High-enthalpy shock tunnel total temperature measurement method

Abstract

The invention discloses a high-enthalpy shock tunnel total temperature measurement method and belongs to the technical field of wind tunnel tests. According to the invention, the sound velocity of theplenum gas is measured through the photoinduced transient grating spectrum technology, and then the temperature, namely the total temperature, of the plenum gas of the high-enthalpy shock tunnel is calculated through numerical iteration according to the plenum gas pressure of the high-enthalpy shock tunnel and the chemical equilibrium theory.

Description

technical field [0001] The invention relates to a method for measuring total temperature in a high-enthalpy shock wave wind tunnel, belonging to the technical field of wind tunnel tests. Background technique [0002] High-enthalpy shock tunnels have been widely used in the research of high-temperature gas effects and high-Mach number scramjet engines, but are affected by high-temperature gas effects, that is, the molecular vibrations and Physical and chemical phenomena such as air dissociation and ionization lead to large changes in the composition and thermodynamic parameters of the test gas, making it difficult to accurately determine the simulation parameters, especially the total temperature can only be estimated by indirect means. [0003] At present, there are two methods for obtaining the total temperature in shock tunnel simulation. One is to obtain the movement velocity of the shock wave in the shock tube by measuring the pressure change along the wall surface of t...

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Problems solved by technology

Due to the obvious attenuation of the shock wave in the shock tube, and the limitation of the number of pressure sensors and the space at the end of the shock tube, this method of estimating the total temperature based on the shock wave velocity has a large error, and does not change with time, so it cannot reflect the expansion. Interference effects such as waves

Another method is to calculate the total temperature through the heat flow of the ball head, which also has a large error. On the one hand, due to the effect of high-temperature gas, the velocity, pressure, temperature and composition of the incoming air in the wind tunnel cannot be measured; The heating and dissociation of the flowing air through the bow-shaped shock wave of the ball head produces radiation heat transfer and surface catalytic effect, which makes the heat flow of the ball head change greatly, making the heat flow calibration method of the ball head almost unusable; in addition, the accuracy of the heat flow sensor itself is not enough.

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