Method of manufacturing a rotor body of a Magnus-type rotor
10099762 · 2018-10-16
Assignee
Inventors
Cpc classification
Y02T70/5236
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
Abstract
A method is provided for manufacturing a rotor body of a Magnus-type rotor. The method includes providing a plurality of arcuate panels, wherein each of the panels has an arc-length less than a predetermined circumference of the rotor body. The method further includes positioning at least three such arcuate panels in mutual edge-wise abutment to form circumferentially a hollow cylindrical loop, wherein longitudinal edges of adjacent panels are mutually attached to each other. The method further optionally includes co-axially stacking one above another at least two loops of substantially similar diameter. The method further includes connecting edges of adjacent loops to define the rotor body of a predetermined height.
Claims
1. A method of manufacturing a rotor body of a Magnus-type rotor, wherein the method comprises: forming each of a plurality of hollow cylindrical loops by: (i) providing at least three arcuate panels made of at least one self-carrying composite material having a multilayer structure of a sandwich design including a core material and a balancing member within the multilayer structure, wherein each panel has an arc-length less than a circumference of the rotor body of the Magnus-type rotor; (ii) positioning the at least three arcuate panels in mutual abutment at two opposing edges of each arcuate panel; (iii) connecting the at least three arcuate panels together by attaching the opposing edges of adjacent arcuate panels to each other, to form circumferentially an individual hollow cylindrical loop usable as a part of the rotor body of the Magnus-type rotor; and (iv) circumferentially balancing a weight of the individual hollow cylindrical loop.
2. A method as claimed in claim 1, wherein the method further comprises: stacking, co-axially one above another, the plurality of hollow cylindrical loops; and connecting the edges of adjacent loops to define the rotor body of the Magnus-type rotor.
3. The method as claimed in claim 2, wherein a height of the arcuate panels is less than a height of the rotor body.
4. The method as claimed in claim 1, wherein the at least one self-carrying composite material is selected from the group consisting of fiberglass reinforced plastics materials, carbon reinforced plastics materials, glass reinforced plastics materials, aramid reinforced plastics materials, basalt reinforced plastics materials and combinations thereof.
5. The method as claimed in claim 1, wherein the arcuate panels are manufactured by using a resin infusion process.
6. The method as claimed in claim 1, wherein the edges of adjacent panels are attached to each other by employing at least one of an adhesion process, an over-lamination process, and a fastening mechanism.
7. The method as claimed in claim 2, wherein the edges of adjacent loops are attached to each other by employing at least one of an adhesion process, an over-lamination process, and a fastening mechanism.
8. The method as claimed in claim 6, wherein the fastening mechanism comprises at least one of adhesive fasteners, bolts, rivets, pins, and screws.
9. The method as claimed in claim 1, wherein the arcuate panels of one loop have similar mass properties.
10. The method as claimed in claim 2, wherein the method further includes counter-rotating adjacently positioned loops to offset the longitudinal edges of the panels in the co-axially stacked loops.
11. A Magnus-type rotor (108), comprising a support tower (118) and a rotor body (114), wherein the rotor body (114) comprises at least a plurality of hollow cylindrical loops, each comprising at least three arcuate panels (402, 802) made of at least one self-carrying composite material having a multilayer structure of a sandwich design including a core material and a balancing member within the multilayer structure, wherein each Panel has an arc-length (W) less than a circumference (C) of the rotor body, the arcuate panels being attached to each other at two opposing edges (406, 806) of each arcuate panel, to form circumferentially an individual hollow cylindrical loop (404) forming a part of the rotor body, wherein a weight of the individual hollow cylindrical loop has been circumferentially balanced.
12. The Magnus type rotor as claimed in claim 11, wherein the plurality of hollow cylindrical loops (404) are stacked co-axially one above another and connected to each other, each loop comprising at least three arcuate panels (402).
13. The Magnus type rotor as claimed in claim 12, wherein the opposing longitudinal edges (406) of the arcuate panels (402) in the co-axially stacked loops (404) are offset one from another.
14. The Magnus type rotor as claimed in claim 11, wherein an inner surface (114a) of the rotor body (114) is affixed with one or more further balancing members (506), wherein a location of each further balancing member is selected based upon an overall spatial weight distribution across the circumference (C) of the rotor body.
15. The Magnus type rotor as claimed in claim 11, wherein a height (H) of the rotor body (114) is more than a height (L) of the support tower (118).
