Electrical Discharge Group

Spanish

General Information

The Electrical Discharge Group is with the Universidad Tecnológica Nacional, Facultad Regional VenadoTuerto (FRVT). It was established in 2003 trough an agreement between the Institute of Plasma Physic at the University of Buenos Aires (Instituto de Físicadel Plasma, INFIP, CONICET-UBA) and the FRVT. The Group belongs to the Department of Electromechanical Engineering of the FRVT and its Laboratory is located in the campus of the FRVT in the VenadoTuerto City, Argentina.

The research area of the Group is Applied Plasma Physics. Plasma is an ionized gas consisting in a mixture of electrons, ions and neutral particles, but being electrically neutral. Plasma is thus an electrically conducting gas which has unique properties, and hence a large number of technological applications using (or assisted by) plasmas have been developed. Over 99% of the visible matter in the Universe (e.g., surface regions of the sun, interstellar gas clouds and the Earth’s magnetosphere) is in a state of plasma.

The usual way to generate plasmas at the Laboratory scale is by heating a gas trough an electrical discharge (“gas discharge”).The term gas discharge originated with the process of discharging an originally charged capacitor onto a gaseous gap between electrodes. If the voltage is sufficiently high, electric breakdown occurs in the neutral gas that passes to an ionized state. It is formed a closed circuit and the capacitor discharge produce a current through the gap that sustains the ionized state. Gas discharge physics covers a great variety of complex, multifaceted phenomena, and a large variety of experimental data and related theoretical models have been developed on this subject.

In particular, the Electrical Discharge Group at the Universidad Tecnológica Nacional performs research activities on two lines within the high-pressure (atmospheric or above) electrical discharges:

  1. High-current (~ 100 A) discharge devices which generate high-energy content and high-temperature plasmas; i.e., thermal plasmas,
  2. Low-current (≤ 0.1 A) discharge devices which generate highly non-equilibrium plasmas; i.e., non-thermal plasmas.
Non thermal plasma source
Thermal plasma source

Members

Researchers

Dr. Héctor J. Kelly

Head of the Group

Dra. Beatriz R. Mancinelli

Inv. UTN category C

Prof. Ord. UTN

Dr. Leandro Prevosto

Inv. Adjunto del CONICET

Inv. UTN category C

Prof. Ord. UTN

Ing. Jorge F. Amigo

Inv. UTN Cat. D

Prof. Ord. UTN

Ing. Natalio Milardovich

Prof. Ord. UTN

PhD Students

Ing. Juan Camilo Chamorro Garcés

Fellow of the CONICET

Under graduate Students

Sr. Ezequiel Cejas

Sr. Lucas Straccio

Research Areas

Thermal Plasmas-High-pressure arcs-Plasma Torches

Thermal plasmas are characterized by partial thermodynamic equilibrium (the electron temperature is close to the heavy particle temperature), high-energy content, high- temperatures, and high-luminosity. These special characteristics make attractive the use of thermal plasmas for material processing, and in fact they have been extensively used in many industrial applications since the early 1970’s. Some of these applications include thermal spraying, arc cutting, welding, re-melting and purification, smelting reduction, extractive metallurgy, ultrafine particle synthesis, powder spheroidization, waste treatment, circuit breakers and lighting.

Thermal plasma research currently in progress in our Group includes experimental and numerical characterization of transferred and non transferred dc arcs; development of cutting and spray-type torches, development of plasma diagnostics (sweeping electrostatic probes, refractive optical techniques, plasma light emission with temporal resolution and emission spectroscopy); modeling of plasma flow with atomic reactions, plasma sheaths structure and double arcing phenomena, and optimization and control for the processes of arc cutting of metal and concrete and related materials.

Non-thermal plasmas

A very active branch in plasma physics is the development of plasma sources able to provide energetic electrons, which produce in turn ions and highly active chemical reactive species, at relatively low gas temperatures. This is motivated by the large number of applications these sources have in plasma biology and plasma medicine, such as pathogen deactivation, wound disinfection, stopping of bleeding without damage of healthy tissue, acceleration of wound healing, control of bio-film proliferation, etc.

