Velocity and Turbulence Intensity of an EHD Impinging Dielectric Liquid Jet in Blade–Plane Geometry

Abstract

An impinging jet in a dielectric liquid is generated by applying a high potential difference to a blade-plane geometry. This kind of jet is both a fluid flow and an electrical phenomenon. In our study, an overview of the flow field is easily obtained by using the classical particle velocity method. Two patterns of electrohydrodynamic velocity profiles of the jet can be observed when the applied high voltage varies. A typical method for a classical impinging jet is used in order to point out the specific characteristics of electrohydrodynamic jets. Electric current measurements and particle-image-velocimetry investigations are conducted synchronously, which contribute to the analysis of this electrohydrodynamic phenomenon. Two electrical current regimes are presented according to the potential difference.Index Terms-Blade-plane geometry, dielectric liquids, electric potential, electrohydrodynamics, fluid flow control, particle image velocimetry (PIV). NOMENCLATUREThree velocity components in Cartesian coordinates and their vector norms. For a 2-D flow in xy plane, V = V 2 x + V 2 y . V c Mean streamwise distribution of centerline velocity. V c,max Maximum value of V c .

Moffatt eddies in electrohydrodynamics flows: numerical simulations and analyses

“…As we can see, its value also increases with increasing T ∈ [500, 2900]. The typical characteristics of the EHD flow structure discussed above are consistent with those obtained from previous numerical simulations (Park et al 2004;Wu et al 2013) and experiments in the injection regime (Yan et al 2013;Daaboul et al 2017;Sun et al 2020). Figure 6(b) depicts |U| s max , (where the superscript 's' represents the saturated |U| max of the final steady state; see figure 6a) as a function of T from 500 to 10 000.…”

Numerical Investigation of Electrohydrodynamic Plumes for Locally Enhanced Cooling in Dielectric Liquids

“…6 shows the isocontours of the horizontal and longitudinal velocities at the final steady state corresponding to Fig. 4, which were in qualitative agreement with recent experimental observations [8], [55], [56], [57].…”

“…Three different flow regimes (stable, regularly periodic, and chaotic) were observed by increasing the driving electric Rayleigh number. All three regimes have been confirmed by later experimental observations [8]. In [30], an attempt has been made to compare numerical solutions and experimental results of the blade-plate configuration.…”

“…It is interesting to point out that EHD plumes share some analogies with thermal plumes due to a heat source [5], [6] and impinging jets [7], [8].…”

Experimental studies of influence of different electrodes on bridging in contaminated transformer oil

“…The motion of the particles was consistent with electro-convective flow due to charge injection into a dielectric liquid [24]. In this case the high electric field creates two turbulence waves propagating from the needle to the plane and returning back at the sides [25]. In dielectric liquids, space charges (ions) are mainly created by two mechanisms: one is the dissociation and recombination phenomenon [26], the other one is the charge injection [27].…”