JP3049326B2 - Method and apparatus for generating taut ice, especially for model experiments with ships and offshore structures - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for generating taut ice on the surface of a water part, especially for model experiments with ships and offshore structures, and to an apparatus for carrying out this method. .

State of the art During the planning phase, a model of this ship or offshore structure is tested in an ice tank in order to be able to state the icebreaking conditions of the icebreaker or the load of ice on the offshore structure. The ice tank is a coolable model tank for hydraulic model testing when ice is present on the water. The ice in the ice tank, called model ice, then functions as a physical model of natural ice in the sea or inland waters. The properties of the model ice, especially the mechanical properties,
They must be classified according to the model scale.

Natural ice is usually not suitable for model testing in ice tanks because its strength is too great. Accordingly, various methods have been developed for making model ice. For example, it is known to mix dew point lowering chemicals, e.g., salt, urea, or glycol, with the water that makes the model ice, or to add other additives that change properties, such as sugar or detergents, to the frozen water. ing. The taut ice, frozen by removing surface heat in a conventional manner from the doped water, undergoes a temperature regulation process as soon as it has almost reached the desired thickness. This temperature adjustment process serves to adjust and obtain the required mechanical properties on the model scale. Further, it is known to adjust the density of model ice frozen by a conventional method as follows.
That is, it is known to adjust the density of model ice by continuously or periodically blowing small bubbles into the water portion through a finely perforated hose during the freezing process. Bubbles rise and collect on the lower surface of the ice at that time and become trapped by the ice as it grows (Espoo's Ice Symposium, Spencer DS, G., 1990).
W. Timco, Proc. IAHR Vol. II 745-755).

Furthermore, it is known to put small synthetic resin particles having a density of frozen water in the water part. The synthetic resin particles are trapped by the ice formed. The synthetic resin particles form disturbance points in the ice, and the resulting model ice becomes brittle.

Further, generation of model ice by a spraying process is known. DE-A 33 45 648 describes a method for generating tight ice on the surface of water by a spraying process, in particular for testing ship models. In this method, a droplet of water frozen in air is
Tensioned ice is generated by spraying on the surface of water or by spraying on extremely thin tensioned ice that has formed on the surface of water by freezing in a conventional manner. In this case, the process is continued until all or at least a majority of the tight ice thickness is obtained.
Since the spraying takes place in a low indoor atmosphere, the taut ice forms on the upper side.

The taut model ice created on the surface by freezing and removing heat in a conventional manner has a substantially columnar grain structure (FIG. 2). Such a taut model ice freezing process typically involves spraying a fine water mist into cold air above the water in an ice tank that is free of any ice and is ready for freezing. The fog droplets freeze in the air and fall on the water surface as fine ice crystals. Thus, the fog droplets spontaneously form an extremely thin ice film. The c-axis of the ice crystals of this ice film is oriented without adjustment. The c-axis is the main anisotropy axis of the hexagonal crystal lattice structure of ice. Since the growth rate of ice crystals in the direction perpendicular to the c-axis is the highest, the spontaneously formed ice film has a substantially horizontal c-axis than other undesirably oriented crystals. Grows faster.
This is because the direction of the highest growth rate is parallel to the direction of the heat flow. As a result, the grains oriented in the desired direction quickly grow into columns in the water portion and displace away the adjacent undesired grains as they become longer. Thereby, as the depth increases in the horizontal section, the number of grains decreases and the diameter of the grains increases.

In the case of doped frozen water, a thin ice layer is first formed under the ice film formed by the frozen fog. The ice surface is relatively small and is composed of non-columnar or almost columnar ice grains (FIG. 3). The thickness of the surface layer of the fine crystals can be up to about 1 cm depending on the addition of water and the freezing rate, but may not be large. The columnar grains start on the lower surface of this surface layer,
When present, it will reach the underside of the entire taut ice, unless displaced by adjacent grains oriented in the desired manner. The mechanical properties of model ice grown in a columnar shape are planar isotropic. When the columnar-grown and stretched model ice is subjected to a bending load, that is, a load of a typical type during ice breaking by a ship, cracks are preferably formed along grain boundaries of the columnar grains (FIG. 4). That is, in a vertical section of tight ice, transverse to the fracture, the fracture extends substantially vertically and linearly throughout the ice thickness. The typical shape of the ice upon interaction with offshore structures, when the ice is crushed under high pressure under pressure load, produces granular cracks. However, since the individual ice grains in the model ice are made of natural ice, i.e., have the strength of natural ice, the force required to generate granular cracks in the model ice is very large.

