Ionic windIonic wind refers to the air motion produced by drifting charges, accelerated by an electric field whilst colliding with neutral air molecules. These collisions transfer part of the ions momentum into the air in the direction of the applied electric field, so that a macroscopic wind is created, the so-called ‘ionic-wind’. This wind is related to Electro-Hydro-Dynamic (EHD) propulsion since it produces air motion from the action of an electric field into the air. Since specific effects associated with charge creation arising in gases only are needed for ionic wind to arise, the less common acronym Electro-Aero-dynamic (EAD) is also used in the community.
Ionic wind is of interest in distinct applications such as electrostatic precipitators, gas and ionic pumps, miniaturized heat-cooler, xerography (i.e. electro-photography) and propulsion. In gases, charge creation are generally associated with the existence of a corona discharge, which is a cold plasma near a high electric field.
propulsion is an emerging field of investigation in the context of air-plane electrification and low-carbon air transportation. Recent advances in the field by Pr. Barrett team at MIT have demonstrated the (short) autonomous flight of a 3m span drone, partly motivated by our previous prediction that gliders such as Solar Impulse II could be propelled, in stationary flight, by ionic wind. In this emerging field, active investigations are in progress in various directions, including trying to improve ion-sources reliability and operability, (e.g. for drone propulsion applications).
What can we learn about the propulsive capabilities of ionic wind and the underlying physics by conjugating experimental investigations, numerical modeling, and theoretical analysis?
During the last years we experimentally confirmed (as other groups) the original findings of Pr. Barrett group that ionic wind provides a much larger thrust-to-power ratio than classical thermal engines, allowing the stationary flight of gliders such as Solar Impulse II (see Monrolin et al, 2017). We also confirmed the existence of optimal source configurations (
emitters/collectorsThese high electric fields are generated by high voltage sources called emitters in the vicinity of which charges are created. Among those charges, unipolar charges are migrating from the emitter vicinity, out of the narrow corona-discharge region, into air, toward the electrode of opposed polarity, which is called a collector since it collects the charges.
) for ionic wind propulsion and we understood, from Particle Image Velocity (PIV) experimental analysis, that this optimality is associated with a trade-off between maximizing the electric field and lowering the drag force (see Monrolin, 2018). We also recently demonstrated that the observed thrust can be predicted by numerical simulations in many configurations (see Coseru et al, 2021). From a more fundamental viewpoint we also progressed on the understanding of the corona discharge physics which, being the origin of charges, is a central issue to ionic wind propulsion. First considering the simplest case of axi-symmetric electrode configurations, we performed a theoretical analysis which permits to (asymptotically) demonstrate Kaptzov hypothesis and Peek’s law, two well-known features of corona discharge (see Monrolin et al, 2018). We recently generalised this theoretical multi-scale asymptotic approach for general configurations so as to set up a rigorous framework for already used multi-domain formulation of corona discharge modeling (see Monrolin et al, 2019).
In the future we will focus on ionic wind propulsive capability in the presence of adverse flow, i.e. referring to airplane cruise velocity conditions. This question is challenging from experimental and theoretical/numeral aspects.
Flying with ionic windAn aeroplane can sustain steady-level flight using ionic wind.See Plouraboué, 2018Electrohydrodynamic thrust for in atmosphere propulsionExperimental thrust measurement.See Monrolin et al, 2017Electrohydrodynamic ionic wind, force field, and ionic mobilityKinetic to electric power ratio versus collector spacing angleSee Monrolin, 2018Ion density, isopotential lines and electric field for 2 Emitters/2 Collectors configuration
Numerical study of Electro Aero dynamic force and current resulting from ionic wind in emitter/collector systems
Coseru et al, 2021Revisiting the positive DC corona discharge theory beyond Peek and Townsend lawCoaxial electrode geometry, asymptotic regions and the corresponding physical processes: (1) Primary electron avalanche, (2) secondary ionization,
(3) secondary electron avalanche, (4) ion drift.See Monrolin et al, 2018
Previous
Next
Publications
2022
Julien, Lemetayer; Corentin, Marion; David, Fabre; Franck, Plouraboué
Multi-inception patterns of emitter array/collector systems in DC corona discharge Journal Article
In: Journal of Physics D: Applied Physics, 55 , 2022.
