield that now occurs as a result of the thrust vector created by the upward-pressing water in the area of ​​the rear, ascending ramp of the invention. A particular advantage of the wave-riding ship hull according to the invention: its wetted surface area is no larger than that of ships with a conventionally shaped hull.

[0018] Since the amount of wetted surface area of ​​a ship's hull is crucial for the resistance it experiences when moving through the water, it is essential to keep this wetted surface area as low as possible. Therefore, for a new design to be successful, it must not significantly exceed the level achieved by, for example, "conventional hulls," which essentially operate on the dugout canoe principle. A particular advantage of this new design, distinguished by its pointed-arch trailing edge, lies in the fact that, despite the completely redesigned, novel hull shape, the amount of wetted surface area does not increase, not even by a single centimeter. 2(compared to ship hulls with a conventionally shaped bow). In other words: the level of resistance that conventionally shaped ship hulls exhibit with regard to the impact of their wetted surface, and which must be used as a benchmark, does not increase in the new design, which is equipped with a trailing edge in the form of a Gothic arch! Not in the slightest.

[0019] For the concave hollow shape / the inverted bow of the new ship, which appears at the front of the underwater hull of the new vessel as a result of the now existing sill, in the form of a Gothic arch, is in terms of surface area nothing other than a "normal ship's hull", even if the whole thing is of course reversed inwards, i.e., this "negative image" of a conventional, traditional ship's bow does not in any way require "more" of "wetted surface" than the "positive version" of previous ship types.

[0020] The surface area in the midship and stern sections of the invention (i.e., in the sector with the horizontal hull bottom and in the area of ​​the aft, rising ramp) is at least equivalent to, if not slightly better than, conventionally shaped ship hulls with regard to the criterion of "wet surface area." This is because there is no "narrowing of the hull" in the area of ​​the aft, rising ramp, as is the case with conventionally shaped ship hulls—since the rising ramp extends across its full width to the water's surface in order to achieve the optimal possible recuperation result (as every centimeter 2 (a "sloping bottom" in the stern area of ​​the inventive ship's hull, which is subjected to an upward flow and thus generates additional thrust for the ship through recuperation, is included!)

[0021] In summary, the following can be stated: Due to its special shape, the hull shape according to the invention enables the recuperation of drive energy to a significant extent - without this having to be bought at the cost of an increase in wetted surface area, i.e. increased water friction of such a ship hull shape. A particular advantage of the innovative wave-riding ship hull: centering of the flow that is displaced under the ship.

[0022] The pointed arch of the breakover sill advantageously ensures that the water flowing towards the ship from the front is initially forced downwards and, upon reaching the apex of this arch, is further concentrated, automatically increasing its flow velocity. This higher velocity of the water flow descending beneath the ship then results in the water reaching a greater depth (where higher water pressure prevails). When this water subsequently resurfaces beneath the stern, the greater pressure difference overcome results in a higher energy impulse that this water can transfer to the aft, upward-leading ramp (compared to if it had simply been forced upwards from a shallow area).

[0023] The pointed arch shape of the rupture edge is therefore directly and fundamentally responsible for the particularly high energy recovery capacity achievable with ship hulls designed in this way. Of course, other rupture edge shapes would also be conceivable, for example, a U-shape or a parabolic shape – but the pointed arch design is the most advantageous and effective of all. A particular advantage of the innovative wave-riding ship hull: The acceleration of the water flow occurs over a long distance.

[0024] Although the inverted bow (which forms a pointed arch as a result of the shape of the trailing edge) both concentrates the water flow and accelerates it far downwards, under the ship (as just described in the paragraph above), this acceleration process itself is advantageously not abrupt but rather subtle, since it takes place over a relatively long distance (because the concave hollow shape of the inverted, turned-up bow of the new ship extends far towards the midship).

[0025] Compared to the previous version (the utility model with registration number AZ 10.2022 002 819, which was characterized by a dredge-scoop-like water flow feeder leading directly to the straight breakover sill near the bow), this new, significantly slower acceleration of the descending water flow represents a substantial reduction in the energy required to force the water displaced by the ship beneath its hull. Lower energy consumption translates to reduced resistance—and therefore reduced fuel consumption for the engine, meaning lower fuel costs. A particular advantage of the new wave-riding ship hull: a relatively long sector with a horizontal ship bottom.