The ice crystal grains in the tight model ice formed by the spraying method (FIG. 5) are quite fine-grained and oriented without control. Such ice texture is called "granular". The mechanical properties of granular ice are nearly isotropic. The cracks formed under load follow the grain boundaries in this case as well. However, because the grains are substantially spherical and tightly packed together, the fracture has a non-planar surface such as occurs during bending loads. In a vertical cross section of ice stretched transverse to the fracture, the fracture occurs as a zigzag line oriented substantially perpendicularly. In order to crush the fine-grained model ice under a pressure load, it is not necessary to generate a granular crack due to the existence of many small crystal grains and many grain boundaries. Thus, in the case of model ice made by the spray method, the force required to crush the ice can be almost correctly graded.

Tense ice growth in the sea or in calm inland waters (Figure 6) mostly occurs like traditional model frozen columnar ice. Also in this case, usually, the crystal lattice structure of ice is formed corresponding to the columnar structure. In addition, a surface layer of granular ice, often about 5-30 cm thick, often occurs, especially in the case of sea ice. This surface development may be the result of freezing snow on the ice surface together or interfering with columnar ice growth to initiate the growth of tight ice.
The cause is, for example, wind, waves or tides. Grains that extend long into the lower area of the natural tense ice columnar structure typically extend from the ice surface (or the lower surface of the granular surface) to the lower surface of the ice due to various disturbances. The length of the crystal grains is rarely 20 to 30 cm or more. Many years of ice, especially in polar waters, often result in a layer of granular ice of some thickness forming an intermediate layer in the columnar water. The planar isotropy of the ice due to the columnar structure is weakened by all of these. However, due to the advantageous vertical orientation of the grain boundaries, the cracks in natural ice caused by bending loads extend almost straight through the ice thickness.

Under pressure load, natural ice is often crushed into somewhat fine grains. Natural ice usually exhibits a very brittle fracture state.

Stretched model ice made by known methods does not adequately satisfy the task of providing a physically correctly graded model of stuck ice as found in nature. Depending on the production method, the individual subranges are good, whereas the other ranges are poorly formed. For example, a model ice of taut columnar texture generated by freezing according to conventional methods forms a natural ice anisotropy and well forms a smooth fracture under bending load. Crushing of the ice under a pressure load is not preferred. This is because, in the case of such a fracture, granular cracks must be generated by columnar crystal grains. The individual grains have almost the strength of natural ice crystals, even after the temperature control process. That is, its strength cannot be graded according to the model. Further, the columnar grains of such model ice are too large. The fracture state of columnar tense crystal ice frozen in a conventional manner and temperature-controlled to obtain model-fit strength is ductile.

Furthermore, the density of model ice, which is important for the suspended state of a broken ice mass, is too large. The confinement of air bubbles (FIG. 7) in ice caused by blowing glass into the water portion using a porous hose has been shown to produce a density similar to nature in the case of columnar model ice connected in a conventional manner. to enable.

The gas trapped in the ice further reduces the cross-sectional area supporting it. Thereby, weakening of the model ice is achieved. Otherwise this weakening is achieved by part of the temperature regulation process. If you weaken the temperature control,
The ice breaks into a brittle state. The gas filling holes created by blowing gas into the water portion using a porous hose are about 1 mm in diameter and are too large to be able to act as effective stress concentrators.

Model ice tissue is not significantly affected by air bubble entrapment. The same applies when the synthetic resin particles are frozen in ice. The thickness of the fine-grained surface layer of columnar model ice, conventionally frozen on the ice surface by removing heat, depends on the choice of doping and the provision of the respective ice tank. The thickness of the granular surface is not actually affected.

The model ice generated and stretched by the spray process crushes the ice well under pressure load. This model ice has a fragility similar to nature. Some small air bubbles are trapped in the ice during the spraying process. Thereby, the suspended state of the broken mass from such model ice is more similar to the suspended state of the conventional columnar model ice which does not confine gas. However, the density cannot be controlled. The crystal grains in the model ice generated by the spraying process are small. However, the mechanical properties of such model ice are isotropic because the grains are oriented without adjustment. The typical anisotropy of natural taut ice is not shown. The fracture caused by the bending load has a zigzag uneven surface resembling nature.

Known methods for making taut model ice can produce a tissue that is sufficiently fine and at the same time exhibits natural ice anisotropy and texture. Adjustment of the density by controlling the gas insertion has hitherto only been possible in the case of a tight model ice with columnar structures, generated on the surface by freezing in a conventional manner, by removing heat. However, this ice has grains that are too large.

Problems, Solutions, and Effects Accordingly, an object of the present invention is to generate the following taut ice, especially for model experiments using ships and marine structures. That is, a strained ice that has a texture that at least substantially matches the texture of the natural strained ice, and whose deformation and destruction states are sufficiently sized to be sized, as observed with natural strained ice. Is to happen. This imitation also applies to the surface shapes and fracture shapes of the cracks that occur under various loads.

This object is achieved by the method according to claims 1, 2 and 3.

The first method according to the invention provides for the growth of columnar ice by placing a fine-grained ice growth base in the water portion so that fine-grained ice is obtained over the taut ice or in one or more layers. Interference is the formation of tight ice on the surface of the water. The taut ice preferably has any desired texture, similar to natural taut ice tissue.