@article{Lemetayer_2022,
title = {Multi-inception patterns of emitter array/collector systems in DC corona discharge},
author = {Lemetayer Julien and Marion Corentin and Fabre David and Plouraboué Franck},
url = {https://iopscience.iop.org/article/10.1088/1361-6463/ac4e35},
doi = {10.1088/1361-6463/ac4e35},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Journal of Physics D: Applied Physics},
volume = {55},
abstract = {Multiple emitters systems have been previously used so as to increase charge density in the drift region, many times without producing sensible increment neither in total current nor ionic wind. This contribution focuses on analyzing the detailed physics behind this failure, that is named 'multiple emitters un-scalability'. It is established that multiple emitters un-scalability is related to the inability of multiple corona discharge inceptions when increasing the emitter number and/or density. This confirms recent findings that corona discharge inception is shielded by electro-static interactions between emitters. This contribution demonstrates that this shielding can be balanced by emitter/collector electrostatic interactions depending on the considered configuration. For sufficiently close collector-emitter distances, ignition starts at the array center, whereas, on the contrary, when the collector is distant, the ignition not only starts at the array's periphery but might also be limited there. It is also demonstrated that emitter/emitter electrostatic interactions can be balanced by emitter/collector ones, depending of their chosen configuration. This lead to a variety of multi-inception patterns, the condition of which are analyzed. Intermediate configurations for which the collector is neither sufficiently close nor distant from the emitter array center provide a variety of multi-inception patterns that are hereby analyzed. Combining finite element computations of multi-inception drift-diffusion modeling with experimental measurements, provides a coherent picture explaining why multiple emitters sources systems do not lead to full ignition, and also exhibit conditions for which it does, leading to multiple emitters scalable systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Multiple emitters systems have been previously used so as to increase charge density in the drift region, many times without producing sensible increment neither in total current nor ionic wind. This contribution focuses on analyzing the detailed physics behind this failure, that is named 'multiple emitters un-scalability'. It is established that multiple emitters un-scalability is related to the inability of multiple corona discharge inceptions when increasing the emitter number and/or density. This confirms recent findings that corona discharge inception is shielded by electro-static interactions between emitters. This contribution demonstrates that this shielding can be balanced by emitter/collector electrostatic interactions depending on the considered configuration. For sufficiently close collector-emitter distances, ignition starts at the array center, whereas, on the contrary, when the collector is distant, the ignition not only starts at the array's periphery but might also be limited there. It is also demonstrated that emitter/emitter electrostatic interactions can be balanced by emitter/collector ones, depending of their chosen configuration. This lead to a variety of multi-inception patterns, the condition of which are analyzed. Intermediate configurations for which the collector is neither sufficiently close nor distant from the emitter array center provide a variety of multi-inception patterns that are hereby analyzed. Combining finite element computations of multi-inception drift-diffusion modeling with experimental measurements, provides a coherent picture explaining why multiple emitters sources systems do not lead to full ignition, and also exhibit conditions for which it does, leading to multiple emitters scalable systems.
2021
Coseru, Sergiu; Fabre, David; Plouraboué, Franck
Numerical study of ElectroAeroDynamic force and current resulting from ionic wind in emitter/collector systems Journal Article
In: Journal of Applied Physics, 129 (10), pp. 103304, 2021.
@article{oatao27560,
title = {Numerical study of ElectroAeroDynamic force and current resulting from ionic wind in emitter/collector systems},
author = {Sergiu Coseru and David Fabre and Franck Plouraboué},
url = {https://oatao.univ-toulouse.fr/27560/},
doi = {10.1063/5.0041061},
year = {2021},
date = {2021-03-01},
journal = {Journal of Applied Physics},
volume = {129},
number = {10},
pages = {103304},
publisher = {American Institute of Physics},
abstract = {ElectroAeroDynamic (EAD) propulsion has recently shown a growing interest with distinct propulsive capabilities and specific advantages. These experimental observations are, therefore, driving interest for numerical predictions of their propulsive capabilities. Keeping with a drift region description associated with the Kaptzov approximation of the corona discharge region effect, we evaluate the detailed contributions of EAD forces from electro-drift effects computation only. We propose a new regularization procedure for the numerical formulation of the electro-drift problem, allowing the convergence of the resulting iterative procedure (here a Newton method) over very large domains, using iteratively adapted meshes in high gradient regions. Our predictions show a good comparison with many experimental configurations, for both the current/intensity and the propulsive force. In some cases, we identify the air drag and the Kaptzov approximation to explain discrepancies with experimental measurements. Finally,},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
ElectroAeroDynamic (EAD) propulsion has recently shown a growing interest with distinct propulsive capabilities and specific advantages. These experimental observations are, therefore, driving interest for numerical predictions of their propulsive capabilities. Keeping with a drift region description associated with the Kaptzov approximation of the corona discharge region effect, we evaluate the detailed contributions of EAD forces from electro-drift effects computation only. We propose a new regularization procedure for the numerical formulation of the electro-drift problem, allowing the convergence of the resulting iterative procedure (here a Newton method) over very large domains, using iteratively adapted meshes in high gradient regions. Our predictions show a good comparison with many experimental configurations, for both the current/intensity and the propulsive force. In some cases, we identify the air drag and the Kaptzov approximation to explain discrepancies with experimental measurements. Finally,
Monrolin, Nicolas; Plouraboué, Franck
Multi-scale two-domain numerical modeling of stationary positive DC corona discharge/drift-region coupling Journal Article
In: Journal of Computational Physics, 443 , pp. 110517, 2021, ISSN: 0021-9991.
