Device and method for measuring liquid jet on outermost boundary

Abstract

The invention discloses a device and a method for measuring liquid jet on an outermost boundary. The device comprises a computer, a camera, a test section and a laser generator, jets are injected in the test section, laser sheet-light emitted by the laser generator irradiates on jet droplets, a focal plane of the camera, the laser sheet-light and an observing plane are on a same plane, the camera is used for shooting droplets in a laser plane, a camera shooting face and a laser sheet-light incident plane are transparent, the measuring device is disposed in a darkroom environment, and the computer collects shot images and binarize the images to obtain a jet boundary figure and calculates physical boundary distance information of the jet boundary figure. The method includes: A, demarcating the measuring device; B, utilizing the camera to shoot the droplets, and obtaining image results; C, converting the image results into a grayscale map, and extracting a boundary; and D, calculating the physical distance information of the jet boundary. By the device and the method for measuring liquid jet on the outermost boundary, quantitative information of the droplets, formed after the liquid jets are crushed, on the outermost boundary in a whole flow field observing plane, can be obtained.

Description

technical field [0001] The invention relates to the fields of optical measurement methods and image processing, in particular to a measurement device and method for obtaining the outermost boundary of a liquid jet. Background technique [0002] Fragmentation and atomization of liquid jets is a very important process in liquid fuel propellant engines. When studying the injection and atomization characteristics of the jet, the distribution of the droplets formed after the jet is broken is a very important measurement parameter, which determines the atomization of the liquid jet and its mixing degree with the airflow. The outermost boundary of the jet is the outer boundary of the largest area that the droplets formed after the jet breaks can reach. [0003] The maximum expansion range of the liquid jet is expressed in the transverse air flow as the penetration depth of the liquid jet. In the study of the liquid jet breakup and atomization process in the cross flow, the litera...

AI Technical Summary

Problems solved by technology

The Canny method used in the image processing process has large human factors and uncertainties, and the selection of the threshold value of the gray gradient has a great influence on the determination of the jet boundary; at the same time, due to the uneven concentration distribution of the droplets, the sheet light In the image results obtained by the Canny method, the gray distribution is not uniform, and the pixel point corresponding to the maximum value of the gray gradient is not necessarily on the peripheral boundary of the jet, but may be on the boundary point between the dense liquid mist and the thin liquid mist, so the Canny method can be used to obtain The boundary result of the jet is not necessarily the outermost boundary of the jet; in addition, the physical meaning of the jet boundary obtained by using the Canny method to process the sheet light image is not clear enough

[0007] In general, there are currently many methods for obtaining the boundary of the liquid jet in the airflow, but it is difficult for these methods to obtain the outermost boundary of the jet. At the same time, different digital processing methods are used to process the obtained image results to obtain endless jet boundaries. are the same, and some observation methods are inefficient, it is urgent to develop a fast, efficient and quantitative research method to obtain the outermost boundary of the jet

Images