Further, the present invention provides a second method for generating ice that is stuck on the surface of water to solve the problem. According to this method, the fine-grained ice growth groups are peeled off from the underside of the taut ice so that the fine-grained ice is obtained over the whole taut ice or in one or more layers. Tight ice is generated by interfering with columnar growth.

A third method is to mechanically remove the ice formed on the surface of the cold generator provided in the water portion so as to obtain fine-grained ice throughout the thickness of the ice or in one or more layers. The process produces fine-grained ice growth groups that are removed using the apparatus, thereby hindering the columnar growth of ice and producing tight ice.

According to the method according to the invention, ice with controlled texture is generated. Ice is obtained whose texture matches or resembles that of natural taut ice. In particular, in this way, the taut ice of different tissues can be properly modeled to be naturally similar. In this way, the length and diameter of the columnar ice crystals can also be limited when they are not desired. One extreme, "a columnar structure with long ice crystals reaching almost the entire thickness of the ice" (Figs. 2, 3)-which is caused by conventional unhindered growth-and the other extreme " Granular texture that reaches almost the entire thickness of the ice, with nearly spherical fine ice crystals oriented without sufficient control "(similar to FIG. 5)-this can continuously or shortly grow columnar growth. It is possible to generate any desired tissue between and-generated by interfering with time. The layers of granular ice and columnar ice are alternately formed to the same thickness or different thickness, and the size of the columnar grains in the organized columnar layer is
It can be limited by interposing a very thin layer or layers of ice growing groups. The ice generated and tensioned by this method satisfactorily mimics the texture of natural tensioned ice.

According to one method, the obstruction of the columnar growth base is such that fine ice growth bases, for example fine ice granules, are carried into the water area below the taut ice, with the area of the taut ice as a whole. Over the ice surface or over a partial area. The ice growing group is preferably
It is carried into the water part of the ice plate by the water containing it.
In this case, the growth groups are fed to the outside of the water part or are generated in the water part by a suitable device, for example a cooling device, together with the mechanical breaking of the ice generated there.

In another method, the obstruction of columnar growth is performed as follows. That is, the underside of the taut ice is treated by appropriate means so that the fine ice particles are detached or removed from the taut ice material, and the ice particles are deposited on the underside of the ice as new ice growth bases. It is done by doing. The treatment of the ice surface is preferably carried out by mechanical processing, for example by means of cutting using a suitable tool such as a brush or sharpener.

To mechanically scrape the ice crystals from the underside of the ice, it is advantageous if one or more shaving tools are used, in particular a shaving tool having a saw-tooth-shaped part at the edge which comes into contact with the ice.
Additionally or alternatively, one or more brushes can be used. The brush moves parallel to the ice surface and / or is rotationally driven. The pressing force pressing the working tool against the underside of the ice is adjusted or limited by suitable devices so as to avoid damage to the taut ice. The working tool is preferably mounted on the floating body. In the immersion state, the floating body provides a uniform and constant pressing force by means of a hydrostatic lifting device. The pressing force can be adjusted by ballast adjustment of the floating body. The working tool is further resiliently pivotable on the floating body. The floating body can be moved under the taut ice by a suitable device such as a rigging. The working tool can be moved and / or guided by an underwater vehicle moving under the taut ice. Further, the working tool can be attached to the underwater vehicle via the spring mechanism. Instead of or in connection with the spring mechanism, a force-adjustable pressing device can be used. The generation of the pressing force can furthermore be effected by means of a hydrodynamic lifting device.

In both cases, the density and porosity of the ice can be adjusted by introducing fine bubbles into the water below the ice in a manner known in principle. The fine bubbles rise, accumulate on the lower surface of the ice, and freeze in the ice as the ice grows. This can be achieved in a known manner by blowing air through a hose having fine holes. However, in the present invention, bubbles are preferably generated by pushing water supersaturated with gas under pressure into the water portion under the ice. The water under pressure releases gas upon expansion, forming very fine bubbles. The bubbles generated in this way are small enough to be able to act as effective stress concentrators when they are confined in ice, thereby making the resulting model ice brittle. However, a gas-producing chemical such as, for example, ammonium bicarbonate can be introduced into the water portion for gas insertion.

In the case of the method, further, as is known, solid particles, which do not act as ice-growing groups, are suspended or floatable in water, for example fine synthetic resin granules, are injected into the water part,
As a result, the particles form an intermediate layer in the ice as an obstruction point, which can have a good influence on the mechanical properties of the ice.

Advantageous embodiments of the invention are described in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS The method according to the invention will be described based on the exemplary embodiment shown in the figures.

FIG. 1 is a vertical sectional view of an ice layer made according to the present method. The ice layer has closed gas-filled holes and bent bends that extend almost flat.

2 to 7 are diagrams for explaining ice made according to a known method and natural ice to be imitated.