@article{MONROLIN2021110517,
title = {Multi-scale two-domain numerical modeling of stationary positive DC corona discharge/drift-region coupling},
author = {Nicolas Monrolin and Franck Plouraboué},
url = {https://www.sciencedirect.com/science/article/pii/S0021999121004125},
doi = {https://doi.org/10.1016/j.jcp.2021.110517},
issn = {0021-9991},
year = {2021},
date = {2021-01-01},
journal = {Journal of Computational Physics},
volume = {443},
pages = {110517},
abstract = {Corona discharge modeling mostly relies on two, mostly distinct, approaches: high-fidelity, numerically challenging, unsteady simulations having high-computational cost or low-fidelity simulations based on empirical assumptions such as constant electric field at the emitter electrode. For the purpose of steady discharge current predictions, high-fidelity models are very costly to use whilst empirical models have limited range of validity owing the subtle use of tuned parameters. We propose an intermediate approach: an asymptotic multi-scale/two-domain numerical modeling based upon generalizing previous asymptotic axi-symmetrical analysis [1], [2]. We show how the initial elliptic (electric potential), hyperbolic (charge transport), non-local (photo-ionization) problem can be formulated into two local problems coupled by matching conditions. The approach relies on a multipole expansion of the radiative photo-ionization source term (in two dimensions for cylindrical emitters). The analytical asymptotic matching conditions derived in [2] result in flux continuity conditions at the boundary of the two domains. These coupling conditions are enforced by Lagrange multipliers, within a variational formulation, leading to a hierarchy of non-linear coupled problems. The proposed approach is both monolithic and two-domains: two asymptotic regions, an inner-one associated with corona discharge, and an outer-one, the ion drift region. Numerical convergence and validations of the finite element implementation is provided. A comparison with various experimental results convincingly demonstrate the applicability of the method, which avoids tuning parameters dedicated to each specific configuration, but, on the contrary, exclusively relies on known and measurable physical quantities (e.g., ion mobilities, photo-ionization coefficient, ionization electric field, Townsend discharge coefficient, etc...).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Corona discharge modeling mostly relies on two, mostly distinct, approaches: high-fidelity, numerically challenging, unsteady simulations having high-computational cost or low-fidelity simulations based on empirical assumptions such as constant electric field at the emitter electrode. For the purpose of steady discharge current predictions, high-fidelity models are very costly to use whilst empirical models have limited range of validity owing the subtle use of tuned parameters. We propose an intermediate approach: an asymptotic multi-scale/two-domain numerical modeling based upon generalizing previous asymptotic axi-symmetrical analysis [1], [2]. We show how the initial elliptic (electric potential), hyperbolic (charge transport), non-local (photo-ionization) problem can be formulated into two local problems coupled by matching conditions. The approach relies on a multipole expansion of the radiative photo-ionization source term (in two dimensions for cylindrical emitters). The analytical asymptotic matching conditions derived in [2] result in flux continuity conditions at the boundary of the two domains. These coupling conditions are enforced by Lagrange multipliers, within a variational formulation, leading to a hierarchy of non-linear coupled problems. The proposed approach is both monolithic and two-domains: two asymptotic regions, an inner-one associated with corona discharge, and an outer-one, the ion drift region. Numerical convergence and validations of the finite element implementation is provided. A comparison with various experimental results convincingly demonstrate the applicability of the method, which avoids tuning parameters dedicated to each specific configuration, but, on the contrary, exclusively relies on known and measurable physical quantities (e.g., ion mobilities, photo-ionization coefficient, ionization electric field, Townsend discharge coefficient, etc...).
2018
Plouraboué, Franck
Flying with ionic wind Journal Article
In: Nature, 563 , pp. 476–477, 2018.
