SU901873A1 - Plant for investigating material cavitation stability - Google Patents

Description

The invention relates to hydrodynamic tests, in particular to devices for the study of the cavitation resistance of materials.

A known apparatus for examining cavitation resistance of materials, comprising a cavitator mounted in a cavitation tube and kinematically connected to a drive, as well as a reference node for the sample, positioned behind the cavitator 11.

The drawbacks of the known setup are the long research time, the low accuracy of the test results and the narrow range of modes under study.

The purpose of the invention is to reduce research time, improve the accuracy of test results and expand the range of modes under study,

The goal is achieved by the fact that the reference assembly of the sample contains a streamlined profile made of the nose, middle and core: —You are located in a cavitation pipe in a plane parallel to its axis, and the middle part of the streamlined profile is provided mounted on its side wall clamp for the sample and mounted to move the s. plane of the opposite direction of the cavitation pipe, and the latter is made with a cut-out, tightly sealing YIO to the perimeter of the wall of the middle part of the streamlined profile, The cavitator is mounted so that it can be installed in the nose of the streamlined profile.

The drawing shows the proposed installation, the side of the project.

The installation contains a cavitation pipe 1 located in one of the windows of the working section and a supporting unit for sample 3, mounted on a sealed base 2, containing a symmetrical streamlined profile 4 arranged in a plane parallel to the axis of the pipe 1 and consisting of a screw 5 of the middle part — the plate 6 installed with the ability to move in said plane across the pipe 1, the bow 7 and the aft part 8. In the side wall, the bow 7 of the profile, a slot 9 is made. The test sample 3 is mounted on the outer the side wall of the middle part - the plate 6 behind the slit 9 with the help of a clamping clamp (not shown) is flush with the surface of the middle part - the plate 6. The cavitator - the blade 10 is placed in about 15

7 with the ability to exit into the flow through the slit 9 and mounted rotatably on a shaft (not shown) of the electric drive 11. The pipe 1 is made with a cut-out covering the window in the zone not tightly around the perimeter of the wall of the middle part - the flow-profile 6 shown). There is also a slit on the other side of the streamlined profile, a cavitator sample (not shown). The installation works as follows. Screw 5 rotates the plate 6 out of the pipe 1 and on the outer lateral wall of the plate 6. The test specimen 3 is very rigidly fixed with its surface with a clamp by clamping. Then the screw 5 moves through the screw 5, that 6 extends into the pipe 1, B The pipe 1 is set to the mode (flow speed, discharge) according to the test program, the electric drive 11 is turned on and the required number of revolutions is selected. The electric drive 11 drives the cavitator blade 10 to rotate, while they rotate at the same speed, but in different directions. Rotating, cavitator 10 periodically enters the flow through the slit 9 and forms cavitation cavities in it, which are carried away by the flow and collapse on the test sample 3, the tests are performed for a predetermined period of time. After that, the electric water 11 is turned off, the plate 6 is pushed out of the pipe 1, the test sample 3 is removed and raised. Then, a new test cycle is repeated. To adjust the cavitation volume. The cavity cavity is equipped with

leads to the expansion of the range of the studied: recimes and to an increase in the intensity of the cavitation effect, and, consequently, to diminutive cavitators with different widths. In addition, the axis of rotation of the cavitator can be set inclined to the direction of movement of the middle part at an angle, and to the direction of flow - at an angle j3b 90-ol. The oC angle can take values from 0 to 90. The presence in the installation of a streamlined profile allows the cavitator to be mounted for rotation. With the rotational inertialess motion, a greater frequency of oscillations of the cavitator can be achieved. Will increase the frequency of the oscillation of the cavitator, the time required for the destruction of the sample. Performing the middle part of the streamlined profile moving in the direction perpendicular to the flow makes it possible to freely extend it from the cavitation tube and change test specimens located on the side wall of the middle part, without draining the water, and this, in short, significantly reduces the time to prepare for test. Reducing the time required to destroy the specimen and the time required to prepare for the test shortens the test. Changing the test samples without draining the water allows testing under constant conditions of a constant fluid (water), which eliminates the error in setting the mode in the cavitation tube (flow parameters) and increases the reliability of the test results. Thus, tests on the proposed installation are carried out in JO-15 times faster, while the reliability of the results increases, In the installation, the range is expanded (by the number of Struttings (1x hal modes) due to the increase in cKoiSocTb and cavitator length rotated with the possibility of rotation, and the flow rate at which the cavity is formed decreases, since the cover y in the proposed installation can be obtained at a flow rate in the pipe equal to zero.

Claims (1)

1. Georgievsk, E.L. Cavitational erosion of propellers and methods of dealing with it. L., Shipbuilding, 1970, p. 15 (prototype).