FIG. 2 is a vertical cross-sectional view of an ice layer having a columnar structure made by a conventional refrigeration apparatus.

FIG. 3 is a vertical cross-sectional view of a columnar ice layer having a fine-grained surface layer made from doped water in a conventional refrigerator.

FIG. 4 is a vertical cross-sectional view of an ice layer having a columnar structure with smooth bending fractures.

FIG. 5 is a vertical cross-sectional view of an ice layer of granular structure having uneven bending fractures produced by spraying.

FIG. 6 is a vertical cross-sectional view of a typical tense ice of nature, which has a fine-grained surface layer, a columnar grain of limited length, an intermediate layer of fine-grained water, It has bending cracks.

FIG. 7 is a vertical cross-sectional view of a columnar ice layer created by a conventional refrigeration system, the ice layer having trapped gas bubbles created by blowing gas directly into the water below the ice.

FIG. 8 shows that an ice growth base was added to the water portion under ice to produce taut ice obtained on the surface of the water portion in the container from the ice layer grown by the conventional method and the texture-controlled ice layer. FIG. 4 shows a dispensing device for placing.

FIG. 9 is a side view of an apparatus for generating an ice layer. In this case, the lower surface of the ice layer is mechanically worked by a shaving tool, and a pressing force is generated by a hydrostatic drive.

 FIG. 10 is a front view of the device according to FIG.

FIG. 11 is a diagram showing a device and a control block circuit diagram for generating an ice layer. In this case, the lower surface of the ice layer is mechanically processed by a rotating brush. The pressing force is kept constant by controlling the force.

FIG. 12 is a side view of an apparatus for generating an ice layer.
In this case, the ice growing groups are guided on the lower surface of the ice layer and occur there. In this case, fine bubbles are introduced into the water portion under the ice by gas supersaturated water under pressure to create a gas-filled hole in the ice.

FIG. 13 is a side view of an apparatus for generating an ice layer. In this case, the ice growing groups occur in the water portion below the ice.

DETAILED DESCRIPTION OF THE INVENTION AND BEST MODE FOR CARRYING OUT THE INVENTION FIGS. 2 to 7 are illustrations of the state of the art and ice imitated in nature. In this case, in FIG. 2, 110 indicates a very thin ice film, 130 indicates a directional crystal grain, and in FIG. 3, 210 indicates an ice film, 220 indicates a thin ice surface layer, 230 indicates a columnar crystal grain, and FIG. In FIG. 5, 330 indicates columnar crystal grains, 340 indicates cracks in tight ice, 410 indicates ice crystal grains, 440 indicates cracks extending in a zigzag shape, and 520 in FIG. 6 indicates a surface layer made of granular ice. , 530 indicates a columnar texture, 540 indicates a fracture, and 560 indicates a tank made of granular ice. W is the water portion in all figures.

In particular, in order to form tight ice for model experiments with ships or marine structures, the ice tanks 734, 834, 934, are first placed on the surface of the water portion indicated by W in FIGS. 1 and 8 to 13 by a known refrigerator. 1034,1134,1234,1334 are frozen formed. Ice growth is preferably initiated, as is known, by spraying a fine water mist 733,833,933,1033,1133,1233,1333 into cold air over ice-free frozen prepared water. . The fog droplets freeze in the air and sink on the ice-free water surface, where they naturally form a very thin, finely crystalline ice film. Below this ice film,
When doping with frozen water, a fine crystalline ice surface layer 1220 having almost no columnar structure is formed. The thickness of this ice surface layer depends on the type of doping and the freezing conditions of the ice container concerned, and is almost 0 to 5 mm. On the lower side 1221 of the fine crystalline surface layer 1220, or on the lower side 1211 of the ice film 1210 when this surface layer is not present, the growth of the columnar ice crystals 1232 is started when the cooling of the ice surface layer proceeds. You.

The growth of the columnar ice crystals 1232 is hindered by an ice growth base 1202 guided under the ice, for example, fine-grained ice particles. Here, providing the ice growing group includes generating the ice growing group from the material of the existing ice layer. From this ice growth base 1202, a thin layer of fine grain ice 1260 having a grain structure is formed. From this thin layer, columnar crystal grains 1230 start to grow anew. This columnar crystal grain 1230
The length of the ice growth base 1202 is below the ice forming the growth front.
Is newly limited. Ice growth base 1202
Continually or periodically for a short period of time, a layer of fine-grained ice 1262 is obtained at any desired thickness. If the cooling of the ice surface is continued, the growth of the columnar ice crystals 1231 starts again as soon as the guidance of the ice growth base 1202 is interrupted. Following the guidance of the ice growth base 1202 to the lower side of the ice by an arbitrary length,
The length of interruption can be any length, so that an ice layer of the desired tissue, the so-called tissue controlled ice 735,835,935,1035,1135,1235,1335, is obtained over the entire thickness of the ice.
Fractures 1240, such as those caused by bending in the ice layer obtained in this way, extend almost flat over the entire ice thickness. In the thick range of granular ice 1261, this crack 1240a
Need not be flat.