One of the most widespread sources of non-thermal plasmas is the corona discharge. A corona discharge appears as a luminous glow localizedin space around a point tip in a highly non-uniform electricfield. The physics of this source is well understood.The mechanism of multiplication of electrons is essentially dependent on the polarity of the electrode surrounded by the corona. If this electrode is the cathode (negative corona) then avalanche multiplication via secondary cathode emission takes place. The ignition of a negative corona does not differ from the Townsend breakdown. If the wire or tip is the anode (positive corona), the cathode does not participates in the electron multiplication process; the reproduction of electrons is ensured by secondary photo-processes in the gas around the tip.

Another device to generate non-thermal plasmas is the dielectric barrier discharge (DBD). DBDs use dielectric materials to cover one or both of two electrodes, and use high voltages in the kHz frequency range to ignite the discharge. Both planar and cylindrical electrode geometries have been used.In DBDs, charge collection on the dielectric layer that covers the electrodes causes a drop of the voltage across the plasma every time it is ignited and causes it to extinguish. Because of this DBDs are self-pulsed discharges that do not allow the discharge current increasing to a level that induces arcing. DBDs typically generate non-uniform plasmas that exhibit a large number of filaments/streamers appearing randomly between the electrodes.

Among different kind of sources, atmospheric pressure, low-current, low-temperature plasma jets are playing an increasing role also in various plasma processing applications, because they provide plasmas without spatial confinement. The basic geometrical scheme of a low-current plasma jet is similar to that employed in the generation of a high-current plasma torch: an electrical discharge is generated in an enclosed region while a relatively large gas flow is sent into the discharge, thus “blowing” the plasma to an outer region, usually unconfined space. Thus, a neutral plasma plume is formed containing ions, electrons, and excited reactive species dragged from the discharge region. The main difference between low-temperature jets and plasma torches is the average current circulating in the discharge, which rarely exceeds 0.1A in these “cold” jets.

Research Projects (in spanish)

Proyectos de investigación

Encurso

Universidad Tecnológica nacional

  1. PID UTN 2264 Tema: Descargas eléctricas de alta presión: estudio experimental y modelado numérico. 2014-2016. Dirección: Dr. Leandro Prevosto
  2. PID UTN 1389 Tema: Estudio experimental y simulación numérica de antorchas de plasma de arco no transferido para el corte térmico del concreto y materiales relacionados. 2011-2013 (extendido 2014). Dirección: Dr. Héctor Kelly.

Organismos externos

  1. CONICET PIP 11220120100453 Tema: Física y Aplicaciones de Plasmas a Presión Atmosférica. Dirección: Dr. Héctor Kelly. 2013-2015.

Concluidos

Universidad Tecnológica nacional

  1. PID UTN 25/Z012 Caracterización experimental y simulación numérica de antorchas de plasma para el corte de metales. 2008-2010. Dirección: Dr. Héctor Kelly.
  2. PID UTN Z 0007 Estudio experimental y caracterización de arcos de plasma de alta presión. 2005-2007. Dirección: Dr. Héctor Kelly.

Organismos externos

  1. CONICET PIP 11220090100219 Tema: Descargas eléctricas: Física básica y aplicaciones. Dirección: Dr. Héctor Kelly. 2010-2012.
  2. UBA, PID X 108 Tema "Desarrollo experimental, modelado numérico, caracterización y optimización de arcos de plasma" Dirección: Dr. Héctor Kelly 2008-2010.
  3. CONICET PIP 5378 Física Básica y Aplicaciones de Descargas Eléctricas. Dirección: Dr. Héctor Kelly. 2006-2008.
  4. UBA X 111 Desarrollo experimental, caracterización y optimización de arcos de plasma, 2004-2006. Dirección: Dr. Héctor Kelly.
  5. UBA X 106 Teoría de arcos de plasma, 2004-2006. Dirección: Dr. Fernando Minotti.
  6. CONICET PIP 02239 Estructura Plasma-Gas neutro generada en Arcos Eléctricos de baja Presión. Estudio experimental y Modelización (2002-2005).Dirección: Dr. Héctor Kelly.
  7. UBA X 214: La Estructura Plasma Gas Neutro Generada en Arcos Eléctricos de Baja Presión: Estudio Experimental y Modelización Numérica. Agosto 2002 a marzo 2004. Dirección: Héctor Kelly.

