Arc heater water leakage detection system based on laser absorption spectrum

Abstract

The invention relates to an arc heater water leakage detection system based on a laser absorption spectrum. A signal generator generates two beams of sawtooth signals and respectively transmits the same to two laser controllers, two beams of laser signals output by the two lasers are coupled and combined into a beam of laser signal by a single mode fiber coupler, collimation and three-dimensionaldisplacement adjustment are performed on the laser signal by a transmitting end of optical adjustment unit, the collimated laser signal passes through supersonic airflow at the outlet of an external spray pipe, the laser signal passing through the supersonic airflow is focused by a receiving end of optical adjustment unit on the other side and is transmitted by a multimode fiber to a detector to perform photovoltaic conversion, so that the laser signal is converted into an electrical signal, and the electrical signal is sent to a data collection and analysis terminal; and the data collection and analysis terminal directly performs collection and real-time analysis on the electrical signal to obtain a spectral absorption signal thereof, and the data collection and analysis terminal processes the spectral absorption signal to obtain an H2O content in the supersonic flow, and performs water leakage judgment on an external arc heater based on a specific value of the H2O content.

Description

technical field [0001] The invention relates to an electric arc heater leakage diagnosis system based on laser absorption spectrum, which is used in the ground simulation test of the electric arc heater, using H 2 O double-line laser absorption spectrum to measure the water content of the airflow at the outlet of the arc heater nozzle, determine the water leakage of the arc heater, and stop in time to provide guarantee for the safe operation of the arc heater. It belongs to the research field of aircraft ground aerodynamic thermal test. Background technique [0002] The arc heater is an important test platform to study the aerodynamic thermal protection of the aircraft. It generates high-temperature airflow through arc heating, simulates the enthalpy and heat flow parameters during the reentry process of the aircraft, and conducts ground test research on the thermal protection system. The high enthalpy, high heat flow, and high pressure environment faced by the arc heater f...

AI Technical Summary

Problems solved by technology

[0003] For a long time, there have been few public reports on the fault diagnosis of arc heaters. Artificial neural network training is used abroad. The results show that the trained model can predict the arc voltage of normal startup and operation of arc heaters under various conditions. By comparing and predicting Values ​​and measurements, it is possible to find some abnormal phenomena before the arc heater is damaged

This method cannot directly respond to all water leakage conditions of the arc heater, and there are cases of false triggering or leakage

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