The Regime Of Breakup And Atomization Of Viscous Liquid Jets

The breakup and atomization of liquid jets is of theoretical importance and has been widely used in engineering, especially, in diesel engines and gas turbines etc. The injection, atomization and mixing of fuel with the ambient gas oil has essential effects on the combustion processes. A good atomization is an essential prerequisite to promote efficient combustion, and is of significant meaning in saving energy and reducing the environment pollution. This thesis conducts a study on the mechanisms of the breakup and atomization of viscous liquid jets, the following terms has been finished.1. A detailed review of the previous works on the stability analysis of liquid jets and it's breakup and atomization is given.2. This thesis extends the former works on the stability of liquid jets in such a way that the stability of viscous liquid jets in the case of 3-D is considered. The characteristic equation is obtained which delineates the evolution of a general 3-dimensional disturbance on the free surface- of an incompressible viscous liquid jet, then by combining the complex analysis with the real analysis in multivariables, the existence and uniqueness of the solution of the characteristic equation has been proven. The manually deduced characteristic equation has been verified by means of the computer algebra software MATHEMATICA.3. Comprehensive theoretical investigations and numerical analysis have been carried out, and so as a certain number of operating mode. Both of the evolution of disturbances on the free surface of a liquid jet and it's relative intensity are applied to analyze the mechanic regime of and difference between the breakup and atomization. Here, a new dimensionless parameter Je=We/O is introduced as a criterion to distinguish between the breakup mode and atomization mode. Then a unified theory about the breakup and atomization of viscous liquid jets has been proposed based on the linear theory.4. By combining numerical results and theoretical analysis with the measured spray characteristics of liquid jets, formulas are established to compute the spray angle and breakup length by means of the regression analysis. Some experiments have been done to gain information of the characteristics of...