Flow Pattern and Heat Transfer in a Cylindrical Annulus Under 1 g and Low-g Conditions: Experiments

Columnar vortices induced by dielectrophoretic force in a stationary cylindrical annulus filled with a dielectric liquid

“…The present study aims to complement the linear stability analysis performed by Meyer et al (2017) and the DNS results (Kang & Mutabazi 2019) by providing more detailed information on velocity and temperature fields that can help to interpret the experimental results from the parabolic flight campaign (Dahley et al 2011;Meyer et al 2017Meyer et al , 2018Meyer et al , 2019Meier et al 2018). These experiments were performed with silicone oil AK5 for which Pr = 65 in an annular cylindrical cavity of inner radius R 1 = 0.5 cm with the radius ratio η = 0.5 and the axial aspect ratio Γ = 20.…”

“…2017, 2018, 2019; Meier et al. 2018). Besides the interest for microgravity environments, the existence of thermoelectric convection offers a new strategy of control of thermal convection in dielectric liquids and heat evacuation in systems using electric tension in plane or cylindrical heat exchangers, especially for microfluidic systems (Wadsworth & Mudawar 1990; McCluskey, Atten & Perez 1991; Barbic et al.…”

“…2017, 2018, 2019; Meier et al. 2018). These experiments used flow visualization techniques which provide only qualitative results on thermo-convective flows, and particle image velocimetry (PIV) measurements have furnished few quantitative data.…”

“…A high-frequency electric field imposed on a dielectric fluid with a temperature gradient produces a dielectrophoretic (DEP) force (Landau & Lifshitz 1984), which can generate thermoelectric convective flows (Roberts 1969;Turnbull 1969;Chandra & Smylie 1972;Yoshikawa, Crumeyrolle & Mutabazi 2013;Travnikov, Crumeyrolle & Mutabazi 2015Mutabazi et al 2016). The existence of thermoelectric convective flows induced by DEP force has been evidenced in experiments performed in the microgravity environment of Spacelab 3 aboard the space shuttle Challenger (Hart, Glatzmaier & Toomre 1986), in the GeoFlow experiments performed on the International Space Station (Futterer et al 2008(Futterer et al , 2013 and in parabolic flight experiments (Dahley et al 2011;Meyer et al 2017Meyer et al , 2018Meyer et al , 2019Meier et al 2018). Besides the interest for microgravity environments, the existence of thermoelectric convection offers a new strategy of control of thermal convection in dielectric liquids and heat evacuation in systems using electric tension in plane or cylindrical heat exchangers, especially for microfluidic systems (Wadsworth & Mudawar 1990;McCluskey, Atten & Perez 1991;Barbic et al 2001;Lin 2009).…”

“…The present study is an extension of this previous work and aims to characterize in more detail the hydrodynamic fields (velocity and vorticity, kinetic energy and enstrophy) and the temperature field for different values of the electric potential difference. The goal of this investigation is to get a better insight in recent results from experiments on thermoelectric convection performed during parabolic flight campaigns (Dahley et al 2011;Meyer et al 2017Meyer et al , 2018Meyer et al , 2019Meier et al 2018). These experiments used flow visualization techniques which provide only qualitative results on thermo-convective flows, and particle image velocimetry (PIV) measurements have furnished few quantitative data.…”