[0026] A key element of wave-riding ship hulls, which are characterized in particular by their ability to recuperate propulsion energy, are the two ramps at the bow and stern, which first direct the water flow downwards and then upwards again. Logically, the ship's bottom is not horizontal in the area of ​​these two ramps, but angled – which seems less than ideal in terms of maximizing hull loading capacity. For container ships, the ideal loading point is always the longest possible horizontal section of the hull, i.e., the simple trough shape, as this allows for the maximum number of containers to be stowed within the hull.However, even conventionally shaped ship hulls (which, unlike wave-riding hulls, do not offer energy recuperation) exhibit significant constrictions at their bow and stern. In other words, the loss of cargo space resulting from choosing a wave-riding hull shape is rather marginal, or even negligible. In the area of ​​the aft ramp, a wave-riding hull shape might even result in a gain in cargo volume: because the aft ramp should have a rectangular cross-section across its entire underwater area (up to the waterline) to achieve optimal recuperation properties, there should actually be an increase in container cargo volume compared to the stern section of conventionally shaped ship hulls. A particular advantage of the new wave-riding ship hull: the bow area at the level of the trailing edge can be ideally used as a tank space.

[0027] The bow section of a new type of wave-riding ship hull – which features a pointed-arch trailing edge – is, due to the concave hollow shape of its downward-leading ramp, "too fragmented" and often too narrow within the hull to be used as storage space for containers. However, this is not a disadvantage in itself, as the hull volume of this section offers an ideal area for storing the liquid fuel for the ship's diesel engine. While today's container ships are still almost exclusively powered by heavy fuel oil (essentially waste products from petroleum refining, i.e., fossil hydrocarbons, the combustion of which is extremely environmentally damaging), the future of container shipping will be based on sustainably produced fuels such as "green" methanol.Methanol generally has a slightly lower calorific value than the previous, "environmentally harmful fuels," meaning that ships powered by methanol inevitably require a somewhat larger tank volume than conventional designs. The bow area of ​​an innovative, new wave-riding ship hull is ideally suited for this, as it can easily accommodate large quantities of this environmentally friendly fuel, known as "green methanol." A particular advantage of the new wave-riding ship hull: A bulbous bow in front of each of the two skirts can be used as volume for ship trimming.

[0028] For a wave-riding vessel hull according to the invention, it is important that the hull is always correctly balanced in the water in order to actually achieve the maximum possible recuperation performance. A "sagging" stern or a "buoyant" bow would logically be detrimental to this goal. Of course, efforts are made to keep the vessel "upright" even during loading, but the consumption of fuel during the voyage from a tank not located at the vessel's center of gravity can, under certain circumstances, lead to a slight list during an overseas crossing. To prevent this, it is advantageous to position a bulbous bow in front of each of the two leading edges of the bow's protruding skirts, the interior of which can be flooded to provide a corresponding correction capability for the vessel's position in the water.Because volumes at this position – being at maximum distance from the center of gravity – have the best leverage, which is why the trimming requirements of this type of ship can be met most easily and simply. A particular advantage of the new wave-riding ship hull: its above-water section – including the bow – is identical to conventional designs.

[0029] In a ship equipped with a wave-riding hull according to the invention, featuring a trailing edge in the form of a pointed arch, all changes compared to ships with a conventionally designed hull are limited to the underwater section. Therefore, when a ship constructed according to the invention is fully loaded in the water, it cannot be immediately distinguished from other ships built in the traditional, conventional style when viewed from the outside.

[0030] For example, the above-water bow of the invention is designed in a traditional, classic manner (i.e., 'plow-shaped'), thus it can advantageously continue to 'differ' incoming breakers laterally to the left and right in such a way as to avoid damage to the ship - and even in the event of an encounter / collision with an unwary small vessel (e.g., a yacht or a small motorboat), this weaker part is more or less gently pushed aside by the - conventionally designed - above-water bow of the invention, so that the "smaller" vessel at least has a real chance of surviving this encounter.

[0031] However, should a vessel designed according to the invention undertake an empty voyage across the oceans (which, experience shows, is extremely rare), during which its underwater hull would inevitably protrude far out of the water, a collision with a miniature vessel would be fatal. This is because the skirts to the left and right of the forward ramp at the bow would then be largely exposed. An unwary miniature vessel that were to enter this "maw" would have no chance of survival; the tiny vessel would be crushed, literally swallowed up, and forced down beneath the inventive vessel – thus ending up as a total loss with presumably the entire crew perished.