Publications in books or books chapters

  1. Numerical Modelling of a Cutting Arc Torch, B. Mancinelli, F. O. Minotti, L. Prevosto and H. Kelly. Computational and Numerical Simulations, Chapter 4 pp 65-82, J. Awrejcewicz Ed. (InTech Open Access Publisher, 2014). ISBN 978-953-51-1220-4. Available from: http://dx.doi.org/10.5772/57045. (Por invitación).
  2. On the double-arcing phenomenon in cutting arc torch, L. Prevosto, H. Kelly and B. Mancinelli. Numerical Simulations of Physical and Engineering Processes, Chapter 23 pp 503-524, J. Awrejcewicz Ed. (InTech Open Access Publisher, 2011). ISBN 978-953-307-620-1. Available from: http://dx.doi.org/10.5772/23739 (Por invitación).

Publications in indexedjournals

  1. Numerical investigation of the double-arcing phenomenon in a cutting arc torch, B. Mancinelli, F. O. Minotti, L. Prevosto and H. Kelly, Journal of Applied Physics 116 023301 (7 pp), 2014. ISSN: 0021-8979. (Archivo: 2014_a.pdf)
  2. On the use of the double floating probe method to infer the difference between the electron and the heavy particles temperatures in an atmospheric pressure, vortex–stabilized nitrogen plasma jet, L. Prevosto, H. Kelly and B. Mancinelli. Rev. Sci. Instruments 85 053507 (6 pp), 2014. ISSN: 0034-6748. (Archivo: 2014_b.pdf)
  3. Langmuir probe measurements in a time-fluctuating-highly ionized non-equilibrium cutting arc: Analysis of the electron retarding part of the time-averaged current-voltage characteristic of the probe, L. Prevosto, H. Kelly and B. Mancinelli. Rev. Sci. Instruments 84 123506 (7 pp), 2013. ISSN: 0034-6748. (Archivo: 2013.pdf)
  4. Langmuir probe diagnostics of an atmospheric pressure, vortex–stabilized nitrogen plasma jet, L. Prevosto, H. Kelly and B. Mancinelli. Journal of Applied Physics112 063302 (7pp), 2012. ISSN: 0021-8979. (Archivo: 2012_b.pdf)
  5. On the dynamics of cutting arc plasmas: the role of the power supply ripple, L. Prevosto, B. Mancinelli and H. Kelly. Advanced Electromagnetics vol. 1, no. 2 (4pp), 2012. ISSN 2119-0275. (Archivo: 2012_a.pdf)
  6. On the dynamics of the space-charge layer inside the nozzle of a cutting torch and its relation with the "non-destructive" double-arcing phenomenon, L. Prevosto, H. Kelly and B. Mancinelli. Journal of Applied Physics 110 083302 (5pp), 2011. ISSN: 0021-8979. Citado en Physics Update de Physics Today vol. 64 (2011) “A double take on the double arc” (page 24) ISSN: 0031-9228. (Archivo: 2011_b.pdf)
