Device for simulating hypersonic speed condensation process in spray pipe and diagnosis method

Abstract

The invention discloses a device for simulating a hypersonic speed condensation process in a spray pipe and a diagnosis method. The device comprises a simulation spray pipe device and a measurement system, the simulation spray pipe device comprises a test section (1), a connection section (9) and a vacuum section (11); and the measurement system comprises a TDLAS measuring system, a pressure measuring system and a high-speed photographing system. The device is based on the sparse wave principle, the sparse waves are reflected on the wall surface and the gas contact surfaces of the high-pressure section and the low-pressure section, so that the pressure at the position of a measuring point is continuously reduced, the degree of supercooling is increased, and substances are condensed, and the device ensures the uniformity of a flow field of a test section; and meanwhile, the hypersonic speed condensation process of the substance is realized in a relatively small time scale (less than 1ms). The measurement method is based on the TDLAS measurement principle, and adopts multi-laser signal coupling and a novel baseline fitting method, so that the measurement diversity is ensured, and the time resolution is 100kHz and above.

Description

technical field [0001] The invention relates to the field of hypersonic coagulation of substances, and particularly designs a device and a diagnostic method for simulating the hypersonic coagulation process in a nozzle. Background technique [0002] In a combustion heating wind tunnel, whether hydrogen fuel or hydrocarbon fuel is used, there is water vapor in the product. Before the product gas enters the wind tunnel test section through the equipment nozzle, the temperature drops due to the rapid expansion of the gas along the nozzle expansion section. , may cause rapid condensation of water vapor in the combustion products. At the same time, when the airflow passes through the compression surface of the tested engine, the temperature and pressure suddenly rise due to the shock wave compression, which may cause the condensed water droplets to re-evaporate and other phase transition phenomena. According to the existing literature, the condensation phase change of water vapo...

AI Technical Summary

Problems solved by technology

However, when using TDLAS technology to measure the key parameters of the flow field, the method of multi-laser parallel measurement is often used. This method requires the use of multiple measurement channels, and at the same time cannot effectively synchronize the measurement results, and the processing process is very complicated.

However, the current baseline fitting method used in TDLAS signal processing requires a long baseline at both ends of the absorption signal. However, due to the limited output wavelength of the laser, under high temperature and high pressure conditions, the broadening of the absorption line is similar to the output wavelength of the laser. , the current baseline fitting method cannot obtain an effective baseline. At this time, the laser output wavelength can only be increased by reducing the scanning frequency, which limits the time resolution of the measurement to generally below 10kHz

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