16. The Magnus-type rotor as claimed in claim 15, wherein the support tower (118) is configured to support pivotally the rotor body (114) at more than 50% of the height (H) of the rotor body.
17. A nautical vessel (100) comprising at least one Magnus-type rotor (108) according to claim 13.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating embodiments of the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
(2) Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12) In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE DISCLOSURE
(13) The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although the best mode of carrying out the present disclosure has been disclosed, those in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
(14) In one aspect, embodiments of the present disclosure concern a method of manufacturing a rotor body of a Magnus-type rotor, the method comprising (i) providing at least three arcuate panels having a multilayer structure, wherein each panel has an arc-length less than a circumference of the rotor body of the Magnus-type rotor; (ii) positioning the at least three arcuate panels in mutual abutment at two opposing edges of each arcuate panel; and (iii) connecting the at least three arcuate panels together by attaching the opposing edges of adjacent arcuate panels to each other, to form circumferentially a hollow cylindrical loop usable as at least a part of the rotor body of the Magnus-type rotor.
(15) In the present invention, by the opposing edges of the arcuate panels are meant the sides (of which each panel typically has four) that would be opposing each other if the panels were flat, i.e. side edges or the edges at the top and bottom of the panel. The opposing edges are furthermore those sides that will be along the longitudinal direction of the rotor body, once it is finished. The longitudinal direction is also the direction of the axis of the rotor body. Indeed, the rotor body has a circumference and a length, wherein the length is typically significantly larger than the circumference. The length corresponds to the height of the rotor body when it is in its normal operating position, i.e. upright.
(16) In another aspect, embodiments of the present disclosure pertain to a method that comprises (iv) forming at least one further hollow cylindrical loop of substantially similar diameter by positioning and connecting to each other at least three further arcuate panels; (v) stacking, co-axially one above another, the at least two hollow cylindrical loops; and (vi) connecting the edges of adjacent loops to define the rotor body of the Magnus-type rotor.
(17) The rotor body may thus be made of one hollow cylindrical loop, wherein the length (height) of each arcuate panel is equal to the length (height) of the finished rotor body, or it may be made of more than one hollow cylindrical loop arranged coaxially one on top of another. It may be made of for example two, three, four, five, six, seven, eight, nine, ten or more cylindrical loops. Each loop may also be made of more than three arcuate panels, and not all loops need to have the same number of arcuate panels or the same length (height). Indeed, additionally, the method also includes providing the arcuate panels with a height which is less than the (predetermined) height of the rotor body. Optionally, the method also includes providing the arcuate panels with a height equal to the predetermined height of the rotor body.
(18) It would also be possible to manufacture the rotor body by firstly attaching arcuate panels to each other to form an element having the length of the finished rotor body, and to then attach thereto another (one or more) element having also the length of the finished body, i.e. to form a hollow cylindrical loop after stacking arcuate panels on top of one another.
(19) Moreover, the arcuate panels may be formed by employing a resin infusion process. However, it will be appreciated that other approaches to manufacturing the arcuate panels are feasible, pursuant to the present disclosure; for example, prepreg, namely pre-impregnated but not fully hardened composite material, is optionally employed when manufacturing the arcuate panels. According to another embodiment, the panels are manufactured from at least one self-carrying composite material. The self-carrying composite material is optionally selected from one or more of: fiberglass reinforced plastics materials (FRP), carbon reinforced plastics materials (CRP), glass reinforced plastics materials (GRP), aramid reinforced plastics materials, basalt reinforced plastics materials and combinations thereof. However, other types of materials are optionally or additionally employed in lieu of the self-carrying composite materials, for example high-strength ceramics materials, nano-fibres and similar. Moreover, various lightweight materials such as, but not limited to, ship building materials can be used in lieu of the self-carrying composites mentioned above. Optionally, the composite materials employed are implemented as a sandwich design, including a core material. The core material, for example, includes one or more of: polyvinylchloride foam, polyethylene foam, polystyrene foam, balsa wood, syntactic foams, honeycomb-like structures. Moreover, in respect of manufacturing the arcuate panels, a self-carrying composite employed in their manufacture optionally means a multilayer structure, for example a sandwich-like structure devoid of a need for a separate load-carrying and load-transmitting structure.
(20) Moreover, the longitudinal, opposing edges of adjacent panels are mutually attached to each other by using one or more of: an adhesion process, an over-lamination process, and a fastening mechanism, wherein the fastening mechanism optionally includes at least one of adhesive fasteners, bolts, rivets, pins, and screws. The edges of adjacent loops may also be attached to each other using one of these techniques.