  7. Departures from local thermodynamic equilibrium in cutting arc plasmas derived from electron and gas density measurements using a two-wavelength quantitative schlieren technique, L. Prevosto, G. Artana, H. Kelly and B. Mancinelli. Journal of Applied Physics 109 063302 (6pp), 2011. ISSN: 0021-8979. (Archivo: 2011_a.pdf)
  8. Schlieren technique applied to the arc temperature measurement in a high energy density cutting torch, L. Prevosto, G. Artana, B. Mancinelli and H. Kelly. Journal of Applied Physics 107 023304 (5pp), 2010. ISSN: 0021-8979. (Archivo: 2010_a.pdf)
  9. Determination of plasma velocity from light fluctuations in a cutting torch, L. Prevosto, H. Kelly and B. Mancinelli. Journal of Applied Physics 106 053308 (4pp), 2009. ISSN: 0021-8979. (Archivo: 2009_d.pdf)
  10. On the space-charge boundary layer inside the nozzle of a cutting torch, L. Prevosto, H. Kelly and B. Mancinelli. Journal of Applied Physics105 123303 (5 pp.), 2009. ISSN: 0021-8979. (Archivo: 2009_c.pdf)
  11. An Interpretation of Langmuir Probe Floating Voltage Signals in a Cutting Arc, L. Prevosto, H. Kelly and B. Mancinelli. IEEE Trans. Plasma Science, vol. 37 no. 6, pp. 1092-1098, 2009. ISSN: 0093-3813. (Archivo: 2009_b.pdf)
  12. On the physical origin of the nozzle characteristic and its connection with the double-arcing phenomenon in a cutting torch, L. Prevosto, H. Kelly and B. Mancinelli. Journal of Applied Physics 105 013309 (6 pp.), 2009. ISSN: 0021-8979. (Archivo: 2009_a.pdf)
  13. On the use of the metallic nozzle of a cutting torch as a Langmuir probe, L. Prevosto, B. Mancinelli and H. Kelly. Phys. Scr.T131 014026 (4 pp.), 2008. ISSN: 0031-8949. (Archivo: 2008_c.pdf)
  14. On the Use of Sweeping Langmuir Probes in Cutting Arc Plasmas – Part I: Experimental Results, L. Prevosto, H. Kelly and B. Mancinelli. IEEE Trans. Plasma Science, vol. 36 no. 1, pp. 263-270, 2008. ISSN: 0093-3813. (Archivo: 2008_b.pdf)
  15. On the Use of Sweeping Langmuir Probes in Cutting Arc Plasmas – Part II: Interpretation of the Results, L. Prevosto, H. Kelly and F. O. Minotti. IEEE Trans. Plasma Science vol. 36 no. 1, pp. 271-277, 2008. ISSN: 0093-3813. (Archivo: 2008_a.pdf)
  16. Hydrodynamic Model for the Plasma-Gas Flow in a Cutting Torch Nozzle. H. Kelly, F. O. Minotti, L. Prevosto, B. Mancinelli, Brazilian Journal of Physics, vol. 34, no. 4B, pp. 1531-37, December, 2004. ISSN 0103-9733. (Archivo: 2004_b.pdf)
  17. Experimental Characterisation of a Low-Current Cutting Torch. H. Kelly, B. Mancinelli, L. Prevosto, F. O. Minotti, A. Márquez. Brazilian Journal of Physics, vol. 34, no. 4B, pp. 1518-22, December, 2004. ISSN 0103-9733. (Archivo: 2004_a.pdf)

