Full-field injection atomization measurement device and method based on photon time domain filter technique

Abstract

The invention discloses a full-field injection atomization measurement device and method based on a photon time domain filter technique. The device comprises a femtosecond laser, a beam splitter, a polarizer, a variable rectangular aperture, a beam expanding system, a target injector, a first convex lens, an optical kerr medium, a polarization analyzer, a second convex lens, a transmittance and spatial distribution structure variable attenuator, a ICOMS (Intensified Complementary Metal Oxide Semiconductor) camera, a half wavelength plate, an optical path time delayer, a first reflecting mirror, a second reflecting mirror, an optical beam collector, a sequential control system and a computer. Ballistic photons are selected according to an optical kerr effect for imaging, and a clear spray field structure picture is further acquired; the optical beam is reshaped to rectangular light spots with variable length-width ratios by adopting the variable rectangular aperture and the beam expanding system, and all the spray field is effectively covered; the density of ballistic photons entering a near field region of the ICOMS camera is identical to that of the ballistic photons entering other regions due to the adoption of the transmittance and spatial distribution structure variable attenuator, so that a clear full-field image of the spray field is acquired.

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...

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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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