(21) Additionally, the method further includes balancing a weight of the rotor body across the circumference thereof. Optionally, a weight of each loop is individually balanced across its circumference. Alternatively, the step of positioning at least three arcuate panels in edge-wise abutment optionally includes using at least three arcuate panels of substantially similar mass properties therein, i.e. the arcuate panels of one loop have substantially similar or identical mass properties. Moreover, an inner surface of the rotor body is optionally affixed with one or more balancing members, wherein each balancing member is optionally located based on an overall weight distribution across the circumference of the rotor body.
(22) Indeed, the panels may themselves has different weights, either slightly due to the manufacturing technique, or a greater difference due to significant variations in size. However, it is necessary for the rotor body to have a well balanced weight, as during use, it is subjected to strong centrifugal forces, which will cause any heavier areas to extend towards the outside of the rotor body, hence deforming its shape. Moreover, in some embodiments, the joint area is heavier than the panel material (due to additional material or attachment means) and this would cause the heavier areas to extend outside under fast rotation. For compensating this, one or more balancing members are located between the longitudinal edges of the segment. This evens the circumferential mass distribution and is hence beneficial for maintaining the roundness of the cross section as accurately as possible under very fast rotation. Minimizing the out-of-roundness also results in a better lift coefficient for the finished device. As the lift coefficient influences the total efficiency of the Magnus rotor, its optimising has a significant impact on the rotor. It is also to be noted that the fact that the joints that are circumferential (i.e. the joints between two loops stacke on top of each otehr) are also slightly heavier than the arcuate panels, does not have an influence on the roundness of the cross section, as they extend over the whole cross section.
(23) According to an embodiment, a balancing member is arranged approximately in the middle of each arcuate panel. By middle, it is here understood the middle of the panel between the two opposing, longitudinal edges, i.e. the edges used for attacing the panel to the other panels for forming the loop. Hence, for example for a loop made of three arcuate panels, there are six heavier sections in the loop, i.e. the three joint areas between the panels and the three balancing members in the middle of each panel. Thus the roundness of the loop is better maintained during using of the device. In a loop made of four arcuate panels, there would be preferably eight such heavier sections and the roundness would be even better maintained.
(24) The balancing members may also be of two different types, namely balancing members designated to balance the difference of weight of the joints between the panels and balancing members designated to balance the overall structure, i.e. difference of weight due to manufacturing process or other structural aspects. The first type of balancing members (which may also be called joint balancing members) can be incorporated into the arcuate panels already during their manufacture, for example as a an additional strip of material in the layered structure. The second type of balancing members (which may also be called mass balancing members) are typically added during the balancing process, i.e. testing of the loop or the finished rotor body, and hence their location in the loop and thus rotor body varies from one loop to another. As mentioned, balancing each individual loop is preferred as it is significantly easier and hence cheaper to perform.
(25) It has been noted that balancing each loop individually offers significant advantages over balancing the finished rotor body. Indeed, it is usually sufficient to balance each loop and hence balancing of the finished rotor body is no longer required. Considering that the finished rotor body can have a diameter of up to 5 meters and a height of up to 30 meters, whereas one loop can have a height of for example only 3 meters, this is a clear advantage in the manufacturing process. Moreover, even if the finished rotor body still needs balancing, it is made considerably easier as a major part of the imbalances have already been corrected.
(26) According to another embodiment, in case of loops being stacked, adjacent loops are counter-rotated to offset the longitudinal edges of the panels in the stacked loops. According to a preferred embodiment, each loop is first individually balanced and only thereafter stacked. Some advantages in using multilayer structures arcuate panels in smaller sections as in the present description are an easier control of shrinkage of the panels during the manufacture. Indeed, the relative shrinkage of the smaller segmented parts is less than if the loops were made in only two parts (i.e. two halves) and therefore the out-of-roundness of the outer surface is better controlled. Further, the resin flow during a resin infusion process (if used) is easier to control, as the smaller arcuate panels, in which the cross-section height is less than in a full or halved model, have more accurate resin flow in the vacuum resin infusion than components having larger vertical distance between the lower and upper ends. This enables more equal resin distribution and hence also mass distribution in the finished arcuate panels. A yet further advantage is that when the arcuate panels are made in a smaller scale, the molds are smaller and the lay-up process can be more accurate and faster. Indeed, no jigs or fixtures are needed. Another advantage is that the process requires only common tools, which are relative cheap and easy to obtain.
