A method for automatic identification of diesel spray breaking process and automatic realization of spray continuous calculation

Abstract

The invention discloses a method for automatically identifying the diesel spray breaking process and automatically realizing spray continuous calculation, thereby automatically judging the process of liquid film breaking to liquid droplets in the diesel spray process, and realizing the SD-ELSA algorithm for spray continuous calculation. The SD-ELSA algorithm is based on the calculation of the sphericity and average particle diameter of the liquid phase in the grid, uses the Lagrangian method to calculate the particles in the flow field, and uses the Euler model to calculate the grid node information in the full flow field. For the grid of continuous liquid phase, the Euler clumps that meet the two criteria are converted into particles and recalculated by Lagrangian method. This method realizes the dynamic conversion coupling of the Euler-Lagrangian model, can automatically obtain the complete information of the discrete phase and the continuous phase of the flow field and perform iterative calculations, and obtain the liquid column, primary crushing and secondary crushing of the diesel jet flow. stage, fully expressing the process of diesel spraying.

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...

AI Technical Summary

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

Images