As is known, the thickness of the textured ice 1235, including unhindered grown ice on the surface of the ice layer 1234, is increased by the formation of bubbles 741,841,941,1041,1141,1241 during ice growth in the water area below the ice. , 1
Adjustable by inserting 341. Bubbles are trapped in the ice as gas filled holes 1270 at any horizontal location in the ice layer. When the gas containing hole 1270 is significantly smaller than about 1 mm in diameter, it acts as an effective stress concentrator, as well as a reduced support cross section. This stress concentrating member is advantageous because the ice that has passed through the gas holes is confirmed to be more brittle.

In the case of the method shown in FIG. 8, the taut ice composed of the ice layer 734 grown by the conventional method and the ice layer 735 whose texture is controlled is placed on the surface of the water portion W in the container 701 as follows. Is obtained. That is, the ice growth base 702 is obtained by putting the ice growth base 702 into the water portion W under the ice by a suitable distributing device 703 in the course of the growth of the ice 735 with controlled organization. Dispensing device
Because the 703 can move under the ice, a uniform or nearly uniform distribution of the ice growth base 702 occurs over the entire area of the taut ice or over a portion thereof. The ice growing medium is suspended in water according to the type of the stream containing the particles, and is conveyed from the storage container 706 to the distribution device 703 by the pump 704. The storage vessel 706 can be integrated with a device for generating ice growth groups. The water that carries the ice growing groups to the distribution device 703 is taken out of the water portion W into the container 701 by the pump 705 and sent out to the storage container 706. With this method, the initial generation of the conventional ice layer 734 due to the frozen fog 733 can be omitted, and instead the ice growing groups are introduced as follows. That is, the ice growth base 702 is put in the water portion W released from the surface of the ice, rises toward the surface, and according to the type of the ice layer indicated by 1260 and 1261 in FIG. Are introduced to form In this case, the formed and taut ice consists of ice 735 texture controlled throughout its thickness.

In the case of the method shown in FIGS. 9 and 10, taut ice composed of the ice layers 834 and 934 grown by the conventional method and the ice layers 835 and 935 whose texture is controlled is applied to the surface of the water portion W as follows. can get. That is, in the course of the growth of the ice 835, 935 with the controlled structure, the ice growth
It is obtained by scraping fine ice crystals from the underside of the taut ice which is deposited on the underside of the ice. In order to be able to smooth out the unevenness of the ice lower surface during the processing process and to generate the ice growth base 802 sufficiently uniformly over the processed surface, the shaving tool 81
It is advantageous to divide 1,911 into short sections and connect them so that they follow. At this time, it is advantageous to attach the section of the shaving tools 811, 911 to the rotatable lever mechanisms 812, 912. In this case, the flexibility is spring 813,913
Caused by In addition, shaving tools that come into contact with ice
Advantageously, the edges 811a, 911a of 811, 911 are formed in a sawtooth like a toothed spatula or the like. In addition, it is advantageous if the pressing force required to machine the lower surface of the ice is applied by lifting bodies 814,914. Thereby, a sufficiently constant and evenly distributed pressing force is obtained. By adding ballast to the lifting bodies 814,914 by weights or other appropriate means,
The pressing force can be reduced to zero and adapted to the requirements.
The shaving tools 811 and 911 can be separated from the taut ice by the force P acting on the lifting body. It is expedient for the lifting body to be pivotally connected to the underwater vehicle 817, 917 by means of bearings, such as pantograph mechanisms 816, 916, which do not hinder the dive movement, in order to receive the tilting moments generated by the shaving process and acting on the lifting body. This underwater vehicle is, for example, a rail 818 provided on the side,
Drive on the 918. A force F can be applied to the underwater vehicle 817. This force is necessary to move the device to one or the other under taut ice. This force can be generated, for example, by a rigging mechanism or the like, or by a specific drive of the underwater vehicle.