(27) A yet further advantage of smaller arcuate panels is that each segment can be weighed separately and mated with other segments with corresponding properties in an easier manner than if large panels are used. Another advantage of this production method relates to supply chain management, as the manufacture of the arcuate panels (and optionally their assembly to form the rotor body) and the manufacture of the rotor itself can be done different places. Hence it is typically easier to find production facilities and staff. A yet further advantage is that the arcuate panels can be manufactured at one site and the actual assembly in another, as the panels are easier to transport than the whole rotor body. For example, the panels can be manufactures centrally in one or two locations and the assembly done close to shipyards. It is also possible to manufacture the panels and the small loops at one location and stacking of the loops to form the rotor body in another location.
(28) Moreover, in an aspect, there is provided a rotor body manufactured using the methods disclosed herein, i.e. obtainable by a method according to this description. Furthermore, there are also provided Magnus-type rotors including a support tower, and employing the rotor manufactured using the methods of the present disclosure. Moreover, it is also disclosed that, for a given Magnus-type rotor, the predetermined height of the rotor body is more than a height of the support tower, and in which the support tower is optionally configured to support the rotor body at more than 50% of the height of the rotor body.
(29) The present description yet further relates to a Magnus-type rotor, comprising a support tower and a rotor body, wherein the rotor body comprises at least three arcuate panels having a multilayer structure, wherein each panel has an arc-length less than a circumference of the rotor body, the arcuate panels being attached to each other at two opposing edges of each arcuate panel, to form circumferentially a hollow cylindrical loop forming at least a part of the rotor body. According to an embodiment, the rotor body comprises at least two hollow cylindrical loops stacked co-axially one above another and connected to each other, each loop comprising at least three arcuate panels. According to yet another embodiment, the longitudinal edges of the arcuate panels in the co-axially stacked loops are offset one from another.
(30) Moreover, embodiments of the present disclosure are suitable for aquatic vessels such as, but not limited to, passenger ships, cargo ships, ferries, special-purpose ships, naval vessels and boats. The present disclosure thus also relates to a nautical vessel comprising at least one Magnus-type rotor according to this description.
(31) Referring now to the drawings, particularly by their reference numbers,
(32) The propulsion system 102 also includes a plurality of Magnus-type rotors, depicted as a Magnus-type rotor 108a, and a Magnus-type rotor 108b, hereinafter collectively referred to as Magnus-type rotors 108. The Magnus-type rotors 108 are beneficially spatially positioned at various regions of a deck 110 of the aquatic vessel 100. For example, the Magnus-type rotors 108 are optionally spatially positioned in proximities of corners of the deck 110, namely, port and starboard sides of the bow and the stern. Alternatively, the Magnus-type rotors 108 are optionally spatially positioned in proximity of a middle region of the deck 110, the stern, or the bow of the aquatic vessel 100. The Magnus-type rotors 108 are optionally suitably positioned depending on, for example, a number of Magnus-type rotors set up on the deck 110 of the aquatic vessel 100, the size of the Magnus-type rotors 108, and/or a size and/or shape of the aquatic vessel 100. The Figure also shows a foundation 112, a rotor body 114, a hollow region 116 therein and a support tower 118, which are explained in more detail below.
(33) Referring to
(34) The present disclosure is directed towards methods of manufacturing the rotor body 114 of the Magnus-type rotor 108.
(35) In one embodiment, a first method 300, hereinafter simply referred to as the method 300, including associated steps 302 to 308, is provided for manufacturing the rotor body 114 as is explained in more detail in
(36) Referring again to
(37) As shown in
(38) With reference to the method 300 of the present disclosure, in one embodiment as shown in
(39) In a further embodiment, the step 304 of positioning a plurality of arcuate panels 402, for example at least three arcuate panels 402, in edge-wise abutment can include using panels 402 of substantially mutually similar mass properties therein. The term mass properties disclosed herein is to be regarded as the mass distribution in the material of the individual panels 402a, 402b, 402c, and 402d. If the panels 402a, 402b, 402c, and 402d are made to have mutually similar mass properties, then the cylindrical loop 404 formed from such panels 402 is to be regarded as being beneficially imparted with a uniform mass distribution. Consequently, the loop 404 beneficially has an equal weight distribution across its respective circumference C. Explanation pertaining to the advantages resulting from implementation of panels 402 with substantially similar mass properties, namely uniform mass distribution and equal weight distribution, will be provided later herein.
