Device for towing test of model drilling platform in the model tank
(57) Abstract:The invention relates to experimental fluid mechanics of engineering structures and relates to devices for testing models of drilling platforms in the model tank. The device has a tow truck with a fixed frame with a barbell. The transverse stiffness of the rod height is variable. Dynamometer with sensors forces and moments connects the rod with a towed model. On the frame secured additionally two bars with dynamometers and rods. The simulator of the seabed in the form of flat plates, suspended to a frame through dynamometers. The gap between the plate and the model may vary with tie rods installed symmetrically relative to the longitudinal axis of the device at a distance from each other. One of the rods are rigidly connected to the dynamometer, containing sensors longitudinal and vertical forces, and the second link is connected pivotally with a dynamometer, containing the sensor vertical force. The opposite ends of rods pivotally connected to the simulator bottom. Traction has the device adjust their length. Surface simulator from model covered with removable rough plate with specified roughness parameters. Fourth dynamometer of the Soyots trim, roll and drift. The technical result of the invention consists in the approximation of the conditions of the model tests in ice model tank to the conditions close to real, and allow modeling of the impact on the seabed processes literatrure ice formations around the model and the measurement of forces and moments arising from the breaking of the ice on the model as a whole, and on its bottom and the seabed. 1 Il. The invention relates to experimental hydrodynamics of ship and marine engineering structures and for equipment for testing models of drilling platforms in the ice model tank.A device for towing test of model drilling platform in the model tank, made according to the patent of the Russian Federation 2072681, class B 63 B 9/02 containing towing a cart with a fixed frame with a barbell, made with variable height transverse stiffness and related towed model through the dynamometer with sensors forces and moments prototype.A disadvantage of the known devices is the inability to simulate the effects of the seabed on the physical processes of breaking ice formations around the drilling platform and the resulting forces and IOM is near the ice-resistant platform.The claimed invention solves the problem of providing test model drilling platform in the ice model tank in conditions close to real ones, allowing to model the influence of the seabed on the physical processes of breaking ice formations around the model of the drilling platform and to measure the resulting forces and moments on the model as a whole, on its bottom and the seabed.For this purpose, the device is further provided with two rods fixed to the frame of the towing truck, with dynamometers and rods, the simulator of the seabed in the form of flat plates, suspended through dynamometers to the frame of the towing truck with the possibility of changing the gap between the plate and the model with tie rods installed symmetrically relative to the longitudinal axis of the device at some distance from each other, with one of the rods are rigidly connected to the dynamometer, containing sensors longitudinal and vertical forces, and the second link is connected pivotally with a dynamometer, containing the sensor vertical force, the opposite ends of the rods connected to the simulator, bottom hinge, moreover, the thrust provided with a device for adjustment of their length, and the surface simulator bottom side of the model covered by the social plane, when this part of the model are connected through the fourth dynamometer containing sensors longitudinal, lateral and vertical forces, as well as sensors moments of pitch, roll and drift.Equipment device simulator of the seabed, which is rigidly fixed on the frame of the towing truck through additional dynamometers and hauled into the channel of the ice model basin together with the model of the drilling platform, allows you to create test conditions model drilling platform, the transformation and accumulation of ice in front of the platform, close to real. For this purpose, the plate simulator seabed exceeds the dimensions of the tested model of the drilling platform and forward of the front of the model about its length so as to cover the entire volume of the destroyed rig as it moves hummocky ice formation. Held by the simulator of the seabed with piles of pieces of the destroyed Toros in front and at the sides of the drilling platform materially affect the forces and moments measured by the dynamometer, to which is suspended a model of the drilling platform. The reliability of the obtained information about the forces and moments acting on the drilling platform, significantly increased(usually 5 - 10 mm) and adjustable so that, on the one hand, to avoid mashing the model on the bottom plate, and on the other hand, to prevent the entry of debris of broken ice between the bottom of the model and plate simulator bottom. These requirements are provided in the device adjustable gap.Thrust placed symmetrically relative to the longitudinal axis of the device in order to exclude creasie moments of the weight of the simulator bottom and their impact on the work of dynamometers, as well as to thrust were trace ("shadow") for a model of the platform and do not interact with ice.For designing a drilling platform is not enough to know the forces and moments acting on the platform in General. You must know what portion of these forces and moments from the impending ice field ice acts on the individual elements of the construction of drilling