An injection atomization full-field measurement device and method based on photon time-domain filtering technology

Abstract

The invention discloses an injection atomization full-field measurement device and method based on photon time-domain filtering technology. The device consists of a femtosecond laser, a beam splitter, a polarizer, a variable rectangular diaphragm, a beam expander system, Target injector, first convex lens, optical Kerr medium, analyzer, second convex lens, attenuator with variable transmittance and its spatial distribution structure, ICOMS camera, half-wave plate, optical path delayer, first The reflection mirror, the second reflection mirror, the light beam collector, the timing control system and the computer are formed. The invention uses the optical Kerr effect to select ballistic photons for imaging, and then obtains a clear spray field structure diagram; uses a variable rectangular aperture and a beam expander system to shape the beam into a rectangular spot with a variable aspect ratio, effectively covering all Spray field: apply the attenuator with variable transmittance and its spatial distribution structure, so that the number density of ballistic photons reaching the near-field area of ​​the ICMOS camera and other areas is equivalent, so as to obtain a clear full-field image of the spray field at the same time.

Description

technical field [0001] The invention belongs to the field of laser measurement, and relates to a full-field measurement device and method for injection atomization of an engine injector based on photon time-domain filtering technology. Background technique [0002] Liquid fuel (hydrocarbon) has the advantages of easy storage, portability, high density, high calorific value per unit volume, and practical application. It is widely used in ramjet engines, turbine engines, detonation engines, rocket engines, and automobile engines. The injection and atomization process of engine liquid fuel plays a key role in the entire engine working process, and has a very significant impact on engine combustion efficiency, ignition performance and combustion stability. In addition, the design technology of modern engines mainly uses computational fluid dynamics (CFD), but due to the complexity of the combustion process and the lack of experimental data, the CFD model has many shortcomings, o...

AI Technical Summary

Problems solved by technology

Due to the above reasons, there are currently two difficulties in fog measurement. First, for the near-field region, the optical transmittance difference between the center and edge of the spray region is about 10. 2 ~10 5 times, so it is difficult to obtain a clear full-field structure map of the near-field region at the same time during the measurement

Second, due to the large difference in optical transmittance between the near-field area and other areas, the same measurement method cannot be used. At present, different measurement methods are used to measure separately. Violent process, so there is no correlation between the flow field structure in the near-field region and other regions measured by different means

Based on the above problems, the current atomization measurement methods cannot obtain the full-field transient structure of the injection atomization process at the same time, and cannot reflect the real injection atomization process

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