Publications in meeting proceedings

  1. Diagnostics in cutting arc plasmas, L. Prevosto and H. Kelly, Journal of Physics: Conference Series 511, 012065 (6 pp.), 2014. ISSN 1742-6588.
  2. Numerical Modeling of a Cutting Torch, B. Mancinelli. F. O. Minotti and H. Kelly, Journal of Physics: Conference Series 511, 012071 (6 pp.), 2014. ISSN 1742-6588.
  3. Modelado numérico 2-D de la ruptura dieléctrica del gas en la lámina no-neutra contigua a la tobera de una antorcha de arco transferido, B. R. Mancinelli, F. O. Minotti y L. Prevosto. Anales AFA volumen especial Fluidos 2012, vol. 23, nro. 3, 53-57, 2013. ISSN: 1850-1158.
  4. On the Dynamic Behavior of the Anode–Arc–Root at the Nozzle Surface in a Non-transferred Plasma Torch, L. Prevosto, M. Risso, D. Infante, E. Cejas, H. Kelly and B. Mancinelli, Journal of Physics: Conference Series 370, 012048 (4pp), 2012. ISSN 1742-6588.
  5. Numerical Modeling of the Gas Breakdown Development in the Space–Charge Layer inside the Nozzle of a Transferred Arc Torch, B. Mancinelli, L. Prevosto and F. O. Minotti, Journal of Physics: Conference Series 370, 012035 (5pp), 2012. ISSN 1742-6588.
  6. Correlation methods in cutting arcs, L. Prevosto and H. Kelly Journal of Physics: Conference Series 296 012005 (6pp), 2011. ISSN 1742-6588.
  7. On the use of the Prandtl mixing length model in the cutting-torch modeling, B. Mancinelli, F. O. Minotti and H. Kelly. Journal of Physics: Conference Series 296 012025 (6pp), 2011. ISSN 1742-6588.
  8. Numerical modelling of a cutting torch, B. Mancinelli, F. O. Minotti and H. Kelly. Journal of Physics: Conference Series (2010, accepted).
  9. Diagnostics in cutting arc plasmas, L. Prevosto and H. Kelly, Journal of Physics: Conference Series (2010, accepted).
  10. On the influence of the nozzle length on the arc properties in a cutting torch, L. Prevosto, H. Kelly, M. Risso and D. Infante. Journal of Physics: Conference Series 166 (2009) 012021. ISSN 1742-6588.
  11. Interpretation of Voltage Measurements in Cutting Torches, L. Prevosto, H. Kelly, B. Mancinelli, F. O. Minotti. AIP Conference Proceedings 2006 Volume 875. ISBN 978-0-7354-0375-8. Editor Julio Herrera Velázquez. 207-210.

PhD Tesis

  1. Leandro Prevosto. Title: Phisical properties and applications of low-current cutting torches. Director: Dr. Héctor Kelly. Facultad Ingeniería de la Universidad de Buenos Aires. 2009. (Archivo: Tesis_LP.zip)
  2. Beatriz Mancinelli. Title: Theoretical modelling and numerical simulation of transferred arc torches. Director: Dr. Fernando O. Minotti. Universidad Tecnológica Nacional Facultad Regional Córdoba. 2010. (Archivo: Tesis_BM.zip)

International Meetings

  1. Advanced Electromagnetic Symposium 2012 (AES 2012), Paris, Francia. Abril de 2012. Trabajo presentado: “On the dynamics of the cutting arc plasmas: the role of the power supply ripple”, L. Prevosto, B. Mancinelli and H. Kelly.
  2. XIV Latin-American Workshop on Plasma Physics (LAWPP), Mar del Plata, Argentina. Noviembre de 2011. Trabajo presentado: “On the Dynamic Behavior of the Anode–Arc–Root at the Nozzle Surface of a Non-transferred Plasma Torch”, L. Prevosto, M. Risso, D. Infante, E. Cejas, H. Kelly and B. Mancinelli.
  3. XIV Latin-American Workshop on Plasma Physics (LAWPP), Mar del Plata, Argentina. Noviembre de 2011. Trabajo presentado: “Numerical Modeling of the Gas Breakdown Development in the Space–Charge Layer inside the Nozzle of a Transferred Arc Torch”, B. Mancinelli, L. Prevosto, and F. O. Minotti.
  4. ICPP and XIII Latin American Workshop on Plasma Physics, Santiago de Chile, Agosto 2010. Trabajo presentado: Numerical modelling of a cutting torch, B. Mancinelli, F.O. Minotti and H. Kelly.
  5. On the use of the metallic nozzle of a cutting arc torch as a Langmuir probe, L. Prevosto, B. Mancinelli, H. Kelly. XII LAWPP, Caracas Venezuela, Septiembre de 2007.
  6. Interpretation of Voltage Measurements in Cutting Torches, L.Prevosto, H.Kelly, B. Mancinelli, and F.O. Minotti presentado en el XI Latin American Workshop on Plasma Physics , 5-9 de Diciembre de 2005 en México.
  7. Experimental characterization of a low-current cutting torch, H.Kelly, B. Mancinelli, L. Prevosto, F.O. Minotti, and A. Márquez; presentado en el X Latin American Workshop on Plasma Physics Combined with 7th Brazilian Meeting on Plasma Physics, 30 de noviembre al 5 de diciembre de 2003, en Sao Pedro, Brasil.
  8. Hydrodynamic Model for the Plasma-Gas Flow in a Cutting Torch Nozzle, H.Kelly, F.O. Minotti, L. Prevosto, B. Mancinelli; presentado en el X Latin American Workshop on Plasma Physics Combined with 7th Brazilian Meeting on Plasma Physics, 30 de noviembre al 5 de diciembre de 2003, en Sao Pedro, Brasil.

