Experimental Study On The Dynamic Characteristics Of Film Coated Flow On Cylindrical Filament

The flow of the liquid film covering the wall of the cylindrical filament is a ubiquitous physical phenomenon in nature.The dynamic characteristics of the flow of the fibrous filament fluid film will have a huge impact on the quality of the coating process.During the coating process,the flow characteristics of the liquid on the fiber filaments are an important factor in determining the quality of the coating.By understanding the flow characteristics of the coating on the fiber filaments,the morphology and structure of the coating can be accurately controlled.Therefore,it is of great scientific significance and engineering application value to carry out research on the dynamic characteristics of film flow on cylindrical filaments and explore new methods for controlling interface stability and dynamic behavior.Aiming at the flow instability of high-viscosity fluids on cylindrical filaments,a series of experimental studies on the dynamic characteristics of membrane flow are carried out in this paper.Using the edge detection method based on bilateral filtering algorithm and Canny operator,the coordinate value of the edge of the liquid film in the experimental image is extracted,and then the characteristic parameters of the topography of the liquid film are obtained.According to these characteristic parameters,the flow characteristics,breaking mechanism and nonlinear evolution law of the viscous liquid film with free surface in the downflow are analyzed in depth,and the control of the stability and dynamic behavior of the coating interface on the cylindrical filament is explored.The results show that: there are three typical flow characteristics of high-viscosity liquid coating film flow on the filament.As the flow rate increases,the flow characteristics of liquids with different viscosities show a C-B-A conversion mode,and the critical flow rate for transition between C-B-A zones decreases with the increase in viscosity,achieving the interface stability and dynamics of the viscous liquid on the filament Precise regulation of behavior.The time-space evolution map obtained by the image processing method reveals the dynamic evolution law of the flow of high-viscosity liquid on the filament.This paper also designed a fluid film experimental device,and developed a non-contact experimental device for measuring the boundary morphology of the filament fluid film.The experimental device adopts a flexible split design and free combination of different parts to prepare fibrous filament fluid films with different film thicknesses and different flow rates.The fluid film prepared under different experimental conditions can be collected and recorded in real time through the image acquisition equipment.This paper uses the image processing module in MATLAB R2014 a to process the image,and develops the fluid film boundary coordinate extraction and fitting software and its GUI interface based on the Canny algorithm.