In the case of the method shown in FIG. 11, taut ice composed of an ice layer 1034 grown by a conventional method and a layer of ice 1035 whose texture is controlled is obtained on the surface of the water portion W as follows. In other words, it can be obtained by removing fine ice crystals from the lower surface of the stretched ice using a brush-like tool in the process of growing the ice 1035 whose texture is controlled. These fine ice crystals are
It is deposited on the lower surface of ice as 1002. It is advantageous to use a rotationally driven brush 1003 as a tool therefor. This brush is provided in the pressing mechanism 1010. This pressing mechanism supplies a pressing force necessary for peeling ice crystals. As an alternative to the generation of the pressing force by the hydrostatic lifting mechanism shown in FIGS. 9 and 10, a lever mechanism is illustrated in FIG. In the case of this lever mechanism, the pressing force is kept constant by adjusting the force. A rotating brush 1003, which may be a plurality of brushes, is supported at one end of a lever 1005 rotatably supported by a bearing 1006. An adjustable force generator 1007 acts on the free end 1005a of the lever 1005 via a spring 1008. This force generator provides the reaction force for the desired pressing force. The pressing force for pressing the brush 1003 against the lower surface of the ice is measured by the force measuring member 1004. This force measuring member is shown here integrated with the lever 1005. The bearing 1006 and the force generator 1007 are supported by the underwater vehicle 1017. This underwater vehicle is, for example, a rail provided on the side
Travel on the 1018. The underwater vehicle 1017 can be subjected to the force F required to move the device to one or the other under tight ice. This force can be generated, for example, by a rigging mechanism or the like, or by a specific drive of the underwater vehicle. The pressing force at that time measured by the force measuring member 1004 is supplied to the control device 1022 as an actual force value. The control device compares this value with the target value supplied from the target value detection member 1021, and provides a control signal to the output member 1023 according to the difference. The output member 1023 is, for example, a servo hydraulic device or the like. The output member activates the force generator 1007. That is, in the case of the servo hydraulic device, the hydraulic piston is slid. In a simple embodiment, the force control circuit including the force measuring member 1004, the target value detecting member 1021, the control device 1022, the output member 1023, and the force generator 1007 is omitted, and the pressing force is controlled by the shape device of the device, the spring 1008. It is determined only by the spring characteristics and its instantaneous deflection.

In the case of the method shown in FIG. 13, taut ice consisting of an ice layer 1334 grown by a conventional method and ice 1335 whose texture is controlled is obtained on the surface of the water portion W as follows. That is, it is obtained by generating an ice growth group 1303 in the water portion W under the ice in the process of growing the ice 1335 whose texture is controlled. For this purpose, a low-temperature generator 1303, for example, a heat exchanger filled with a refrigerant, is placed in the water portion W. Ice 1304 is formed on the surface of the low temperature generator 1303. Fine ice crystals are peeled from the ice by mechanical treatment using a suitable device 1305, for example, shaving or brush shaving with a rotating brush or the like, or vibration. The ice crystal serves as an ice growing base 1302. Low temperature generator 1303
And an apparatus 13 for removing ice crystals from the formed ice 1303
Advantageously, 05 and 05 are mounted on a common underwater vehicle 1317.
The underwater vehicle runs on rails 1318 and can reciprocate under the tight ice. In this case, too, the first generation of the conventional ice layer 1334 by the connected fog 1333 can be omitted, and instead, the ice growing base 1302 in the water portion W where the ice has been released at the surface. By putting
Ice growth begins. The ice growing groups rise toward the surface, where they form a fine-grained ice layer, such as the ice layers shown at 1260 and 1261 in FIG. In this case, the evolved and taut ice also consists of tissue-controlled ice 1335 throughout its thickness.

8 to 13, 741, 841, 941, 1041, 1141, 1241 or 1341 indicate bubbles rising in the water portion. The air bubbles, when frozen in the ice body, serve to adjust the thickness of the ice or to weaken the ice. For bubbles as small as possible, it is advantageous to generate these bubbles in the course of the outgassing of gas supersaturated water under pressure. In this case, it is advantageous to connect a device for introducing air bubbles into the water portion and a device for producing ice with controlled tissue. FIG. 12 exemplarily shows such a device. In some cases, in the water portion W below the taut ice consisting of the ice layer 1134 frozen in a conventional manner and the texture-controlled ice 1135, an apparatus 1103 for generating ice growing groups according to one of the methods is provided. In some cases, it is provided on an underwater vehicle 1117 running on a rail 1118. The same underwater vehicle 1117 contains gas supersaturated water 1142
A discharge device, such as a porous tube, is attached. Gas supersaturated water is generated from device 1143. In this device, water removed by a pump 1145 from a water portion W is supersaturated with gas under pressure. The compressed gas is extracted from a compressed gas generator 1144, for example, an air compressor, a compressed gas container, or the like, and pushed into a supersaturation device 1143. The device for generating gas supersaturated water may be wholly or partially located on the underwater vehicle 1117.

The invention is not limited to the embodiments described above and those described in the claims. Other embodiments of the combination of the above method means or device, as well as the use of equivalent means or measures in each case, are within the scope of the present invention. This equalizing means or strategy may use, for example, a hydrodynamic lifting device to generate a pressing force, for example, by removing ice crystals from the underside of the ice by moving water or by stress cracks generated by vibration or by heat. A method different from the cutting method for peeling, or a method different from the cutting method for generating air bubbles in water, for example, using a chemical product that generates gas, or discharging gas dissolved in water in a foamy form Is to use a vibrating vibration.

The above-described method and apparatus provide controlled-texture ice having a predetermined crystal structure for model experiments. This ice conforms to the structure of natural ice. This also applies to the shape and fracture shape of the fracture surface.

──────────────────────────────────────────────────続 き Continuing the front page (72) Inventor Lup Karl-Heinz, Germany, Day 2000-Hambrk 71, Stockrosenweg, 79 (72) Inventor Ephers Carl-Ulrich, Germany, Day -2000 Hambruck 65, Zomemapfado, 2 (72) Inventor Heusler Franz Ulrich, Germany-2071 Sieg, Grossbrecken, 8 (56) References JP 62-169977 (JP, A) JP-A-62-145132 (JP, A) JP-A-61-243265 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 10/00 F25C 1/00

Claims (41)

(57) [Claims] 1. A method for generating taut ice on a water surface of a water part, particularly for model experiments with ships or offshore structures, the method comprising the steps of providing fine-grained ice over the entire thickness of the ice or in one or more layers. So that you can get ice,
A method of producing tight ice by interfering with ice columnar growth by placing fine-grained ice growth bases in a water portion. 2. A method for generating taut ice on a surface of a water part, particularly for model experiments with ships or offshore structures, comprising the steps of providing fine-grained ice over the taut ice or in one or more layers. So that you can get ice,
A method of producing a tight ice by peeling off a fine-grained ice growth base from the lower surface of the tight ice, thereby hindering the columnar growth of ice. 3. A method for generating taut ice on a water surface of a water portion, particularly for model experiments with ships or offshore structures, the method comprising the steps of providing fine-grained ice over the taut ice or in one or more layers. So that you can get ice,
Tight ice is generated by interfering with the columnar growth of ice by generating fine-grained ice growth bases, and ice growth bases dissolve ice formed on the surface of the low-temperature generator provided in the water part. A method characterized in that it is peeled off by mechanical processing in an apparatus. 4. An ice growing group in the form of fine-grained ice granules,
2. The method of claim 1, wherein the method is placed in a water portion under ice. 5. The method as claimed in claim 1, wherein the ice-growing substrate is introduced into the water portion by flowing water. 6. A method as claimed in claim 1, wherein the ice-growing groups contained in the water portion are generated in a water portion below the ice. 7. The method of claim 1, wherein the ice growing group placed in the water portion is obtained from ice frozen in the water portion below the ice by one or more cold generators. The method of any one of paragraphs 1 to 6. 8. The method according to claim 2, wherein the processing of the lower surface of the ice is performed in a mechanical working form. 9. The method according to claim 2, wherein the processing of the lower surface of the ice is performed by a cutting means or a tool such as a shaving tool or a brush. 10. The method according to claim 2, wherein the treatment of the lower surface of the ice is performed by moving water, for example, one or more water jets. Method. 11. A method according to claim 2, wherein the processing of the lower surface of the ice is performed by vibration. 12. The pressing force required for processing the lower surface of ice is as follows:
Claims 2 and 8 characterized in that they are generated by a hydrostatic lifting device, such as a lifting body.
The method of any one of ~ 11. 13. The method according to claim 2, wherein the pressing force obtained by the hydrostatic lifting device can be adjusted, for example, by ballast adjustment with a ballast weight or a filled liquid. 12. Any one of the methods of paragraph 12. 14. The method according to claim 2, wherein a pressing force required for processing the lower surface of the ice is obtained by a lever mechanism. 15. The method according to claim 2, wherein the pressing force required for treating the lower surface of the ice is obtained by a spring mechanism. 16. The method as claimed in claim 2, wherein the required pressing force for the treatment of the lower surface of the ice is obtained by means of a hydrodynamic lifting device. 17. The pressing force required for processing the lower surface of ice is as follows:
17. A method according to any one of claims 2 and 8 to 16, characterized in that it is obtained by one or more force generators, such as a liquid cylinder, a pneumatic cylinder, a reciprocating spindle. 18. The pressing force required for treating the lower surface of the ice, obtained by one or more force generators, can be adjusted sufficiently freely by a force adjusting circuit. Clause 2 and any one of clauses 8-17. 19. The method according to claim 1, wherein bubbles are taken into the water portion. 20. The method according to claim 19, wherein the incorporation of bubbles into the water portion is effected by supersaturated water under pressure. 21. The method according to claim 19, wherein the incorporation of gas bubbles into the water portion is performed by incorporating a gas generating chemical into the water portion. 22. The method according to claim 19, wherein the bubbles dissolved in the water are discharged in the form of bubbles by pressure fluctuations such as shock waves and sounds generated in the water. Item 19. 23. The method according to claim 1, wherein floating solid particles or solid particles substantially floating in water are incorporated in the water portion. 24. An ice layer (734) grown in a conventional manner;
Apparatus for a method of generating taut ice consisting of a texture-controlled ice layer (735) on the surface of a water portion (W) in a container (701), wherein the apparatus places an ice growing medium (702) under the ice. And a storage container (706) having a pump (704) for supplying the ice growth base (702) to the distribution device (703) (FIG. 2). 8) This ice is formed on the surface of the water portion (W) in the container (701) by the ice layer (734) grown by the conventional method and the water layer (73) whose tissue is controlled.