[0032] Apart from such exceptional situations, the invention, as mentioned, results in no change above the waterline compared to conventionally designed ocean liners when the ship is loaded, meaning that the novelty is advantageously fully compatible with the existing infrastructure of global shipping (waterway depths, ports, tugboat operations, etc.).

[0033] Even though the external appearance of the invention is normally so unspectacular – i.e., when fully loaded and submerged – that it is hardly possible to distinguish a conventionally shaped ship from a novel ship designed according to the invention, there is one criterion that undoubtedly reveals the fundamental difference between the two construction concepts: A novel wave-riding ship hull with a breakaway sill in the form of a Gothic arch does not produce a bow wave, even at full speed! While today, when flying over the ocean, one can easily spot large ships (with conventionally designed hulls) from many kilometers away by the bow wave that emanates from them – and spreads out over a wide area behind them – in the future, the opposite will likely be observed.Giant ships equipped with a novel, inventive wave-riding hull featuring a pointed-arch trailing edge will be detectable by the trail of completely still water they leave in the sea. At the bow, the wave-filled sea will disappear between the skirts of such a hull and emerge at the stern as a smooth, flat band – that is, as a still surface of water. This completely unfamiliar sight heralds a true turning point in shipping, the beginning of a new era in which the transport of goods on the world's oceans will be significantly more economical than it is today.

[0034] The invention is explained in more detail below with reference to an exemplary embodiment and to drawings 1 to 10. The drawings show: Drawing 1: The perspective view of a wave-riding ship hull according to the invention with a breakaway sill in the form of a pointed bow in a view from obliquely below, with the numerical designation of its individual components. Drawings 2 & 3: Two different ship hulls as side views for comparison - the upper illustration shows a ship with a conventional hull - and the lower illustration visualizes the shape of a novel wave-riding ship hull with a trailing edge in the form of a pointed bow. Drawing 4: The schematic representation of the flow pattern that occurs "from bow to stern" in the invention, in a view from below / onto the ship's bottom. Drawing 5: The perspective view of a wave-riding ship hull according to the invention with a breakaway edge sill in the form of a pointed arch, viewed from a side view from below, with particular reference to the pressure exerted on deep water layers far below the ship. Drawing 6: Illustration of the flow pattern in the area of ​​the 'dead water zone' / eddy zone (the zone directly following the breakover weir in detail) Drawing 7: The perspective view of a wave-riding ship hull according to the invention with a break-off edge sill in the form of a pointed arch with special consideration of the distance “D” (the sector with horizontal ship bottom between front and rear ramp) Drawing 8: The perspective view of a wave-riding ship hull according to the invention with a trailing edge sill in the form of a pointed arch in the view angle of a front view / from obliquely below - with a bulbous bow in front of each of the two skirt leading edges. Drawings 9 and 10: The perspective views of two wave-riding ship hulls according to the invention with trailing edge sills in the form of pointed arches, which are equipped with nozzle ring propellers (drawing 9) and pod drives (drawing 10).

[0035] In drawing 1, a perspective view from a low angle shows a "wave-riding ship hull with a breakaway edge in the form of a pointed arch" according to the invention, the essential innovation of which is precisely this breakaway edge in the form of a pointed arch (1). It ensures that the water flowing towards the bow when the ship is moving forward, and which has previously been accelerated downwards as a water stream from a forward ramp (2) (designed as a concave hollow shape), detaches from the hull and dives far below the ship. The two skirt extensions (3), which project vertically downwards as edges at the beginning of the hull sides on the left and right, are responsible for the fact that the water at the bow could be captured and shaped into a water stream, which could then be forced downwards below the ship.Above the waterline (4), the bow of the invention has a completely conventional, plow-shaped form – comparable to the usual shape of a standard bow on modern ocean liners. The midsection of the invention is characterized by a sector with a horizontal hull bottom (5), under which the water flow forced beneath the ship reaches its maximum depth (and thus its maximum pressure). Immediately following this, the area of ​​the ascending, aft ramp (6) begins, where the recuperation of the propulsion energy, previously invested in the bow area, occurs from the movement of the upward-moving water flow – which is seeking pressure equalization. The distance “D” (7) between the forward and aft ramps significantly determines the effectiveness with which the recuperation of the propulsion energy of the invention can take place.By installing a bulbous bow (8) on each side as a projection of the side skirts, volumes can be generated under the bow, which, in this position far from the center of gravity, can be very effectively used as trim tanks to change the buoyancy in the bow area. A propulsion system under the stern of the ship, which is either based on jet-ring propellers (9) or alternatively can consist of propeller pods (10) (also known as pod drives), provides propulsion for the invention on the world's oceans.