(40) Referring again to
(41) Moreover, at the step 308, the method 300 includes connecting edges 410 of adjacent loops 404a, 404b to define the rotor body of the predetermined height H. With reference to
(42) In an embodiment as shown in
(43) Moreover, the method 300 beneficially includes an optional additional step of balancing a weight of the rotor body 114 across its circumference thereof. Upon forming the rotor body 114, the rotor body 114 is beneficially tested for uneven rotation and/or wobbling. The rotor body 114 is beneficially mounted on a pre-designed balancing rig (not shown) that is configured to rotate the rotor body 114 at varying speeds and detect and/or measure any uneven rotation and/or wobbling of the rotor body 114. If there is a disparity in the spatial weight distribution across the circumference C of the rotor body 114, an inner surface 114a of the rotor body 114 is optionally affixed with one or more balancing members 506 as shown in
(44) Although it is disclosed herein that the entire rotor body 114 is tested at once in its entirety, it is also optionally feasible to test each loop 404a, 404b individually. Accordingly, in an alternative embodiment, the method 300 optionally includes balancing a weight of each loop 404a, 404b individually across its respective circumference C. To that end, once each loop 404a or 404b has been formed from the arcuate panels 402a, 402b, 402c, and 402d, the formed loop 404a or 404b can be tested for any uneven rotation and/or wobbling therein. Therefore, a manufacturer can optionally choose either to check the balance in the individual weights of each formed loop 404a or 404b, or to balance in respect of the cumulative weight of the rotor body 114. Optionally, the manufacturer can perform both checks i.e., for balance in the weight of each formed loop 404a or 404b on an individual basis as well as for balance in the weight of the total rotor body 114.
(45) Referring to
(46) As shown in
(47) Referring again to
(48)
(49) Referring to
(50) It will be appreciated that the steps 302 to 308 of the method 300 and the steps 702 to 704 are only illustrative and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the present disclosure.
(51) Embodiments of the present disclosure can be used for achieving or obtaining various desirable structural characteristics in rotor bodies and/or Magnus-type rotors such as, but not limited to, a low-weight, a high and uniform stiffness, an even mass distribution, an improved rigidity and/or structural integrity. With implementation of various embodiments disclosed herein, the rotor body is not easily deformed or centrifugally displaced from its rotation at varying speeds. Stable operation of the rotor body can also be achieved as the natural frequency or the Eigen frequencies of Eigen modes of the rotor body are kept high in magnitude.
(52) Embodiments of the present disclosure also allow for economical manufacture, assembly, repair, and/or transportation of the arcuate panels. For example, due to their relatively small size, the arcuate panels can be produced by utilizing smaller manufacturing systems and shipped using small compact containers. Moreover, with flexibility to assemble arcuate panels of similar mass properties, the arcuate panels can be produced at multiple locations and thereafter assembled at a ship yard or a suitable facility. Numerous other benefits and/or advantages may be readily apparent to one having skill in the art and such advantages may be applicable to one or more embodiments of the present disclosure. However, such benefits and/or advantages are anticipated as being nominal to the present disclosure and should in no way limit the scope of the present disclosure and the appended claims herein. Moreover, advantages and/or benefits relating to one embodiment of the present disclosure should be construed as similarly relating to other embodiments disclosed herein.
(53) Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as including, comprising, incorporating, have, is used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.
(54) All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counter-clockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the devices and/or methods disclosed herein. Joinder references (e.g., attached, affixed, coupled, connected, hinged, and the like) are to be construed broadly and may include intermediate members between a connection of segments and/or suggest relative movement between segments. As such, joinder references do not necessarily infer that two segments are directly connected and in fixed relation to each other.
(55) Additionally, all numerical terms, such as but not limited to first, second, third, or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any embodiment, variation and/or modification relative to, or over, another embodiment, variation and/or modification.
(56) Similarly, adjectives such as, but not limited to, articulated, modified, or similar, should be construed broadly, and only as nominal, and may not create any limitations, not create any limitations, particularly as to the description, operation, or use unless specifically set forth in the claims.
(57) In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without necessarily departing from the scope of the present disclosure as set forth in the claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting of the present disclosure. Changes in detail or structure may be made without departing from the present disclosure as defined in the appended claims.
(58) While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad present disclosure, and that this present disclosure not be limited to the specific constructions and arrangements shown and described, since various other modifications and/or adaptations may occur to those of skill in the art. It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. It is to be understood some features are shown or described to illustrate the use of the present disclosure in the context of functional segments and such features may be omitted within the scope of the present disclosure and without departing from the spirit of the present disclosure as defined in the appended claims.