@article{oatao21207,
title = {Flying with ionic wind},
author = {Franck Plouraboué},
url = {https://oatao.univ-toulouse.fr/21207/},
doi = {10.1038/d41586-018-07411-z},
year = {2018},
date = {2018-11-01},
journal = {Nature},
volume = {563},
pages = {476--477},
publisher = {Nature Publishing Group},
abstract = {Aeroplanes use propellers and turbines, and are typically powered by fossil-fuel combustion. An alternative method of propelling planes has been demonstrated that does not require moving parts or combustion.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Aeroplanes use propellers and turbines, and are typically powered by fossil-fuel combustion. An alternative method of propelling planes has been demonstrated that does not require moving parts or combustion.
Monrolin, Nicolas
Étude théorique et expérimentale de la propulsion électrohydrodynamique dans l'air PhD Thesis
2018.
@phdthesis{oatao23644,
title = {Étude théorique et expérimentale de la propulsion électrohydrodynamique dans l'air},
author = {Nicolas Monrolin},
url = {https://oatao.univ-toulouse.fr/23644/},
year = {2018},
date = {2018-09-01},
abstract = {L'effet Biefeld-Brown, du nom de ses découvreurs dans les années 1920, désigne la force électrohydrodynamique (EHD) s'appliquant sur deux électrodes sous haute tension dans l'air. Si l'origine de cette force a pu faire l'objet de certaines spéculations, il est aujourd'hui admis qu'elle repose sur l'accélération par un fort champ électrique d'un volume d'air partiellement ionisé. Cet effet aussi appelé vent ionique intéresse diverses applications : contrôle actif d'écoulement, augmentation du transfert de chaleur par convection forcée, séchage de denrées alimentaires ou encore la propulsion. Cette thèse, présente une étude expérimentale, théorique et numérique du vent ionique dans une configuration modèle à deux électrodes parallèles. Le faible rendement du vent ionique l'a écarté des applications à la propulsion mais des expériences récentes menées en 2013 montrent qu'il permet d'atteindre un rapport poussée/puissance étonnement élevé. Nous montrons dans une première partie, à partir de mesures et de considérations aérodynamique générales que la poussée générée pourrait suffire à contrebalancer la force de traînée pour certains aéronefs ultra-légers. Ces mesures ont permis de quantifier la force EHD et sa dépendance avec la géométrie des électrodes. En outre, la meilleure configuration à deux collecteurs peut produire une poussée presque deux fois plus importante qu'une configuration avec un seul collecteur, à tension fixée. Ces premiers résultats ont été affinés dans un second temps par les mesures PIV qui ont permis la reconstruction de l'écoulement et du champ de force entre les électrodes. Les vitesses mesurées dépassent rarement 3 m/s, et la force volumique est de l'ordre de 10 N/m3. L'origine physique de la configuration optimale à deux collecteurs a été éclaircie par la mise en évidence des structures de sillages et de leurs effets instationnaires. Par ailleurs, une analyse théorique générale de la force propulsive nous a permis de confirmer sa dépendance explicite avec le rapport courant sur mobilité ionique. Le courant étant directement lié à la physique de la décharge couronne, la seconde partie de la thèse s'est concentrée sur son analyse théorique et numérique. Une analyse asymptotique a ainsi permis de trouver une expression analytique du champ électrique critique et de la caractéristique courant-tension permettant de connaître l'influence de la densité du gaz et de sa composition sur le courant produit dans des électrodes concentriques. Cette approche asymptotique a été associée à une formulation de décomposition de domaine dans le cadre d'une discrétisation par éléments finis pour analyser des configurations plus générales. Une résolution itérative du système d'équations stationnaires non-linéaire couplées par méthode de Newton est proposée, testée et validée. Cette méthode peut être étendue à des géométries plus complexes, permettant ainsi d'obtenir une condition d'injection des charges prenant en compte la physique complexe de la décharge.},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
L'effet Biefeld-Brown, du nom de ses découvreurs dans les années 1920, désigne la force électrohydrodynamique (EHD) s'appliquant sur deux électrodes sous haute tension dans l'air. Si l'origine de cette force a pu faire l'objet de certaines spéculations, il est aujourd'hui admis qu'elle repose sur l'accélération par un fort champ électrique d'un volume d'air partiellement ionisé. Cet effet aussi appelé vent ionique intéresse diverses applications : contrôle actif d'écoulement, augmentation du transfert de chaleur par convection forcée, séchage de denrées alimentaires ou encore la propulsion. Cette thèse, présente une étude expérimentale, théorique et numérique du vent ionique dans une configuration modèle à deux électrodes parallèles. Le faible rendement du vent ionique l'a écarté des applications à la propulsion mais des expériences récentes menées en 2013 montrent qu'il permet d'atteindre un rapport poussée/puissance étonnement élevé. Nous montrons dans une première partie, à partir de mesures et de considérations aérodynamique générales que la poussée générée pourrait suffire à contrebalancer la force de traînée pour certains aéronefs ultra-légers. Ces mesures ont permis de quantifier la force EHD et sa dépendance avec la géométrie des électrodes. En outre, la meilleure configuration à deux collecteurs peut produire une poussée presque deux fois plus importante qu'une configuration avec un seul collecteur, à tension fixée. Ces premiers résultats ont été affinés dans un second temps par les mesures PIV qui ont permis la reconstruction de l'écoulement