Fundamental Study On The Fluid Flow Analysis Using Field Synergy Principle

At present, plenty results of the fluid flow field can be derived with the Computational Fluid Dynamics, such as the velocity, pressure, streamline and so on, which can provide visible and useful assistance on analysis of the flow process and optimization of fluid solid coupling. But further mathematical analysis methods or models on handling of fluid datas are still lack, the fluid solid coupling and optimization on the fluid mechanics greatly depends upon the experience and professional capacity. At the same time, there exists many innovative methods on the fluid flow drag force reduction, however, the quantitative analysis are less. In this paper, motivated by the field synergy principle on convective heat transfer, through the study on the relationship between the total forces and velocity of fluid particle, the coupling of velocity and velocity gradient are set up. The field synergy model of fluid flow is provided, by which a new theory and numerical tool on the solid fluid coupling is suggested.1) Motivated by the ideal of the coupling of temperature gradient field and velocity field, relationship of the angle of the velocity between velocity gradient of a fluid particle and its dynamic status is studied, and the definition of Synergy Angle is suggested.2) Through derivation on the fluid dynamic equations, the physical definition and mathematical expression of Synergy Angle is provided. Based upon the Synergy Angle, the fluid flow dynamic equations (Navier-Stokes equations) and mathematical analysis, the fluid analysis model based on the fluid flow synergy is derived, during which the Fa we average model was used to take the place of time average. With the Synergy Angle and analysis models, the synergy analysis models are simplified, under incompressible laminar, compressible laminar and incompressible turbulent flow conditions which are classified with Re number. And these three typical flows can be analyzed and optimized using those simplified Synergy analysis models.3) In order to directly provide the feasibility of Synergy analysis models and evaluation on the optimization, numerical simulation and analysis on two laminar and one turbulent incompressible flows were adopted. The original data of the fluid field is obtained by computational fluid dynamic software, and then the Synergy model is linked and complied to make field synergy calculations which are the further step handling of the original datas. And then, the calculation results will be shown in the CFD software, which is named by contours of Field Synergy Numbers.4) Based on the calculation results of field synergy models, the solid boundary of the flow field can be modified, and another calculation using CFD will be carried out to analyze the new fluid flow field. It is shown that the drag force of the flow drops when the average field synergy number increases, which coincides well with the prediction. By this procedure, the correctionand effectiveness of this Field Synergy model can be verified.5) In order to make connection of the Field Synergy model which is based upon thedynamic of particles with the total flow process of the fluid field, five evaluation indexes wereanalyzed and compared, and the vortex analysis is tried to be included in the suggestedevaluation index for Field Synergy model of fluid flow. It is shown that, Modulus Dot Productaverage should be adopted.6) Finally, the Field Synergy analysis model of fluid flow was used to analyze andoptimization on the flow process of steam ejector, especially the suction chamber in which theincompressible turbulent flow process occurs. After fluid dynamic analysis and experimentalstudying, its future application has been approved.