Newtonian liquid jet impaction on a high-speed moving surface

2015

JoVE

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds between 0 and 25 m/sec) and a spinning disk device (for examining surface speeds between 15 and 100 m/sec). The air cannon linear traverse is a pneumatic energy-powered system that is designed to accelerate a metal rail surface mounted on top of a wooden projectile. A pressurized cylinder fitted with a solenoid valve rapidly releases pressurized air into the barrel, forcing the projectile down the cannon barrel. The projectile travels beneath a spray nozzle, which impinges a liquid jet onto its metal upper surface, and the projectile then hits a stopping mechanism. A camera records the jet impingement, and a pressure transducer records the spray nozzle backpressure. The spinning disk setup consists of a steel disk that reaches speeds of 500 to 3,000 rpm via a variable frequency drive (VFD) motor. A spray system similar to that of the air cannon generates a liquid jet that impinges onto the spinning disc, and cameras placed at several optical access points record the jet impingement. Video recordings of jet impingement processes are recorded and examined to determine whether the outcome of impingement is splash, splatter, or deposition. The apparatuses are the first that involve the high speed impingement of low-Reynolds-number liquid jets on high speed moving surfaces. In addition to its rail industry applications, the described technique may be used for technical and industrial purposes such as steelmaking and may be relevant to high-speed 3D printing. Video LinkThe video component of this article can be found at

Section: Representative Resultscontrasting

confidence: 84%

Section: Representative Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Visualization of High Speed Liquid Jet Impaction on a Moving Surface

Guo

2015

JoVE

“…The latter case has been studied thoroughly in Lefebvre 27 and Keshavarz et al 24 Two dimensionless groups can express the singlephase Newtonian liquid discharge from a nozzle: Reynolds number and discharge coefficient, which is defined as Discharge Coefficient: The flow of these elastic solutions through a circular nozzle is significantly different from the flow of simple Newtonian liquids.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 8 shows two photos of elastic liquid jet impaction. The fact that Reynolds and Deborah numbers are the primary determinants of liquid splash motivated the authors to extend our simple model for Newtonian jet impact 24 to the case of elastic liquids. For equal values of shear viscosity, adding elasticity led to significant improvements of the splash threshold in all the tested cases.…”

Section: Resultsmentioning

confidence: 99%

Elastic liquid jet impaction on a high‐speed moving surface

Keshavarz

Eadie³

2012

AIChE Journal

Self Cite

In the railroad industry a friction‐modifying non‐Newtonian liquid, showing elastic behavior, may be applied to the rail in the form of a liquid jet. The interaction of this elastic liquid jet and the moving surface—specifically whether it splashes or adheres without splash—is important in this industrial application. Twelve different elastic liquids with widely varying relaxation times were tested to isolate the effect of elasticity from other fluid properties. Using high‐speed imaging, the interaction between the impinging jet and the moving surface could be captured and analyzed. Although similar to Newtonian jets, for which the Reynolds number plays a major role, the Deborah number was also salient to the splash of elastic liquids. At the elevated Weber numbers of the testing, the Weber number had a much smaller impact on splash than did the Reynolds or Deborah numbers. The ratio of the surface velocity to the jet velocity has only a small effect on the splash. © 2012 American Institute of Chemical Engineers AIChE J, 2012

Particle‐laden liquid jet impingement on a moving substrate

Rahmani

2017

AIChE Journal

The impingement of high speed jets on a moving surface was studied. The jet fluids were dilute suspensions of neutrally buoyant particles in water–glycerin solutions. At these low particle concentrations, the suspensions have Newtonian fluid viscosity. A variety of jet and surface velocities, solution properties, nozzle diameters, mean particle sizes, and volume fractions were studied. For each case the splash‐deposition threshold was quantified. It was observed that for jets with very small particles, addition of solids to the jet enhances deposition and postpones splash relative to a particle‐free water–glycerin solution with the same viscosity. In contrast, jets with larger particles in suspension were more prone to splash than single phase jets of the same viscosity. It is speculated that the change in character of the splash response for the jets with larger particles in suspension occurs when the particle diameter is comparable to the lamella thickness. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4673–4684, 2017