et du champ de force entre les électrodes. Les vitesses mesurées dépassent rarement 3 m/s, et la force volumique est de l'ordre de 10 N/m3. L'origine physique de la configuration optimale à deux collecteurs a été éclaircie par la mise en évidence des structures de sillages et de leurs effets instationnaires. Par ailleurs, une analyse théorique générale de la force propulsive nous a permis de confirmer sa dépendance explicite avec le rapport courant sur mobilité ionique. Le courant étant directement lié à la physique de la décharge couronne, la seconde partie de la thèse s'est concentrée sur son analyse théorique et numérique. Une analyse asymptotique a ainsi permis de trouver une expression analytique du champ électrique critique et de la caractéristique courant-tension permettant de connaître l'influence de la densité du gaz et de sa composition sur le courant produit dans des électrodes concentriques. Cette approche asymptotique a été associée à une formulation de décomposition de domaine dans le cadre d'une discrétisation par éléments finis pour analyser des configurations plus générales. Une résolution itérative du système d'équations stationnaires non-linéaire couplées par méthode de Newton est proposée, testée et validée. Cette méthode peut être étendue à des géométries plus complexes, permettant ainsi d'obtenir une condition d'injection des charges prenant en compte la physique complexe de la décharge.
Monrolin, Nicolas; Praud, Olivier; Plouraboué, Franck
Electrohydrodynamic ionic wind, force field, and ionic mobility in a positive dc wire-to-cylinders corona discharge in air Journal Article
In: Physical Review Fluids, 3 (6), pp. 063701/1–063701/20, 2018.
@article{oatao20160,
title = {Electrohydrodynamic ionic wind, force field, and ionic mobility in a positive dc wire-to-cylinders corona discharge in air},
author = {Nicolas Monrolin and Olivier Praud and Franck Plouraboué},
url = {https://oatao.univ-toulouse.fr/20160/
https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.3.063701},
doi = {10.1103/PhysRevFluids.3.063701},
year = {2018},
date = {2018-06-01},
urldate = {2018-06-01},
journal = {Physical Review Fluids},
volume = {3},
number = {6},
pages = {063701/1--063701/20},
publisher = {Amercian Physical Society},
abstract = {Ionic wind refers to the acceleration of partially ionized air between two high-voltage electrodes. We study the momentum transfer from ions to air, resulting from ionic wind created by two asymmetric electrodes and producing a net thrust. This electrohydrodynamic (EHD) thrust, has already been measured in previous studies with digital scales. In this study, we provide more insights into the electrohydrodynamic momentum transfer for a wire-to-cylinder(s) positive dc corona discharge. We provide a simple and general theoretical derivation for EHD thrust, which is proportional to the current/mobility ratio and also to an effective distance integrated on the surface of the electrodes. By considering various electrode configurations, our investigation brings out the physical origin of previously obtained optimal configurations, associated with a better tradeoff between Coulomb forcing, friction occurring at the collector, and wake interactions. By measuring two-dimensional velocity fields using particle image velocimetry (PIV), we are able to evaluate the resulting local net force, including the pressure gradient. It is shown that the contribution of velocity fluctuations in the wake of the collecting electrode(s) must be taken into account to recover the net thrust. We confirm the proportionality between the EHD force and the current/mobility ratio experimentally, and evaluate the ion mobility from PIV measurements. A spectral analysis of the velocity fluctuations indicates a dominant frequency corresponding to a Strouhal number of 0.3 based on the ionic wind velocity and the collector size. Finally, the effective mobility of charge carriers is estimated by a PIV based method inside the drift region.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ionic wind refers to the acceleration of partially ionized air between two high-voltage electrodes. We study the momentum transfer from ions to air, resulting from ionic wind created by two asymmetric electrodes and producing a net thrust. This electrohydrodynamic (EHD) thrust, has already been measured in previous studies with digital scales. In this study, we provide more insights into the electrohydrodynamic momentum transfer for a wire-to-cylinder(s) positive dc corona discharge. We provide a simple and general theoretical derivation for EHD thrust, which is proportional to the current/mobility ratio and also to an effective distance integrated on the surface of the electrodes. By considering various electrode configurations, our investigation brings out the physical origin of previously obtained optimal configurations, associated with a better tradeoff between Coulomb forcing, friction occurring at the collector, and wake interactions. By measuring two-dimensional velocity fields using particle image velocimetry (PIV), we are able to evaluate the resulting local net force, including the pressure gradient. It is shown that the contribution of velocity fluctuations in the wake of the collecting electrode(s) must be taken into account to recover the net thrust. We confirm the proportionality between the EHD force and the current/mobility ratio experimentally, and evaluate the ion mobility from PIV measurements. A spectral analysis of the velocity fluctuations indicates a dominant frequency corresponding to a Strouhal number of 0.3 based on the ionic wind velocity and the collector size. Finally, the effective mobility of charge carriers is estimated by a PIV based method inside the drift region.
