Method for automatically identifying diesel spray crushing process and automatically realizing spray continuous calculation

Abstract

The invention discloses a method for automatically identifying a diesel spray crushing process and automatically realizing the spray continuous calculation. The method automatically judges the processthat a liquid film is crushed into liquid drops in the diesel injection process, and realizes a SD-ELSA algorithm of the spray continuous calculation. The SD-ELSA algorithm is characterized in that the sphericity degree and the average particle diameter of liquid phases in grids are calculated and taken as judgment bases, the information of particles in a flow field are calculated through a Lagrangian method, the information of the grids belonging to continuous liquid phases in the grid node information in the full-flow field is calculated by using an Euler model, and Euler block masses meeting two bases for determination are converted into particles and re-calculated through the Lagrangian method. According to the method, dynamic converting coupling of the Euler-Lagrangian model is realized, the complete information of discrete phases and continuous phases in the flow field can be automatically obtained and subjected to iterative computation, three stages of a liquid column, primarycrushing and secondary crushing of the diesel injection are obtained, and the diesel spray process is completely represented.

Description

technical field [0001] The invention belongs to the research field of diesel engine spray characteristics and relates to a simulation calculation method of spray characteristics. Background technique [0002] The high-pressure diesel oil enters the cylinder of the diesel engine through the nozzle jet flow. During the jet flow process, the diesel oil will firstly form a liquid film on the periphery of the liquid column from the continuous liquid column state at the outlet, and further develop with the jet flow, the liquid film breaks and begins to produce droplets. These The droplets are further broken and developed, and finally atomized. This is a process along the direction of the jet, where there is a continuous liquid phase region, a transition region where the continuous phase and the discrete phase are mixed, and a full droplet region where all the discrete phases are present. The cost of existing optical testing methods is high, and simulation calculation simulation i...

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Problems solved by technology

The current research has begun to combine the Euler and Lagrangian methods. By pre-defining a certain spatial position in the direction of the injection, it is assumed that the region is a mixed region of the continuous phase and the discrete phase. Rafa, the Lagrangian method is used in this area, that is, the ELSA method, but this method first determines that the accuracy of the mixed space has a great impact on the calculation accuracy, and cannot dynamically change the position of the interval, so it is not suitable for current applications. Changes in working conditions when conditions such as injection pressure change

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