Spin coating and air-jet blowing of thin viscous drops

Experimental results are reported on the assessment of steady and pulsed air jet vortex generators (AJVGs) for the suppression of dynamic stall on a sinusoidal pitching RAE9645 airfoil model. Tests at Rec of 1 million, at reduced pitching frequencies between 0.01 and 0.10 were performed with and without steady and pulsed AJVG blowing. The effect of jet momentum coefficient (0.0003< Cμ< 0.0046), jet duty cycle (0.25< DC< 1) and jet pulsing frequency (0.29< F+< 2.93) were investigated. Pulsed air jet blowing with F+ in the range 0.5–1.0 and with a duty cycle in the range 0.4–0.5, was found to be the most effective to achieve full suppression of dynamic stall vortex formation.

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Improvement of wind turbine aerodynamic performance by vanquishing stall with active multi air jet blowing

Energy ◽

10.1016/j.energy.2021.120176 ◽

2021 ◽

pp. 120176

Author(s):

Morteza Mohammadi ◽

Mohammad Javad Maghrebi

Keyword(s):

Wind Turbine ◽

Aerodynamic Performance ◽

Air Jet ◽

Jet Blowing

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Visualization of Entrainment and Surface Behavior of High Speed Air Jet Blowing Out From a Hole to Stagnant Water

Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles ◽

10.1115/icone20-power2012-55068 ◽

2012 ◽

Author(s):

Kohei Nago ◽

Yasuo Koizumi ◽

Akihiro Uchibori ◽

Hiroyuki Ohshima

Keyword(s):

High Speed ◽

Two Phase Flow ◽

Droplet Diameter ◽

Video Camera ◽

Diameter Distribution ◽

Phase Flow ◽

Stagnant Water ◽

Two Phase ◽

Air Jet ◽

Jet Blowing

A two dimensional air jet was blown out from a nozzle into water in a thin vessel. The behavior of the interface between water and the air jet and also the air jet were recorded with a high speed video camera. Filament-like ears and wisps pulled-out from the wavy water surface were noticed in the recorded photos. Droplets are formed from these. Droplet diameters were obtained from the recorded photos. As the air velocity increased, the number of droplets created by the air jet increased lineally and the smaller droplets increased. The correlation for the droplet diameter distribution developed for the annular dispersed two-phase flow in a pipe predicted well the present results. The correlations for the droplet diameter developed for the annular dispersed two-phase flow in a pipe and for the jet blowing out from the stagnant water pool considerably underpredict the experimental results.

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