Monrolin, Nicolas; Praud, Olivier; Plouraboué, Franck
Revisiting the positive DC corona discharge theory: Beyond Peek's and Townsend's law Journal Article
In: Physics of Plasmas, 25 (6), pp. 063503/1–063503/14, 2018.
@article{oatao20116,
title = {Revisiting the positive DC corona discharge theory: Beyond Peek's and Townsend's law},
author = {Nicolas Monrolin and Olivier Praud and Franck Plouraboué},
url = {https://aip.scitation.org/doi/10.1063/1.5031780
https://oatao.univ-toulouse.fr/20116/},
doi = {10.1063/1.5031780},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {Physics of Plasmas},
volume = {25},
number = {6},
pages = {063503/1--063503/14},
publisher = {AIP Publishing},
abstract = {The classical positive Corona Discharge (CD) theory in cylindrical axisymmetric configuration is revisited in order to find analytically the influence of gas properties and thermodynamic conditions on the corona current. The matched asymptotic expansion of Durbin & Turyn of a simplified but self-consitent problem is performed and explicit analytical solutions are derived. The mathematical derivation permits to express a new positive DC corona current-voltage charachteristic, either chosing dimensionless or dimensional formulation. In dimensional variables the current voltage law and the corona inception voltage explicitly depends on electrodes size and on physical gas properties such as ionization and photoionization parameters. The analytical predictions are successfully confronted with experiments and with Peek's and Townsend's laws. An analytical expression of the corona inception voltage $$backslash$varphi_on$ is proposed, which depends on known values of the physical parameters without adjustable parameters. As a proof of consistency, the classical Townsend current-voltage law $I=C$backslash$varphi($backslash$varphi-$backslash$varphi_on)$ is retrieved by linearizing the non-dimensional analytical solution.
A brief parametric study showcases the interest of this analytical current model especially for exploring small corona wires or considering various thermodynamic conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The classical positive Corona Discharge (CD) theory in cylindrical axisymmetric configuration is revisited in order to find analytically the influence of gas properties and thermodynamic conditions on the corona current. The matched asymptotic expansion of Durbin & Turyn of a simplified but self-consitent problem is performed and explicit analytical solutions are derived. The mathematical derivation permits to express a new positive DC corona current-voltage charachteristic, either chosing dimensionless or dimensional formulation. In dimensional variables the current voltage law and the corona inception voltage explicitly depends on electrodes size and on physical gas properties such as ionization and photoionization parameters. The analytical predictions are successfully confronted with experiments and with Peek's and Townsend's laws. An analytical expression of the corona inception voltage $$backslash$varphi_on$ is proposed, which depends on known values of the physical parameters without adjustable parameters. As a proof of consistency, the classical Townsend current-voltage law $I=C$backslash$varphi($backslash$varphi-$backslash$varphi_on)$ is retrieved by linearizing the non-dimensional analytical solution.
A brief parametric study showcases the interest of this analytical current model especially for exploring small corona wires or considering various thermodynamic conditions.
2017
Monrolin, Nicolas; Plouraboué, Franck; Praud, Olivier
Electrohydrodynamic thrust for in-atmosphere propulsion Journal Article
In: AIAA Journal, 55 (12), pp. 4296–4305, 2017.
