A continuous supersonic sand erosion test bench and test method

Abstract

The invention discloses a continuous supersonic sand erosion test table and a test method thereof. The test table comprises a gas source device, a screw sand supply device, a sand blasting device, a test chamber, an exhaust tube and a cyclone separator. The gas supply device obtains high pressure gas flow through a high pressure gas storage tank, the screw sand supply device adopts a pressure container as a sand storage container, a motor drives a screw to rotate at a uniform speed, and the gas outlet of a feeding cylinder is provided with a gas flowing hole for assisting sand falling in order to avoid sand grain obstruction; and high quality gas flow is obtained from the Laval tube outlet of the sandblasting device to make the sand grains move along the axis in order to reduce sand grain and tube wall collision. The sand grains can be accelerated to a supersonic state only through room-temperature drying gas; the sand supply device has a good sealing property, can balance the pressure of the sand supply device in a high pressure environment, and has a good sand supply precision; and a gas source used in the invention has a low price and stable performances.

Description

technical field [0001] The invention relates to the field of fine particle transportation and powder transportation under pressure environment, and also relates to the field of sandblasting test. Background technique [0002] So far, according to published literature, there is no equipment that can continuously spray sand particles to a designated target at supersonic speed through normal temperature gas. To achieve the goal of cold-state continuous supersonic erosion, several interlocking technical problems are faced: first, how to accelerate sand particles to a supersonic state through normal temperature gas. To make the sand particles reach the supersonic state, the high-pressure gas (the pressure value is usually set above 3MPa) should be fully mixed with the sand particles in a low-speed environment, and then the gas-sand two-phase flow with a certain pressure should pass through the Laval structure tube. (Shock tube) accelerated to the supersonic state required for th...

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Problems solved by technology

This method has some disadvantages: first, the device cannot realize continuous erosion

The test device needs to re-place the material and re-inflate the shock tube every time the erosion test is carried out. It belongs to the intermittent test device and cannot achieve the purpose of the test and research of continuous feeding erosion.

Second, the safety and test efficiency of the device are not high

Due to the dispersion of the performance of the aluminum film material, if the aluminum film is not breaking, it will bring safety hazards to the test personnel; because the device uses intermittent work, it takes a certain amount of time to place the materials and materials for each test. Inflating the shock tube affects the test efficiency and increases the labor burden of the test personnel

Thirdly, it is very difficult for the device to make the sand particles reach the supersonic state

The disadvantage of this method is that: the ejected high-temperature flame will inevitably affect the test piece eroded by sand particles; the high-temperature flame continuously acting on the metal test piece will greatly reduce its structural strength, making Sand particles are more likely to cause damage to the surface of the eroded material, so that it cannot reflect the erosion resistance of the material

This method has some deficiencies: first, the device cannot realize supersonic erosion of sand grains

The device does not use a Laval tube to accelerate the gas-sand two-phase flow, but uses an ordinary flat nozzle; according to the relevant knowledge of fluid mechanics, when the air velocity is infinitely close to the speed of sound, the gas flow per unit area reaches the maximum; For straight pipes, the congestion effect has already been formed at this time, and the gas flow in the downstream of the pipe is absolutely impossible to be smaller than that in the upstream, so no matter how much pressure the airflow in the straight pipe has, it cannot achieve supersonic speed.

Second, if a compressor is used as a supersonic gas source, the cost will be too high

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