[0036] Drawings 2 and 3 show two different ship hulls in side views, both being of the same type of cargo ship, namely container ships, to ensure a fair comparison. This superimposition makes it very easy to understand the differences between a ship with a conventional hull (shown in the upper illustration, drawing 2) and the new wave-riding hull with a pointed arch-shaped trailing edge (shown in the lower illustration, see drawing 3).

[0037] Above water, there are virtually no discernible differences between a conventionally designed hull and a wave-riding hull according to the invention. However, when comparing the two ship shapes below the waterline, the formal differences are significant.

[0038] While the ship shown in drawing 2 with a hull in normal design has a continuously straight keel line, thus having the maximum draft "from bow to stern" and can therefore fully exploit the ideal container loading capacity in the underwater hull area, the wave-riding ship hull (drawing 3) naturally loses some loading capacity due to its 2 ramps (at the bow and at the stern) - see the course of the two ramps: the course of the front ramp is visualized by the dashed line, the rear ramp rises continuously from the midship sector (with horizontal hull bottom) to the stern of the ship.Nevertheless, this loss of cargo capacity in the new design (compared to a hull of 'normal' design) remains within acceptable limits, because even the conventionally shaped hull has pronounced constrictions at the bow and stern to cut through the water as efficiently as possible – which naturally reduces capacity in the bow and stern. The fact that the slightly lower cargo capacity of a wave-riding ship hull according to the invention in the hull area below the waterline is not actually all that significant would be immediately apparent if the complete container loads had been included in the two illustrations, which, as is well known, are stacked up to the level of the bridge on fully loaded ships. In other words, the majority of the containers are stowed in the hull areas above the waterline in both hull types, and, moreover, naturally "in the open" from the deck line upwards.These are zones where there are hardly any differences between the two ship types shown in the illustrations. And even if a wave-riding hull according to the invention ultimately "falls short" in terms of loading capacity compared to a "conventional boom hull," this is not a significant disadvantage. A container ship equipped with a wave-riding hull according to the invention is considerably less resistant on the world's oceans and therefore more economical than a ship with a conventionally shaped hull – and can thus demonstrate such a significant reduction in fuel consumption during operation (a savings potential of 30% can be assumed) – that the economic calculation ultimately favors the invention so clearly that a container ship with a conventionally shaped hull is commercially "simply lagging behind."

[0039] Drawing 4 shows a bottom view of a wave-riding ship hull according to the invention, with a leading edge sill in the form of a pointed arch. The drawing also illustrates the course of the water flow as it naturally results from the shape of the underwater hull of this type (see arrow symbols). The water flowing towards the bow is captured by the skirt attachments on the left and right and accelerated downwards by the forward ramp, which is designed as a concave hollow. This results in an increase in the pressure of the water mass. After passing the edge of the sill (which is also in the form of a pointed arch and represents the location of the highest flow velocity, symbolized graphically by the increasingly dense hatching of the arrow symbol), the water experiences a further increase in pressure as it descends below the midships.After reaching the turning point / lowest level to which this water flow is forced beneath the ship / which thus represents the point of extreme position (the speed of the water mass drops to 0 – simultaneously, its pressure level reaches its maximum), the ascent – ​​in the area of ​​the rear, rising ramp – results in a pressure reduction and a simultaneous slowing of the flow velocity (→ graphically symbolized by the decreasing line density of the hatching of the arrow symbol) – while transferring kinetic energy to the stern of the inventive wave-riding ship hull = propulsion. The general principle underlying an inventive wave-riding ship hull according to claims 1 to 10 is particularly clearly illustrated in this diagram – with the help of the additionally superimposed arrow symbol.The entire process functions like a water conveyor belt beneath the ship, generating a standing wave on which the inventive wave-riding ship hull glides forward like a surfer. However, the most important message of this illustration is this: The water flowing towards the hull of such a wave-riding ship hull is guided completely beneath the ship, remains completely under the ship as it travels aft, beneath the midsection, and finally rises completely under the rear ramp back to the water's surface – without any guidance from skirts or other control devices. This means that the recuperation of propulsion energy is "total," nearly 100%.

