کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
655423 | 1457649 | 2011 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Newtonian liquid jet impaction on a high-speed moving surface Newtonian liquid jet impaction on a high-speed moving surface](/preview/png/655423.png)
In the railroad industry a friction modifying agent may be applied to the rail or wheel in the form of a liquid jet. In this mode of application the interaction between the high-speed liquid jet and a fast moving surface is important. Seven different Newtonian liquids with widely varying shear viscosities were tested to isolate the effect of viscosity from other fluid properties. Tests were also done on five surfaces of different roughness heights to investigate the effects of surface roughness. High-speed video imaging was employed to scrutinize the interaction between the impacting jet and the moving surface. For all surfaces, decreasing the Reynolds number reduced the incidence of splash and consequently enhanced the transfer efficiency. At the elevated Weber numbers of the testing, the Weber number had a much smaller impact on splash than the Reynolds number. The ratio of the surface velocity to the jet velocity has only a small effect on the splash, whereas increasing the roughness-height-to-jet-diameter ratio substantially decreased the splash threshold.
► We studied experimentally the interaction of a liquid jet with a moving surface.
► Decreasing the Reynolds number reduced the incidence of splash.
► The Weber number had a much smaller impact on splash than the Reynolds number.
► The jet impingement angle had only a small effect on the splash.
► Increasing the surface roughness substantially decreased the splash threshold.
Journal: International Journal of Heat and Fluid Flow - Volume 32, Issue 6, December 2011, Pages 1216–1225