5) A device characterized by comprising: 25. Apparatus according to claim 24, wherein an apparatus for generating ice growth groups is provided in the storage container (706). 26. An apparatus comprising a shaving tool (811, 911) provided in a container containing a water portion for peeling fine ice crystals from the lower surface of the taut ice. Apparatus for the method of generating the taut ice of item 2 (FIGS. 9 and 10). 27. The shaving tool (811,911) is divided into short sections, and this section is pivotally attached to at least one underwater vehicle (817,917) movable below the taut ice. 27. The device of claim 26. 28. A section of a shaving tool (811, 911) provided on a rotatably mounted lever mechanism (812, 912) and a spring (813, 913) provided for flexibility. The device of range 27. 29. A shaving tool (811,91) on ice.
Device according to any one of claims 26 to 28, characterized in that the edges (811a, 911a) of 1) are formed like toothed spatula or in a sawtooth shape. 30. In order to obtain a pressing force of the shaving tool (811, 911) against the tight ice lower surface, a lifting body (8) is provided.
The apparatus according to any one of claims 27 to 29, wherein the underwater vehicle (817,917) is provided on a movable underwater vehicle (817,917). 31. A lifting body (814,914) having a weight (915).
31. The device of claim 30, wherein the ballast has been added. 32. In order to receive a tilting moment acting on the lifting body (814, 914) during the shaving process, the lifting body (814, 914) does not impede diving movement, for example by means of a support such as a pantograph mechanism (816, 916). Apparatus according to any one of claims 30 and 31, characterized in that it is pivotally attached to a possible underwater vehicle (817,917). 33. Apparatus according to claim 30, wherein the underwater vehicle (817,917) runs on a rail (818,918) laid on the bottom side. 34. Apparatus for the method of generating taut ice according to claim 2, wherein a brush-like tool is provided for peeling fine ice crystals from the underside of the taut ice. An apparatus characterized in that it is formed as a rotatably driven brush (1003) and is provided on a pressing mechanism (1010), the pressing mechanism supplying a pressing force necessary for peeling ice crystals (FIG. 11). 35. One or more rotating brushes (100
3) is provided at one end of a double-armed lever (1005), this double-armed lever is rotatably supported by a bearing (1006), and a spring (1008) is attached to the free end (1005a) of the lever (1005). Acting, this spring is operatively connected to the adjustable force generator (1007), the pressing force pressing the brush (1003) against the ice surface,
It can be measured by a force measuring member (1004), which is integrated with the lever (1005) and the bearing (1006) and the force generator (1007) are at least one movable below the taut ice. 35. Apparatus according to claim 34, supported by two underwater vehicles (1017), said underwater vehicles being able to run on rails (1018) provided on the bottom side. 36. A force measuring member (1004) for measuring a current pressing force as an actual force value cooperates with a control device (1022), and the control device comprises a target value detecting device (1021) and an output member. 36. The device according to claim 35, wherein the device is connected to (1023) and the output member (1023) is formed, for example, as a servo hydraulic device. 37. An apparatus for a method of producing taut ice according to claim 3, wherein the tissue controlled ice (13) is provided.
In order to generate an ice growth base (1302) under the ice during the growth of 35), a low-temperature generator (1303) is provided in the water part (W) and forms on the surface of the low-temperature generator (1303) An apparatus (1305) for mechanically processing the collected ice. 38. Apparatus according to claim 43, wherein the apparatus (1305) comprises at least one rotating brush. 39. The apparatus according to claim 37, wherein the apparatus includes a vibrating device for separating fine ice crystals from ice (1304) formed on the surface of the low-temperature generator (1303).
Equipment of the term. 40. A low-temperature generating base (1303) and a device (1305) for removing ice crystals from the formed ice (1303) are provided on a movable underwater vehicle (1317), and the underwater vehicle is provided with a water-based vehicle. Rail (131) provided on the bottom side of the container in the part (W)
8) Claim 3 characterized by being able to run on
The apparatus according to any one of paragraphs 7 to 39. 41. A device for entraining air bubbles into the water portion is connected to a device for making tissue-controlled ice, and the device for generating ice growing groups (1103) is provided with a device for producing water under the taut ice. In a section (W) mounted on a mobile underwater vehicle (1117), the underwater vehicle (1117) comprises a discharge device (1142) for gas supersaturated water, such as a porous tube, and comprises gas supersaturated water. Equipment (1143) is provided, which is connected to a pump (1145) for removing water from the water portion (W) and provides a compressed gas generator (1144), an air compressor or a compressed gas. Apparatus according to any one of claims 24 to 40, characterized in that a pressure vessel for taking out and a supersaturation device (1143) are provided.