Method and device of assembly for inspecting hydraulic-dynamic resistance

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

 

The invention relates to the field of measurement of the hydrodynamic resistance of the various surfaces of objects as they move in a fluid.

Known rotary setup for the study of hydrodynamic resistance used to determine the friction lining of the vessel (As the USSR №894396, CL G 01 M 10/00, 63 In 9/02, 1980; A.S. USSR №938060, CL G 01 M 10/00, 1980 - prototype). The prototype contains a water tank, the test sample in the form of a disk mounted on a vertical shaft associated with the motor. The system has sensors torque motor, and its speed.

During the test, measurements are made of the torque motor, and its speed. Then, the calculations for the evaluation of hydrodynamic resistance of the sample.

The disadvantages of such mechanisms is the need to use special expensive equipment (motors, sensors, power and speed). In addition, the accuracy of the results depends on the quality of the sensors and the degree of influence of additional interference (friction in the bearings, the volume and the surface of the tank and others).

Currently, there are significant opportunities to reduce resistance to movement of bodies in water by drawing on their different surface coatings. Conducting a full guide is dinamicheskih tests to verify the intended effect is expensive. Therefore, before conducting such experiments, it is necessary, at least at a qualitative level, to ensure the existence of the effect.

The technical result of the method is a simplification of the production of technical measurements. It is achieved by the fact that the experiment is conducted in exactly the same conditions for the test samples, and the effect of reducing resistance is estimated by the testimony of only one unit - stopwatch.

The technical result of the device - to provide a simple and cheap setup for Express-analysis on the qualitative assessment of the impact of coatings on reducing the hydrodynamic resistance to movement of the body in the water. It is achieved by the fact that in the known device containing a reservoir for water, the test sample is mounted on a vertical shaft, instead of the motor system is used cargo, mechanically connected with a vertical shaft and providing its rotation.

The proposed device (drawing) includes: disc 1 mounted on a vertical shaft 2, a water tank 3, the main burden of 4 and an auxiliary load 5, the stopper 6 and the flexible cable 7.

Disc 1 is the test body. It can be a reference (uncoated) or experimental (coated). The shaft 2 has a transition energy of motion of the load 4 in the rotational movement of the disc in the water. The headband is positive load 5 carries out the initial tension of the cable, excluding its slippage on the shaft 2. The stopper 6 records the initial position of the system: the main burden of 4 raised to the maximum height, auxiliary load 5 is folded down and secured. Flexible cable provides transmission main cargo 4 to the shaft 2 with the disk 1.

The essence of the experiment is to measure the time the motion primary cargo 4 from its upper initial position to the bottom. However, given that the weight and dimensions of discs 1 reference and experimental inertial properties of all the moving parts of the installation, as well as the work done by the load is the same, the difference in time of movement of the load 4 when using the reference and experimental disks indicates the change in resistance value. Thus, the hydrodynamic resistance to movement of the disk in the water judge by time lowering, causing the disk to rotate.

Of course, that the results of this experiment can be only qualitative in nature, as to consider the impact of contextual factors is not possible, for example the effect of the walls of the tank (3) of the rotating fluid friction in the bearings and others. At the same time sustainable difference greater than the statistical error of the experiment, the time measurements of the movement of cargo ensures the effect of the ISM is in hydrodynamic resistance to movement of the disc in the water.

We offer installation and use are very simple and cheap tool for qualitative assessment of the influence of coatings on reducing the hydrodynamic resistance to the movement of bodies in water.

1. Method the study of hydrodynamic resistance in the movement of bodies in water, consisting in the measurement of friction forces acting on the rotating disk, characterized in that the hydrodynamic resistance to movement of the disk in the water judge by time lowering, causing the disk to rotate.

2. Device installation for implementing the method of the study of hydrodynamic resistance according to claim 1, consisting of a disc in the tank of water, a vertical shaft, wherein rotation of the test drive in the water is performed by using the primary and secondary loads, capable of moving in a vertical position at a certain distance, flexible cable, ensuring the transfer of the translational movement of cargo into rotational motion of the disk.



 

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