The simulation method of immersing the body in water
(57) Abstract:Usage: in experimental hydrodynamics. The essence of the invention: a water tank installed two vertical shield 2 and 3, made of a transparent material. The distance between the panels defined by the length of the sleeves 4, attached by screws 5, is chosen equal to the maximum transverse size 6 body, immersion in which water is modeled. Model 6 is placed between the panels 2 and 3 and originally released by recording the trajectory of the immersion model 6 under the influence of negative buoyancy. Model 6 moves between the panels 2 and 3 , which do not allow it to deviate to the side, simulating the stabilization of the body on the course. The transparency of the panels 2 and 3 allows you to record the trajectory using a photo or filming , as well as visually. At the intersection of the trajectory immersion model 6 and the bottom of the tank, fix, block 8, passed through him, a flexible connection 9 attach one end to the model 6. The force that simulates traction engines, create by flexible connection 9, which its free end is slid on the surface of the block 10 and is attached to the load 11. Then again lowered model 6 in a tank of water, placing it between the panels 2 and 3. On this curvilinear trajectory cargo 11 release. When this force in the flexible connection 9 are directed along the axes 6 and thrust propulsion thrusters. 2 Il. The invention relates to experimental hydrodynamics and comes to technology research and modeling of immersing the body in water.There is a method of modeling immersing the body in water, in which are immersed the model body in a tank of water and create a force on the model, additional to its negative buoyancy, while the force on the model is passed through a flexible connection passing through a point located at the intersection of the trajectory of the free immersion model with the bottom of the tank.There is a method allows to accurately simulate immersion in water, however, cannot be used to simulate this process, when the stage dive underwater vehicle make its stabilization course. This stabilization is necessary due to the fact that because of the inevitable geometric and force (weight) asymmetry of the body (especially when diving to great depths) it will move in a spiral and will come in the area with great uncertainty as to coordinate and azimuth. When carrying out the known method it is possible to pull the of the body in the water with the stabilization of the exchange rate reduces the functionality of this method.The aim of the invention is to enhance the functionality of the method by simulating the stabilization of the body on the course during the dive.This goal is achieved by restricting the deviation of the model by two transparent vertical panels, which are placed with a mutual distance from each other at a distance equal to the maximum transverse size of the body.In Fig. 1 shows a diagram of a device for implementing the method, side view; Fig. 2 - same as above.The proposed method is implemented as follows. In the tank 1 with water to make two vertical shield 2 and 3, made of a transparent material, such as organic glass. The distance between the panels defined by the length of the sleeves 4, attached by screws 5, is chosen equal to the maximum transverse size 6 body, immersion in which water is modeled. Model 6 is placed between the panels 2 and 3 and originally released by recording the trajectory of 7 dives model 6 under the influence of negative buoyancy. Model 6 moves between the panels 2 and 3, which do not allow it to deviate to the side, simulating the stabilization of the body on the course. Prozracnosti path 7 and the bottom of the tank 1 is fixed block 8, pass through it flexible connection 9 (e.g., wire) and attach one end to the model 6 body. Creating efforts, simulating thrust propulsion is via a flexible connection 9, which its free end is slid on the surface of the block 10 and is attached to the load 11.Then again lowered model 6 in tank 1 with water, placing it between the panels 2 and 3. The curvilinear section I of the trajectory 7 does not create flexible connection 9 tension (excluding the effect of the load 11, which hand, and the slack of the flexible connection is chosen), and the rectilinear section II trajectory 7 cargo 11 release. When the process is achieved by modeling the process of immersion, the corresponding in-situ process, as the curvilinear section I of the trajectory of the immersion model 6 occurs only under the influence of negative buoyancy, and the rectilinear section II, when the longitudinal axis of the model 6 and a flexible connection 9 are located along the path 7, that is, the tension in the flexible links are directed along the axis of the model, as thrust propulsion thrusters, model 6, there is an additional force, and the immersion process is accelerated.The effectiveness of the proposed method is determined by the fact that, compared with the method of the prototype at e is odnovremenno stabilization him on the course. The SIMULATION METHOD of IMMERSING the BODY IN WATER, in which are immersed the model body in a tank of water and create a force on the model, additional to its negative buoyancy, while the force on the model is passed through a flexible connection passing through a point located at the intersection of the trajectory of the free immersion model with the bottom of the tank, characterized in that limit the deviation of the model by two transparent vertical panels, which are placed with a mutual distance from each other at a distance equal to the maximum transverse dimension of the model body.
FIELD: mechanical engineering; testing facilities.
SUBSTANCE: invention can be used for stand tests of pumps of any application. According to proposed method full pressure at pump input is maintained constant by means of reservoir with free surface of liquid exposed to constant (atmospheric) pressure installed in intake pipeline. Working liquid saturated vapor pressure at pump input is changed by heating. Periodical measurement of required parameters in process of liquid heating makes it possible to calculate sought for cavitation margin Δh. Method is implemented by test stand containing pump to be tested, output throttle, flow meter, heat exchanger, service tank, pipe fittings, all arranged in closed hydraulic circuit, and reservoir with free surface of working liquid in combination with capsule made of heat conducting material connected to circuit at pump input. Space of capsule is divided into two parts, one of which is partly filled with working liquid and sealed, and other communicates with circuit.
EFFECT: improved accuracy of measurements and simplified determination of pump cavitation characteristics.
