Simplified calculation simulation device and simulation method for ship ice collision in aqueous medium
Technical Field
The invention relates to a simplified calculation simulation device and a simplified calculation simulation method for ship ice collision in an aqueous medium, and belongs to the field of ships.
Background
With the rapid development of economic construction in China, marine economy becomes a new growth point of national economy, the development of arctic and the opening of arctic channel not only provide new guarantee for new strategy in China, but also shorten shipping time, but with the large-scale development of marine development, the problems of sea ice disaster influencing the safety and operation of marine structures and interaction between sea ice and the structures are increasingly prominent. The ship running in the polar region inevitably collides with the ice body, the ship ice collision is a complex nonlinear process, and the research on the ship ice collision in the water medium increases a layer of difficulty. Current research generally considers the effect of water by applying an aqueous medium as an additional mass to the hull, and neglects the effect of the change in water pressure of the aqueous medium during a boat-ice collision. The instant strong impact force generated during ship ice contact collision is indeed the load most worth paying attention to the research on ship-ice collision, and in fact, in the ship-ice near-field approaching process before ship ice contact, the water between ship ices generates a high pressure field in advance due to the squeezing between ship ices, the high pressure field generates an instant high pressure load on a ship body structure, and the pressure field is out of danger to the ship body when the speed of the ship-ice contact is taken as a calculation origin. Some scholars also consider the action of water through fluid-solid coupling, and although the software and hardware of modern computers are continuously upgraded, the fluid-solid coupling method needs a large amount of calculation time due to the adoption of a finite volume method to process the fluid units, and the calculation time is about several times of that of a non-fluid-solid method.
Disclosure of Invention
The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention provides a pressure testing device for replacing water influence in the ship ice collision process, which monitors the water pressure load of a ship body collision area in the whole process before the ship collides with ice in real time, verifies numerical simulation, realizes that the influence of a water medium generated by full coupling of the ship, water and ice on the ship ice collision load is converted into the preload on a ship body collision surface, achieves the decoupling purpose, can develop high pressure loads of different ice body shapes, ice body qualities, collision speeds, collision positions, ship model floating states and collision angles on the premise of not using ice materials, better reflects the real condition of ship and ice collision, and has low cost, easy operation and small risk.
The technical scheme is as follows: in order to solve the technical problem, the simplified calculation simulation device for ship ice collision in aqueous medium comprises a water tank, wherein a liftable support frame is arranged in the water tank, an ice body model is placed on the support frame, a ship model is placed in the water tank, a guide rail is arranged on the water tank, a towing device is arranged on the guide rail and is connected with the ship model through a towing truss, a pressure sensor is arranged at the top end of a ship and is sequentially connected with a charge amplifier, a multi-channel signal acquisition instrument and a computer; the ship is driven to collide with the ice body model through the movement of the towing device, so that collision data are collected through the pressure sensor.
Preferably, the ship model is provided with a protection device, the protection device is an L-shaped piece, one end of the protection device is fixed on the towing truss, and the other end of the protection device is positioned on the front side of the bow.
Preferably, a fishing device is further arranged in the water tank, the fishing device comprises foam and a string, and the foam is connected with the ice cube model through the string.
Preferably, the pressure sensor is installed in a reserved small hole around the impact of the outer plate of the ship model and is fixedly sealed by glass cement.
Preferably, the non-impact surfaces of the ice mold are provided with openings.
Preferably, the support frame comprises fixed frame, supporting platform and lifter, and fixed frame width is greater than the ship model width, highly is less than the trailer, and the frame both sides are furnished with the nut, and the lifter is the bar iron with the screw thread.
A simulation method of the ship ice collision simplified calculation simulation device in the water medium comprises the following steps:
1) placing a support frame in the middle of a water pool, then placing an ice body model on the support frame, adjusting the distance between the bearing surface of the support frame and the bottom wall of the water pool to ensure that 80% of ice bodies are submerged below the water surface, and finally adjusting the ice body model on the bearing surface of the support frame to determine an impact angle and an impact position;
2) putting the ship model into a preassembly position, adjusting the draft of the ship model, and towing the truss to fix the ship model and the trailer;
3) and starting the trailer, enabling the ship model to impact the ice body at a set collision speed, stopping braking the trailer and collecting data.