Regional Meetings

  1. XII Reunión de fluidos y sus aplicaciones (FLUIDOS 2012), Buenos Aires, Argentina. Noviembre de 2012. Trabajo presentado: “Two-dimensional numerical modeling of the gas breakdown in the space-charge layer inside the nozzle of a transferred arc torch”, B. Mancinelli, F. O. Minotti and L. Prevosto.
  2. XII Reunión de fluidos y sus aplicaciones (FLUIDOS 2012), Buenos Aires, Argentina. Noviembre de 2012. Trabajo presentado: “Study of a thermal plasma jet by means of a Langmuir probe”, L. Prevosto, H. Kelly and B. Mancinelli.
  3. XI Reunión sobre recientes avances en física de fluidos y sus aplicaciones, Colonia del Sacramento (Uruguay) 3-5 noviembre de 2010. Trabajo presentado: “Generalized temperature correlation in cutting arcs”, Prevosto L. and Kelly H.
  4. 94 Reunión anual de la Asociación de Física Argentina (AFA), Rosario 14-18 de septiembre de 2009. Trabajo presentado “Simulación numérica de una antorcha de 30 A”, Mancinelli B., Minotti F. O. y Kelly H.
  5. 94 Reunión anual de la Asociación de Física Argentina (AFA), Rosario 14-18 de septiembre de 2009. Trabajo presentado: “Velocimetry techniques in highly constricted plasma jets”, Prevosto L., Kelly H., Mancinelli B, Infante D. y Risso M.
  6. X Reunión sobre recientes avances en física de fluidos y sus aplicaciones, Santa Fe 19-21 noviembre de 2008. Sobre el origen físico del perfil radial de las señales flotantes en arcos de plasma de alta presión. Prevosto L., Kelly H., Mancinelli B.
  7. X Reunión sobre recientes avances en física de fluidos y sus aplicaciones, Santa Fe 19-21 noviembre de 2008. Modelado numérico de una antorcha de arco transferido, Mancinelli B., Minotti F. y Kelly H.
  8. IX Reunión sobre recientes avances en física de fluidos y sus aplicaciones, Mendoza 1-3 noviembre de 2006. Estudio experimental de un jet supersónico de plasma térmico mediante la utilización de sondas de Langmuir, Prevosto L., Kelly H., Mancinelli B.
  9. IX Reunión sobre recientes avances en física de fluidos y sus aplicaciones, Mendoza 1-3 noviembre de 2006. Teoría de sondas en arcos de plasma de alta presión, Mancinelli B., Prevosto L., Kelly H., Minotti F.
  10. AFA 2004, Bahía Blanca, setiembre de 2004. Mediciones Interferométricas de Densidad en un Arco Transferido, Bilbao L., Kelly H., Mancinelli B., Prevosto L.