3 cl, 1 dwg
SUBSTANCE: in through portion of pipe with choking of through portion cavitation flow lock mode is set, and in zone of low density value of critical pressure of cavitation and liquid flow are determined, which flow is used to determined liquid speed in pipe neck. Received critical pressure value of cavitation is aligned with pressure of saturated steam of pumped liquid, after that to specially built calculation graph dependencies of relative value of critical pressure of critical speed of flow in channel neck are applied in the moment of setting of lock mode with different concentration of cores target concentration of cores of cavitation of pumped liquid is determined.
EFFECT: higher efficiency.
FIELD: aviation industry.
SUBSTANCE: device helps to get real pattern of liquid pressure distribution which flows about "blown-about" object in water tunnel. Device has driven frequency pulse oscillator, frequency divider, control pulse counter, longitudinal contact multiplexer which connect capacitors with shelves, lateral contact multiplexer which connect the other output of capacitors, matching unit, analog-to-digital converter, indication unit, water tunnel, blown-about object, grid with capacitive detector.
EFFECT: improved precision of measurement.
FIELD: experimental hydrodynamics.
SUBSTANCE: method comprises making a model dynamically similar to the marine engineering structure in mass, sizes, location of the center of gravity, and inertia moment and mounting the model in the experimental tank by means of anchor-type links provided with dynamometers. The device comprises experimental tank and model provided with anchor-type links for connecting with the frame. The anchor-type links are provided with dynamometers and devices for control of initial tension. The frame has flat horizontal base, vertical pillars , and blocks. The base is provided with the members for securing the vertical pillars at specified points of the base. The vertical pillars are provided with blocks and members that are mounted for permitting movement along the pillars and their locking at a given position. The model is provided with the pickups of angular and linear movements. The outputs of the dynamometers and pickups of angular and linear displacements of the model are connected with the input of the computer.
EFFECT: expanded functional capabilities.
2 cl, 3 dwg
FIELD: measuring techniques.
SUBSTANCE: method and device can be used for measurement of hydraulic-dynamic resistance of different surfaces moving in fluid. Time of load descending, which load is kinetically connected with disc rotating in water, is compared when surface of load is coated with different matters.
EFFECT: simplicity at use; reduced cost.
2 cl, 1 dwg
SUBSTANCE: method comprises modeling the process of interaction of water flow with a rough surface by changing the working member of the sloping chute for a precision member with the smooth surface, measuring the height of the water flow in the entrance and exit sections of the chute by means of micrometer with measuring needle, determining the flow rate, and measuring the width of the chute. The smooth member is changed for the working member provided with a rough surface, and the height of the water in the exit section of the chute is measured.
EFFECT: simplified method.
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.
FIELD: the invention refers to experimental hydrodynamics and may be used for definition of the resistance of small objects to a running flow at tests.
SUBSTANCE: the arrangement is fulfilled in the shape of a grate with the width Bt. and the height ht, deepened at the height T formed by rods with a step ▵ fixed in the supporting contour and is located at a certain distance in front of the tested object. At that it is installed with possibility of independent displacement relatively to the tested object and is fastened on the object and/or the body or probably on the bodies moving together with the tested object relatively to the test gondola. It is also may be formed by a system of private turbulators fulfilled in the shape of grates with a different size of cells, with possibility of their independent displacement relatively to each other including the fastening on different bodies and located primary in-series. The private turbulators may be fulfilled in the shape of grates particularly with different main direction of the rods of the grate. The mode is in locating the turbulator in front of the tested object with possibility of independent displacement relatively to the tested object and fastening on the object and/or on the body probably on the bodies moving together with the tested object particularly to test gondola. At that the position of the turbulator relatively to the tested object particularly the distance and displacement relatively to the tested object and also deepening and probably dimensions are chosen on the basis of comparison of results of the trial run of tarring of objects of different scales.
EFFECT: possibility of investigating of small models and revelation of the influence of resistance of the surface of the model.
6 cl, 3 dwg
SUBSTANCE: invention refers to experimental hydrodynamics, hydrodynamics and aerodynamics of airscrew and can be used in shipbuilding and aircraft building. Method includes force field created by airscrew rotation and carrier moving, use of visualising facilities and field structure registration by optical equipment. Thus airscrew rotary speed is established assuming production and stream maintenance of visualising facilities. Field is registered by scanning in two transversely-spaced planes, i.e. horizontal and vertical, in front of, and behind, the airscrew. Thus boundary layer, turbulence areas, increased and decreased pressure areas, airscrew expansion angles, and whole flow structure are showed.
EFFECT: high-accuracy picture of airscrew propeller environment flow.
5 cl, 16 dwg
SUBSTANCE: test stand for amphibious vehicles has basin with entrance and exit ramp, side walls, road, ramp and basin borders. From both sides of exit ramp pits are made in which ends of tubular shaft are embedded. Parallel arms-brackets of sheet metal are attached to the shaft equally spaced from axis. Between attached arms-brackets, spacer pipe is preliminary embedded on shaft which pipe has rectangular pawl with holes on both sides. By means of these holes the pipe is attached to captivating sheet located on symmetry axis of exit ramp. At the end of arms-brackets with lugs, cylinder is attached on axis. This cylinder is made along generator of curve corresponding to curve of vehicle front bumper. Tube rings with pawls are put on shaft ends. The pawls are fixed on pit floors. Spheroidal flanges are fixed on shaft ends to which flanges arms are attached, with brought-out from pits ends having lugs, and pneumatic cylinders are attached to arms from two sides.
EFFECT: reduction of scope of work during test stand construction and provides getting true data about capability of vehicle to move over water surface on tired wheels.