TY - JOUR
T1 - Preparation of Free-Surface Hyperbolic Water Vortices
AU - Klymenko, Roman
AU - Nanninga, Harmen
AU - de Kroon, Esther
AU - Agostinho, Luewton L.F.
AU - Fuchs, Elmar C.
AU - Woisetschläger, Jakob
AU - Hoeben, Wilfred F.L.M.
N1 - Publisher Copyright:
© 2023, Journal of Visualized Experiments. All rights reserved.
PY - 2023/7
Y1 - 2023/7
N2 - Free surface vortices are present in industry in flow regulation, energy dissipation, and energy generation. Although investigated extensively, detailed experimental data regarding free surface vortices are lacking, particularly regarding the turbulence at the interface. The present paper reports on a special type of free surface vortex first proposed by Walter Schauberger in the 1960s that has an oxygen volumetric mass transfer coefficient exceeding the value of similar systems. This special type of vortex forms in a hyperbolic funnel. Different stable regimes can be stabilized with different hydraulic characteristics. Other advantages of this technology are its energy efficiency, simple design, and scalability. The flow in this hyperbolic funnel is characterized by strong turbulence and an increased surface area of the air-water interface. The local pressure strongly varies along the surface, resulting in a pronounced wavey air-water boundary layer. Due to the helical flow, these perturbations move inward, pulling the boundary layer with them. The resultant pressure gradient draws a certain air volume into the water vortex. The construction of the basic hyperbolic funnel setup and operational examples, including high-speed visualization for three different stable regimes, are presented in this work.
AB - Free surface vortices are present in industry in flow regulation, energy dissipation, and energy generation. Although investigated extensively, detailed experimental data regarding free surface vortices are lacking, particularly regarding the turbulence at the interface. The present paper reports on a special type of free surface vortex first proposed by Walter Schauberger in the 1960s that has an oxygen volumetric mass transfer coefficient exceeding the value of similar systems. This special type of vortex forms in a hyperbolic funnel. Different stable regimes can be stabilized with different hydraulic characteristics. Other advantages of this technology are its energy efficiency, simple design, and scalability. The flow in this hyperbolic funnel is characterized by strong turbulence and an increased surface area of the air-water interface. The local pressure strongly varies along the surface, resulting in a pronounced wavey air-water boundary layer. Due to the helical flow, these perturbations move inward, pulling the boundary layer with them. The resultant pressure gradient draws a certain air volume into the water vortex. The construction of the basic hyperbolic funnel setup and operational examples, including high-speed visualization for three different stable regimes, are presented in this work.
UR - http://www.scopus.com/inward/record.url?scp=85166580556&partnerID=8YFLogxK
U2 - 10.3791/64516
DO - 10.3791/64516
M3 - Article
AN - SCOPUS:85166580556
SN - 1940-087X
VL - 2023
JO - Journal of visualized experiments
JF - Journal of visualized experiments
IS - 197
M1 - e64516
ER -