Electric-discharge effect in a plasma wake flow: Pulsation energy redistribution toward lower frequencies

Mode intermittence in a wake from two cylinders

“…Experimental velocity spectra for the wake at non-self-sustained glow discharge and relevant spectra for the neutral gas flow (that is a reference data) were compared. When the distance between cylinder axes was about of / 2.2 L D  , the velocity spectrum with one peak was observed in the case of gas wake, as is seen from figure 2a [5].…”

“…We try to adopt the technique of flow control by the electrical discharge in the fast-flow CO2-laser where the glow discharge exists ab initio. A promising result has been achieved for the plasma flow of near wake from two parallel cylinders as is in figure 1 [5]. In that study the wake from cylinders in the case of side-byside arrangement was studied for the mixture composed of nitrogen and helium (at pressure of tens mbar).…”

An Approach to Plasma Wake Studying

“…Assuming quasi-stationary state of the wake behind the formation zone, the model transforms to a one-dimensional type through the transformation wake translation t t x u → − as it is done for Landau model [22]. Moreover, direct experimental evaluation of nonlinearity parameter ε , by treating velocity oscillograms of transient wake regimes, led to value [25] 2~0.3 ε ε = for our case [20] [25] and new notation of set (1,2). As parameter ε is small the Poincare-Krylov-Bogolyubov method of slow amplitudes and phases [26] has been applied for solving the set (1, 2) by using the form:…”

“…We used such approach for turbulent wake modeling with van-der-Pole equation as the starting point, accordingly, no immediate limitation on Reynolds number arises for this option. In experiment [20] in the chamber of fast-flow CO 2 -laser the cylinders of low aspect ratio were used: ~3.5 H D . This circumstance allows us neglect the wake dynamics in direction of cylinders axes, according to results [24].…”

“…We tried to adopt the technique of flow control by the electrical discharge in the fast-flow CO 2 -laser where the glow discharge exists ab initio. A promising result has been achieved for this case [20]. In that study the wake from two parallel circular cylinders in the side-by-side arrangement was studied for the mixture composed of 16 Torr nitrogen and 2 Torr helium, see Figure 1.…”