Has the advantages that: compared with the prior art, the invention has the following advantages:
1) the influence of a water medium generated by the full coupling of the ship, water and ice on the ship ice collision load is converted into the preload on the ship collision surface, the decoupling purpose is achieved, and accurate load input is provided for the ship-ice collision numerical simulation in the whole process.
2) On the premise of not using ice materials, model tests of different ice body shapes, ice body qualities, impact speeds, impact positions, ship model floating states and impact angles can be carried out, the real situation of ship and ice impact is well reflected, the cost is low, the operation is easy, and the risk is small.
3) According to the invention, the ship body does not need to be contacted with the ice body model, the protection device prevents the ship model from impacting the ice body model, and the next working condition experiment can be carried out only by adjusting the posture of the ice body model after fishing.
4) The ice body model is quickly sunk into the water by opening the non-impact surface of the ice body.
5) The height of the supporting frame can be adjusted according to the ice body model, and the requirements of experiments are met.
Drawings
FIG. 1 is a side view of the ship ice water pool experimental facility of the present invention;
FIG. 2 is a cross-sectional view of the experimental apparatus A-A of the ice water tank of the ship of the present invention;
FIG. 3 is a schematic view of an information acquisition device;
in the figure: the system comprises a ship model 1, a towing device 2, a protecting device 3, an ice body model 4, a supporting frame 5, fishing devices 6 and 7, a data acquisition system 2-1, a towing truss 2-2, a fixed frame 5-1, a supporting platform 5-2, a lifting rod 5-3, a nylon rope 6-1, foam 6-2, a pressure sensor 7-1, a charge amplifier 7-2, a multichannel signal acquisition instrument 7-3 and a computer 7-4.
Detailed Description
As shown in the attached drawings 1 to 3, the experimental devices adopted by the simplified calculation simulation device for the ice-on-water collision of the ship in the water medium are a ship model 1, a towing device 2, a protection device 3, an ice body model 4, a support frame 5, a fishing device 6 and a data acquisition system 7.
In the invention, the collision part of ship ice in an aqueous medium is mainly the ship bow and the shoulder part of a ship body, a ship model adopts a ship bow model processed by glass Fiber Reinforced Plastic (FRP) and a Freund plate according to a real ship reduced scale, a towing device comprises a trailer 2-1 and a towing truss 2-2, the towing truss fixes the ship model and the trailer, the protection device is an L-shaped plate, one end of the protection device is fixed on the towing truss, the other end of the protection device is positioned on the front side of the ship bow, the ice model is a hollow iron box processed by a steel plate, the support frame is a telescopic support frame, the fishing device is a nylon rope 6-1 and foam 6-2, one end of the nylon rope is tied on the ice model, and the other end is tied on the foam. The data acquisition device comprises a pressure sensor 7-1, a charge amplifier 7-2, a multi-channel signal acquisition instrument 7-3 and a computer 7-4, wherein the pressure sensor is fixed at a ship model surface measuring point position through glass cement, and the charge amplifier, the multi-channel signal acquisition instrument and the computer for collecting pressure sensor signals are arranged on the trailer. The support frame comprises fixed frame, supporting platform and lifter, and the fixed frame width is greater than the ship model width, highly is less than the trailer, and the frame both sides are furnished with the nut, and the lifter is for taking the screwed rod iron, is equipped with lifting nut on the supporting platform, and supporting platform's both sides are equipped with the boss, are equipped with the direction recess on fixed frame, thereby lifter and lifting nut cooperation, thereby through the reciprocating of the rotation drive supporting platform of lifter.
The simulation method of the ship ice collision simplified calculation simulation device in the water medium comprises the following specific steps:
1) placing the telescopic support frame in the middle of the water pool, then placing the ice body model on the telescopic support frame,
the distance between the bearing surface of the expansion bracket and the bottom wall of the water tank is adjusted, so that 80% of ice bodies are submerged below the water surface. Finally, adjusting the ice body model on the bearing surface of the support frame to determine the impact angle and the impact position;
2) putting the ship model into a preassembly position, adjusting the draft of the ship model, and towing the truss to fix the ship model and the trailer;
3) starting the trailer, the ship model will be with collision velocity striking ice body, and at this moment, the ice body model is touched by protection device earlier and is sunken under water, and the trailer brake stops, data acquisition.
4) And fishing the ice body model, replacing the shape and the size of the ice body, adjusting the impact speed, the impact position, the floating state of the ship model and the impact angle, and performing impact experiments according to the experimental steps again.