platforms, in particular in the area of the waterline (usually this part of the design made in the form of a truncated cone) and more submerged structural elements (the so-called ice-resistant base), as well as forces and moments acting on the seabed near the ice-resistant platform.The claimed device provides measurement listed is further introduced into the device dynamometers. And the model of the drilling platform is designed split in a horizontal plane below a truncated cone, with parts of the model are connected through the fourth dynamometer.The interaction of the drilling platform with the Taurus, a pile of shattered ice near the drilling platform and the resulting forces and moments depend on the roughness of the seabed. To study this effect and recalculate the results of the model ypitanii on the nature of the simulator is equipped with a removable bottom plate with specified roughness parameters.To exclude the effects of bending moments on the accuracy of the measurement of forces on the simulator seabed it is connected to the articulated rods. The upper end of the rear traction is connected to the dynamometer through a hinge to provide this traction necessary degrees of freedom in the longitudinal direction. In this case, the longitudinal force acting on the simulator bottom, is one dynamometer installed in the front foot.The essence of the claimed invention is illustrated in the drawing, which shows a diagram of the device, side view.The device comprises rigidly mounted on the towing carriage frame 1 with weights 2, 3, through which the load cells 4, 5, 6 suspended model binoy axis of the device and connected to the simulator of the seabed through the hinges 10, rear traction is equipped with hinges 10 on both ends, and provided with a device for adjustment of their length 11 made in the form of a spiral pair of screw-nut. Simulator seabed 9 is covered with a removable rough plate 12 with a predetermined roughness parameters. Model drilling platform 7 are split in a horizontal plane. The lower part of the model 13 is connected with the upper part 7 through a 6-component dynamometer 14 containing sensors longitudinal, lateral and vertical forces, as well as sensors moments of pitch, roll and drift. The model is towed in the ice box 15 Toros 16.Dynamometer 4, to which is suspended a model of the drilling platform, is also 6 component and measures the longitudinal, lateral and vertical forces and moments trim, drift and roll acting on the model as a whole, i.e., on its upper and lower parts. By subtracting the readings of the respective sensors, load cells 4 and 14 receive the values of the forces and moments acting on the upper part of the model.Dynamometer 5 contains sensors longitudinal and vertical forces. Dynamometer 6 contains only the sensor vertical force. The addition of sensors vertical forces of the two dynamometers 5 and 6 determine the total supply power P at the bottom is determined by the formula:
L = PZ6/PZb-a
where L is the distance from the point of application of force P to the Z-axis of the model;
b - the distance between the rods 8;
a - the distance between the Z axis of the model and the front thrust 8.The longitudinal force acting on the simulator seabed, is determined according to the indications of the respective sensor dynamometer 5.The gap between the model of the drilling platform and the simulator of the seabed 9 is regulated by the screw 11 pairs.The device operates as follows. Collect part of the model 7 and 13 on the dynamometer 14. Fix the model on the dynamometer 4. Collect simulator bottom 9 by hinges 10 and the tie rods 8, bring it under the model of the drilling platform and fixed on the load cells 5 and 6. Install the necessary clearance between the bottom of the model 13 and rough plate 12. Specify the movement of a towing truck.When driving a tow truck in the model tank on the parts of the model 7 and 13 of the drilling platform and the simulator of the seabed 9 arise hydrodynamic and ice loads from breaking the ice fields 15 and Toros 16. These forces and moments are transmitted to the load cells 4, 5, 6, 14. According to the testimony of these dynamometers are all required power settings on the parts of the model and the simulator of the bottom.
FIELD: experimental hydromechanics; designing of equipment for conducting hydrodynamic and ice searches of marine engineering facility models in model testing basins.
SUBSTANCE: proposed device includes towing trolley with frame rigidly secured on it; this frame is provided with bar which is connected with model through dynamometers and bearing plate. Dynamometers form three-support force-measuring system; they are provided in each support in form of two interconnected elastic members; one elastic member is made in form of five-rod member provided with longitudinal and lateral force sensors; it is located between two flanges. Second elastic member of dynamometer is made in form of membrane-type elastic member whose membrane is located between rigid rim and rigid central part of this member provided with threaded rod with elastic hinge mounted over vertical axis perpendicularly relative to membrane. Membrane, rim and rigid central part with threaded rod and elastic hinge are made integral. Rim of membrane elastic members is rigidly connected with one of flanges of five-rod elastic member in such way that threaded rod is located along vertical axis of support and is rigidly connected via elastic hinge with bearing plate secured on model. Membrane is provided with resistance strain gages forming vertical force measuring bridge. Second flange of each five-rod member is connected with additional bearing plate secured on bar.
EFFECT: enhanced accuracy of measuring forces and moments.