CFD Simulation And PIV Test Of Soy Protein Liquid Spray

With the continuous innovation and development of the country,people life have also been improved,and people consumption concept has also changed.The packaging of products requires not only exquisite but also environmental-friendly.However,at present,most of them are still using petroleum based packaging materials as food packaging materials.There are many problems with the use of petroleum based packaging materials.For example,this material is difficult to degrade naturally and can not be recycled and so on.The overuse of packaging materials is a huge consumption of non-renewable energy such as oil,and the garbage produced by the consumption has also caused serious pollution to people living environment.Therefore,the research and development of environmental-friendly and edible packaging materials has been strongly advocated by the country.Vegetable paper with rich raw material sources,natural degradation and can be regenerated has been favored.However,due to the fact that the general pure vegetables are relatively brittle on paper and do not possess heat sealing properties,so they cannot be directly used as packaging materials.The research team of this project proposed that a composite film be formed by spraying the soybean protein liquid on the pure vegetable paper.The vegetable paper has certain heat sealing property.In order to develop a better spray coating of soybean protein solution,it is very important to study the velocity field of spray particles of soybean protein liquid spray.The main contents of this paper are as follows:Firstly,according to the working principle of the nozzle,the composition and principle of the test system PIV(Particle Image Velocimetric)are introduced briefly.Secondly,in this paper,the spray velocity field of soybean protein spray is simulated by using CFD(Computational Fluid dynamics)numerical simulation and establishing appropriate mathematical and physical model.The atomization morphology of the velocity field of soybean protein spray particles was studied by theoretical analysis,and the simulation results were compared with the actual spray atomization state.Finally,the spray field is measured by PIV technique,and the distribution of atomization velocity field is obtained.The influence of different spraying parameters on the velocity field of atomized particles is analyzed.By comparing and analyzing the velocity field of atomized particles simulated by CFD in the section of PIV,the accurate mathematical model of atomization and the experimental data are obtained.The results of the study are indicated as below:(1)the velocity of spray atomized particles of soybean protein liquid increases first and then increases with the increase of spray pressure,while the velocity of particles increases first and then decreases when the spray flow rateincreases.With the increase of spray hydraulic pressure,the velocity of spray atomized particles has a tendency to increase slightly.(2)under the condition that the viscosity of soybean protein solution and spraying parameters are not changed,The variation law of atomizing particle velocity in the direction of the center axis of the nozzle and the different sections perpendicular to the central axis of the nozzle is analyzed: the velocity of the atomized particle in the direction of the axis of the nozzle increases first and then tends to stable with the increase of the distance from the nozzle;In the section perpendicular to the central axis of the nozzle,the velocity of the atomized particles is larger than that of both sides,and the law of symmetry is basically presented.(3)Finally,by comparing the PIV test results with the CFD theoretical simulation results,The experimental results are consistent with the simulation results,and the maximum error is 9.46%.Thus,reliable experimental data and theoretical model were obtained,which laid the foundation for better analysis of even and consistent vegetable coincidence film.