TJ485 : Experimental study of Newtonian and non-Newtonian droplet collision on inclined solid surface
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2017
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Abstarct: The collision of droplets on solid surfaces is widely used in oil and gas industry, surface painting, hot surface cooling and spraying of agricultural products. In the present study, non Newtonian drop fluid dispersion coefficient was studied experimentally on acrylic (Plexiglas) and stainless steel plate slopes, and compared with Newtonian droplets (water and glycerin and their solutions). In this study, non Newtonian and Newtonian fluid droplets collapsed at 27 and 47 cm from the solid solid surface in the range of Weber numbers 245≤We≤545.The effect of collision velocity and surface angles, viscosity and elasticity of fluid, water wettability and surface roughness have been investigated on the dispersion behavior and droplet accumulation. The results of this study show that with a decrease in viscosity and an increase in the collision rate, the rate and extent of dropping drops are higher. Non-native droplets of the bug have a higher and lower spread and diffusion rate, respectively, compared to Newtonian droplets of glycerin (with a higher viscosity) and water (with a lower viscosity), respectively. Also, the velocity of the collision and fluid viscosity have a great influence on the spreading stage, but the level of water wettability and surface roughness have little effect on drop dispersion. On the other hand, the effects of water-friendliness and surface roughness on the droplet accumulation stage are far more than that of the spreading stage. Also, with increasing collision velocity, the rate and amount of droplet accumulation increase and the amount of this increase depends on fluid viscosity. The rate and amount of droplet accumulation on the surface of the steel due to its high roughness is higher than that of the plexiglass. To investigate the elasticity of fluids, the droplets of Newtonian and non Newtonian fluids have been compared with each other with the same viscosity. In the same condition of mesosity, non-native droplets are less emitted due to their elastic properties compared to Newton's drop, but their accumulation rates are higher.
Keywords:
#Inclined surface #Non-Newtonian fluid of boger #Viscodity #Surface roughness #Velocity contact Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: