Dynamic pressure probe and method for measuring high temp jet dynamic pressure by the probe

Abstract

The invention discloses a dynamic pressure measuring probe and a method for measuring high temperature jet dynamic pressure by this probe. And it comprises a water cooled conical pressure probe and pressure sensor, where the water cooled conical pressure probe comprises outer tube whose head is made with sampling hole and whose center is provided with water-air isolating tube, the interacvity of the water-air isolating tube is formed with an airflow channel and a cooling water channel is formed between the water-air isolating tube and outer tube, the tail end of the outer tube is connected with the pressure sensor, the sensing surface of the pressure sensor corresponds to the airflow channel, and the pressure sensor is connected in turn with amplifier and signal collection system by signal lines. And the invention reduces inlet water pressure requirements and reduces measuring cost, and can conveniently and quickly obtain dynamic pressure distribution on jet cross section, largely reducing measuring time.

Description

technical field [0001] The invention relates to a dynamic pressure measuring probe and a method for measuring high-temperature jet flow pressure with the probe. Background technique [0002] As a high-energy beam with high temperature and high enthalpy, thermal plasma jet has been widely used in the fields of aerospace, mechanical processing, metallurgy, chemical industry and bioengineering. The parameters such as temperature and velocity of thermal plasma jet characterize its Important parameter of flow characteristics. Deriving the jet velocity from the measured jet temperature and dynamic pressure data is a commonly used velocity measurement method. The temperature of the plasma jet is generally in the range of 3000-15000K, and the conventional measurement of the dynamic pressure of the thermal plasma jet is generally carried out through the cooperation of the water-cooled pitot tube and the U-shaped tube (or micromanometer), which belongs to the contact measurement meth...

AI Technical Summary

Problems solved by technology

The general Pitot tube is made of an integral structure from the head to the tube body and the Pitot tube support. The head of the Pitot tube is circular, and the cooling water must flow near the head of the Pitot tube, and a dead zone of water flow cannot be formed at the head. , otherwise the pitot tube will be burned out; since the pitot tube pressure measurement is a contact measurement method, it will disturb the measured airflow

In order to reduce the disturbance of the measured air flow, the size of the pitot tube should be reduced as much as possible, so the passage of water in and out is very small, and a high-pressure water pump is required to pressurize the cooling water entering the pitot tube, so as to increase the water flow rate to ensure the cooling effect; Although reducing the size of the pitot tube is the most effective way to reduce the disturbance, however, the special processing technology will increase the price of the pitot tube, making it unaffordable for ordinary buyers; the maximum temperature of the plasma jet often exceeds 10,000 degrees, especially Especially when the gas with high thermal conductivity such as hydrogen is added to the jet gas, the use of the pitot tube needs to be particularly careful, otherwise the head of the pitot tube may be burned and the pitot tube will be scrapped as a whole, which also limits the practical use of the pitot tube. Attempts to use range

At the same time, because the inherent vibration period of the U-shaped tube is very long (on the order of seconds), it cannot respond quickly to the jet flow pressure signal

Therefore, in order to measure the accurate signal of the jet flow pressure, the pitot tube needs to be placed in the high-temperature jet for a long time, which also accelerates the ablation of the pitot tube head to a certain extent, thereby shortening the service life of the pitot tube

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