@article{oatao18415,
title = {Electrohydrodynamic thrust for in-atmosphere propulsion},
author = {Nicolas Monrolin and Franck Plouraboué and Olivier Praud},
url = {https://arc.aiaa.org/doi/10.2514/1.J055928
https://oatao.univ-toulouse.fr/18415/},
doi = {10.2514/1.J055928},
year = {2017},
date = {2017-01-01},
urldate = {2017-01-01},
journal = {AIAA Journal},
volume = {55},
number = {12},
pages = {4296--4305},
publisher = {American Institute of Aeronautics and Astronautics},
abstract = {The electrohydrodynamic thrust generated by wire-cylinder electrodes under high dc voltage is experimentally analyzed. Some recent experimental studies have shown that electrohydrodynamic thrusters produced by corona discharge and ionic wind are able to deliver high thrust-to-power ratio, which reopens prospects for electrohydrodynamic propulsion. From simple considerations based on ultralight aircraft mass, aerodynamics, battery mass, and experimental electrohydrodynamic thrust densities, their potential for applications is showcased. Furthermore, an experimental study is performed, for which the experimental observations are presented in terms of electric field and thrust density. This allows a simplified and synthetic presentation of propulsive properties. Various experimental biases have been identified and corrected. The measure of time-periodic oscillations of the airflow in the back of the thruster pinpoints a possible wake effect due to the impact of ionic wind on electrodes. The variations of the associated drag are studied when varying the position of the collecting electrodes. It is shown that aerodynamic losses can be significant in experimental electrohydrodynamic thrusters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The electrohydrodynamic thrust generated by wire-cylinder electrodes under high dc voltage is experimentally analyzed. Some recent experimental studies have shown that electrohydrodynamic thrusters produced by corona discharge and ionic wind are able to deliver high thrust-to-power ratio, which reopens prospects for electrohydrodynamic propulsion. From simple considerations based on ultralight aircraft mass, aerodynamics, battery mass, and experimental electrohydrodynamic thrust densities, their potential for applications is showcased. Furthermore, an experimental study is performed, for which the experimental observations are presented in terms of electric field and thrust density. This allows a simplified and synthetic presentation of propulsive properties. Various experimental biases have been identified and corrected. The measure of time-periodic oscillations of the airflow in the back of the thruster pinpoints a possible wake effect due to the impact of ionic wind on electrodes. The variations of the associated drag are studied when varying the position of the collecting electrodes. It is shown that aerodynamic losses can be significant in experimental electrohydrodynamic thrusters.
2011
Beaume, Cédric; Plouraboué, Franck; Bergeon, Alain; Knobloch, Edgar
Electrolyte Stability in a Nanochannel with Charge Regulation Journal Article
In: Langmuir, 27 (17), pp. 11187–11198, 2011.
@article{oatao5465,
title = {Electrolyte Stability in a Nanochannel with Charge Regulation},
author = {Cédric Beaume and Franck Plouraboué and Alain Bergeon and Edgar Knobloch},
url = {https://pubs.acs.org/doi/10.1021/la2018488
https://oatao.univ-toulouse.fr/5465/},
doi = {10.1021/la2018488},
year = {2011},
date = {2011-01-01},
urldate = {2011-01-01},
journal = {Langmuir},
volume = {27},
number = {17},
pages = {11187--11198},
publisher = {American Chemical Society},
abstract = {The stability of an electrolyte confined in one dimension between two solid surfaces is analyzed theoretically in the case where overlapping double layers produce nontrivial interactions. Within the Poisson Boltzmann Nernst Planck
description of the electrostatic interaction and transport of electrical charges, the presence of Stern layers can enrich the set of possible solutions.
Our analytical and numerical study of the stability properties of the trivial state of this system identified an
instability to a new antisymmetric state. This state is stable for a range of gap widths that depends on the Debye and Stern lengths, but for smaller gap widths, where the Stern layers overlap, a second transition takes place and the stable nontrivial solution diverges. The origin of this divergence is explained and its properties analyzed
using asymptotic techniques which are in good agreement with numerical results. The relevance of our results to confined electrolytes at nanometer scales is discussed in the context of energy storage in nanometric systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The stability of an electrolyte confined in one dimension between two solid surfaces is analyzed theoretically in the case where overlapping double layers produce nontrivial interactions. Within the Poisson Boltzmann Nernst Planck
description of the electrostatic interaction and transport of electrical charges, the presence of Stern layers can enrich the set of possible solutions.
Our analytical and numerical study of the stability properties of the trivial state of this system identified an
instability to a new antisymmetric state. This state is stable for a range of gap widths that depends on the Debye and Stern lengths, but for smaller gap widths, where the Stern layers overlap, a second transition takes place and the stable nontrivial solution diverges. The origin of this divergence is explained and its properties analyzed
using asymptotic techniques which are in good agreement with numerical results. The relevance of our results to confined electrolytes at nanometer scales is discussed in the context of energy storage in nanometric systems.