[0040] In drawing 5, a perspective side view from below shows a wave-riding ship hull according to the invention with a trailing edge sill in the form of a pointed arch, including the expected pressure line profile under the ship as it develops in intercontinental traffic at "normal service speed". The highest pressure level is reached in the area below the horizontal, 60-meter-wide hull bottom. The water displacement of the water flow into the depths, triggered by the novel hull, has an effect even far below the ship. Even at depths of 60 to 100 meters, the water pressure increases noticeably – only then do the isobars flatten out due to the counterforce – the increasing water pressure in the deeper layers.Since water is incompressible, the entire space beneath the ship acts like a kind of resonating chamber (whereby the pressure increase beneath the ship in this upwardly open system – see the water surface with the subsequent "air overlay" – always results in a slight lifting of the entire water surface around the ship). The water then naturally tries to escape this temporary pressure surge beneath the ship as quickly as possible, striving to achieve the fastest possible pressure equalization – taking the first available escape route towards the water's surface.This is solely due to the ascent under the upward-leading, rear ramp, beneath which a space constantly opens up as a result of the ship's forward movement, allowing the deep water to "flood" in – thus propelling the ship forward (→ because the pressurized water under the ship cannot reach the – admittedly shorter – paths directly to the left and right of the ship, as the upward-moving water is "moving water" – which (according to Bernoulli's principle formulated in 1783) automatically always has a lower pressure level than the (at the same level) "still water" to the left and right of the ship. And since the moving water could never overcome the pressure level to the left and right, i.e., could never displace this water, the only escape route remains under the stern of the ship. Therefore, the installation of skirts for water channeling under the stern is unnecessary.The water pushes upwards "as if on rails", flanked by surrounding water of higher pressure.

[0041] The shape of the rear, upward-leading ramp can be straight "like a board" (container cargo space optimized) as in the illustration shown here, but can also take on a bell shape - i.e., optimized for the most effective form of water release / pressure reduction.

[0042] Figure 6 illustrates the flow pattern in the eddy / dead zone – the area directly adjacent to the sill. Because the water in the underflowing stream detaches from the hull at the sill, an eddy inevitably forms, where the water flows against the general current. In this zone, some of the water flows "from back to front" instead of "from bow to stern" (although, strictly speaking, it is the hull that moves within the water, while the seawater is a stationary fluid, meaning the eddy "clings" to the hull). This energy-intensive eddy is the price to pay for the virtually unobstructed flow of water deep beneath the ship.Since the proportion of this eddy current is relatively small in relation to the total flow volume, the losses arising here are not significant – they are negligible in view of the immense energy recuperation power generated by the upward-moving water current under the stern, which pushes the wave-riding ship hull according to the invention forward – in the direction of travel.

[0043] Drawing 7 shows a wave-riding ship hull according to the invention and claims 1 to 10 in a perspective view from below, in which particular emphasis is placed on the significance of the distance "D". It is clearly visible that this distance "D" begins at the endpoint of the forward ramp (at its tip / where the trailing edge threshold extends furthest into the sector with the horizontal hull bottom) and ends where the aft, upward-leading ramp begins. This end of distance "D" could also be described as the inflection point of the ship's bottom, from which the sector of the aft, upward-leading ramp begins.

[0044] Drawing 8 shows – in a perspective view from the front and from a low angle – a wave-riding ship hull according to the invention with a trailing edge sill in the form of a pointed arch, which is equipped with a bulbous bow in front of each of the two leading edges of the skirts. These bulbous bow extensions appear as streamlined volumes located far from the center of gravity, which have the potential to influence the trim of the ship (by means of floodable ballast water tanks), thereby having a ship-stabilizing effect.

[0045] In drawings 9 and 10, two wave-riding ship hulls according to the invention are shown in perspective views. These hulls feature sills shaped like Gothic arches and are equipped with two different propulsion options. The upper drawing shows a hull with two pod drives, while the lower drawing shows an alternative configuration with two nozzle ring propellers. Both propulsion options are rotatably mounted, thus largely eliminating the need for conventional rudders (only the profiled support structure of the drives acts as a small, conventionally effective rudder surface). Compared to the conventional installation where ship rudders are downstream of the propellers, this measure significantly reduces the control surfaces and, consequently, the induced drag they generate. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2022 002 819

[0001] DE 202013 004 518.3

[0003] WO 20 2013 004 518.3

[0004] DE 10 2021 004 029.5

[0005]

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