Hypergravity influence on gliding arc in noble gases

The effects of increased artificial gravity (in the range 1g-18g) on gliding arcs in four noble gases (He, Ne, Ar, Kr) were the subject of this experimental study

Gravity effects on a gliding arc in four noble gases: from normal to hypergravity

A gliding arc in four noble gases (He, Ne, Ar, Kr) has been studied under previously unexplored conditions of varying artifiial gravity, from normal 1 g gravity up to 18 g hypergravity. Signifiant differences, mainly the visual thickness of the plasma channel, its maximum elongation and general sensitivity to hypergravity conditions, were observed between the discharges in individual gases, resulting from their different atomic weights and related quantities, such as heat conductivity or ionisation potential. Generally, an increase of the artifiial gravity level leads to a faster plasma channel movement thanks to stronger buoyant force and a decrease of maximum height reached by the channel due to more intense losses of heat and reactive species. In relation to this, an increase in current and a decrease in absorbed power was observed

Tetrakis(trimethylsilyloxy)silane for nanostructured SiO2-like films deposited by PECVD at atmospheric pressure

We performed the thin films deposition using atmospheric pressure plasma enhanced chemical vapour deposition (AP-PECVD) by means of a radiofrequency and a microwave plasma jets operating with mixtures of argon and tetrakis(trimethylsilyloxy)silane (TTMS)

Hypergravity effects on glide arc plasma

The behaviour of a special type of electric discharge – the gliding arc plasma – has been investigated in hypergravity (1g –18g) using the Large Diameter Centrifuge (LDC) at ESA/ESTEC. The discharge voltage and current together with the videosignal from a fast camera have been recorded during the experiment. The gliding of the arc is governed by hot gas buoyancy and by consequence, gravity. Increasing the centrifugal acceleration makes the glide arc movement substantially faster. Whereas at 1g the discharge was stationary, at 6g it glided with 7 Hz frequency and at 18g the gliding frequency was 11 Hz. We describe a simple model for the glide arc movement assuming low gas flow velocities, which is compared to our experimental results

Characteristics of the pipe junction with 2.4 cross-section area ratio for the case of the flow division

There are presented characteristics of the pipe junction for the case of the flow division in this paper. The pipe junction consists of one straight pipe, with the diameter 50 mm and one adjacent pipe with diameter 32 mm. The characteristics have been measured for five different angles of the adjacent pipe

Gliding arc subjected to hypergravity

We studied the influence of hypergravity on gliding arc plasma in noble gases. The hypergravity affected the plasma channel propagation

Experimental study of gliding arc plasma channel motion: buoyancy and gas flow phenomena under normal and hypergravity conditions

The details of plasma channel motion are investigated by frame-by-frame image analysis of high speed recording of a gliding arc. The gliding arc is operated in several noble gases at various flow rates, voltages and artificial gravity levels. Several peculiarities in evolution of individual glides are observed, described and discussed, such as accelerating motion of plasma channel or shortcutting events of various kinds. Statistics of averaged parameters are significantly different for buoyancy and gas drag dominated regimes, which is put into relation with differing flow patterns for hypergravity and high gas flow