2009
Plouraboué, Franck; Chang, Hsueh-Chia
Symmetry breaking and electrostatic attraction between two identical surfaces Journal Article
In: Physical Review E, 79 (4), pp. 041404(1)–041404(9), 2009.
@article{oatao5468,
title = {Symmetry breaking and electrostatic attraction between two identical surfaces},
author = {Franck Plouraboué and Hsueh-Chia Chang},
url = {https://oatao.univ-toulouse.fr/5468/},
doi = {10.1103/PhysRevE.79.041404},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
journal = {Physical Review E},
volume = {79},
number = {4},
pages = {041404(1)--041404(9)},
publisher = {American Physical Society},
abstract = {By allowing the surface charge of one surface to affect the adsorption equilibrium of the other, we establish
the existence of a long-range attractive interaction between two identical surfaces in an electrolyte containing
polyvalent counterions with a mean-field Poisson-Boltzmann approach. A Stern electrostatic condition from
linearization of the mass-action adsorption isotherm is used to capture how polyvalent ion condensation affects and reverses the surface charge. We furthermore establish a direct mapping between this Stern-layer condition and previously derived modified mean-field formulations associated with correlated fluctuations theory. For a sufficiently potential-sensitive isotherm, antisymmetric charge inversion can occur to produce an attractive force that increases with decreasing ionic strengths. Analyses of a mass-action isotherm produce force-separation relations, including an exponential far-?eld force decay distinct but consistent with previously
proposed correlated fluctuation theories and in quantitative agreement with experimental data.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
By allowing the surface charge of one surface to affect the adsorption equilibrium of the other, we establish
the existence of a long-range attractive interaction between two identical surfaces in an electrolyte containing
polyvalent counterions with a mean-field Poisson-Boltzmann approach. A Stern electrostatic condition from
linearization of the mass-action adsorption isotherm is used to capture how polyvalent ion condensation affects and reverses the surface charge. We furthermore establish a direct mapping between this Stern-layer condition and previously derived modified mean-field formulations associated with correlated fluctuations theory. For a sufficiently potential-sensitive isotherm, antisymmetric charge inversion can occur to produce an attractive force that increases with decreasing ionic strengths. Analyses of a mass-action isotherm produce force-separation relations, including an exponential far-?eld force decay distinct but consistent with previously
proposed correlated fluctuation theories and in quantitative agreement with experimental data.
2008
Plouraboué F, Chang HC
Attraction between two similar particles in an electrolyte: effects of Stern layer absorption Journal Article
In: An Acad Bras Cienc., 82 (1), pp. 95-108, 2008, (PMID: 20209246).
@article{F2008,
title = {Attraction between two similar particles in an electrolyte: effects of Stern layer absorption},
author = {Plouraboué F, Chang HC},
url = {https://hal.archives-ouvertes.fr/file/index/docid/338932/filename/art_iutam.pdf},
doi = {10.1590/s0001-37652010000100009},
year = {2008},
date = {2008-11-14},
journal = {An Acad Bras Cienc.},
volume = {82},
number = {1},
pages = {95-108},
abstract = {When Debye length is comparable or larger than the distance between two identical particles, the overlapping among the particles double-layers can play an important role in their interactions. This paper presents a theoretical analysis of the interaction among two identical particles with overlapped double-layers. We particularly focus on the effect of a Stern electro static condition from linearization of the adsorption isotherm near the isoelectric (neutrality) point in order to capture how polyvalent ion condensation affect sand reverses the surface charge. The stationary potential problem is solved within the framework of an asymptotic lubrication approach for a mean-field Poisson-Boltzmann model. Both spherical and cylindrical particles are analyzed. The results are finally discussed in the context of Debye-Hückel (D-H) limit and beyond it.},
note = {PMID: 20209246},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
When Debye length is comparable or larger than the distance between two identical particles, the overlapping among the particles double-layers can play an important role in their interactions. This paper presents a theoretical analysis of the interaction among two identical particles with overlapped double-layers. We particularly focus on the effect of a Stern electro static condition from linearization of the adsorption isotherm near the isoelectric (neutrality) point in order to capture how polyvalent ion condensation affect sand reverses the surface charge. The stationary potential problem is solved within the framework of an asymptotic lubrication approach for a mean-field Poisson-Boltzmann model. Both spherical and cylindrical particles are analyzed. The results are finally discussed in the context of Debye-Hückel (D-H) limit and beyond it.
Lectures, interviews…
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Innovative aerospace propulsion techniques: participation in a French public radio broadcast
