Interferometric Rayleigh scattering velocimeter for flow field

Abstract

The invention discloses an interference Rayleigh scattering speed measurement device used for flow fields. The interference Rayleigh scattering speed measurement device comprises a laser, a flow-field interaction unit, a scattered light collection unit, a reference unit and a detection unit; the flow-field interaction unit comprises a half-wave plate and a focusing lens which are sequentially arranged along an outgoing light path of the laser, a detection point is arranged on the outgoing light path of the laser and close to the focal point of the focusing lens, the flow fields to be measured flow through the detection point, and the flow-field direction and the laser outgoing direction are arranged in an inclined mode; the scattered light collection unit is a lens set which is arranged in an inclined mode as for the flow-field direction; the reference unit comprises an incoming beam splitter, a reflector and an outgoing beam splitter, and the detection unit comprises a Fabry-Perot etalon and an ICCD camera which are arranged along a scattered light path. According to the interference Rayleigh scattering speed measurement device, by simultaneously measuring relative frequency shift between static reference light interference rings and flow-field scattered light interference spots, real-time frequency shift signals are obtained, influence on frequency shift detection from output wave length jitter of the laser is eliminated, and the interference Rayleigh scattering speed measurement device is suitable for the majority of diagnosis flow fields comprising a combustion flow field.

Description

technical field [0001] The invention relates to a flow field velocity measurement device, especially an optical measurement device suitable for high-speed flow field velocity measurement of engines, wind tunnels and the like. Background technique [0002] Using laser-based non-contact optical diagnostic technology to diagnose the combustion flow field of various engines such as aeroengines and internal combustion engines, obtain various parameter information of the flow field, optimize the design of the engine and verify the simulation model, improve combustion efficiency and engine performance, and Pollutant discharge control and other aspects have very important scientific significance and practical value. [0003] Among the diagnostic parameters of engine combustion flow field, temperature and velocity are the two most basic parameters. Through the measurement of flow field static temperature and velocity, the total temperature of flow field can be calculated and informat...

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Problems solved by technology

[0007] The technical problem to be solved in the present invention is to develop a speed measuring device based on the interference method to detect the Doppler frequency shift of scattered light on the basis of Rayleigh scattering technology, so as to solve the problems of weak signal, vibration influence, laser output wavelength jitter, etc. in engineering applications. question

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