Air suction type fiber bragg grating total temperature probe and measuring system thereof

Abstract

The invention discloses an air suction type fiber bragg grating total temperature probe and a measuring system thereof. The air suction type fiber bragg grating total temperature probe comprises an L-shaped pipeline, a fiber bragg grating sensor, a grating supporting steel pipe and a vacuum pump, wherein the L-shaped pipeline comprises an air inlet channel and an air entraining pipe; a steady flowchannel, a convergence channel, a throat part and an expansion channel are sequentially arranged in the air inlet channel from top to bottom; the air entraining pipe is connected to the lower end ofthe air inlet channel and communicates with the expansion channel of the air inlet channel; the head of the grating supporting steel pipe extends into the convergence channel of the air inlet channel,and the lower end of the grating supporting steel pipe penetrates out of the bottom of the air inlet channel; and the fiber bragg grating sensor is located in the convergence channel of the air inletchannel. During work, the air entraining pipe is subjected to air exhausting through the vacuum pump; the air speed of the convergence channel at the inlet of the air inlet channel is in a relativelyhigh-speed and stable state, and when the convergence section reaches a supercritical state, a local convective heat transfer coefficient around the grating sensor is increased to a stable value andis not influenced by incoming flow static pressure and flow velocity fluctuation, so the temperature measurement speed, the temperature measurement precision and the stability of the total temperatureprobe are improved.

Description

technical field [0001] The invention belongs to the technical field of temperature sensing and measurement, and in particular relates to an air-breathing fiber grating total temperature probe and a measurement system thereof. Background technique [0002] Transient temperature is an important parameter for high-temperature flow field and thermodynamic analysis of temperature-resistant devices in applications such as combustion and high-speed heat transfer. The high-speed dynamic and accurate measurement of transient temperature is of great significance in many fields of defense industries such as aerospace, gas turbines, and missile explosives. critical use. For example, in the development of aero-engines, it is necessary to conduct high-speed dynamic tests on the airflow temperature at the inlet outlet, between rotor stages, etc.; in the research of weapons such as missile gas jets, ammunition explosions, and inner and outer walls of gun barrels, transient temperature tests...

AI Technical Summary

Problems solved by technology

Among them, fiber bragg grating temperature measurement technology has been widely used in conventional temperature measurement occasions, but in the above special test occasions, its own structure and the structure of the total temperature probe using it as a temperature sensing element cannot adapt to high-speed dynamic The demand for stable temperature measurement in the temperature field must be improved in order to meet the requirements

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