arXiv subjects

Alexandre A. Martins

Publications and source records attributed to Alexandre A. Martins.

11 recordsLinked to original sources

arXiv2012

X-Ray Propulsor: Physical Principle for an Electromagnetic Propellantless Propulsion System

In this work we are going to develop a physical model that explains how propulsion may be developed in a vacuum by the collision of electrons with an anode. Instead of using principles related to the conservation of only the mechanical momentum to achieve propulsion, like all the current propulsion systems do, the present system achieves propulsion by using principles related to the conservation of the canonical momentum. The complete physical model will be provided and comparison with preliminary experimental results will be performed. These results are important since they show that it is possible to achieve a radical different propulsion system with many advantages.

physics.class-ph↗

arXiv2012

Modeling of an improved positive corona thruster and actuator

In this work we are going to perform a simulation of a positive corona discharge in nitrogen gas, using two different asymmetric capacitor geometries. This work represents an improvement over previous work in order to accomplish higher ion wind velocities as well as stronger electrostatic propulsion forces on all the involved electrodes. In our model, the used positive ion source is a small diameter wire, which generates a positive corona discharge in nitrogen gas directed to the ground (or negatively charged) electrodes. By applying the fluid dynamic and electrostatic theories, all hydrodynamic and electrostatic forces that act on the considered geometries will be computed in an attempt to demonstrate the greater performance of the new developed geometries.

physics.plasm-ph↗

arXiv2012

Fluidic Electrodynamics: On parallels between electromagnetic and fluidic inertia

The purpose of the present work is to trace parallels between the known inertia forces in fluid dynamics with the inertia forces in electromagnetism that are known to induce resistance forces on masses both due to acceleration and at constant velocity. It is shown that the force exerted on a particle by an ideal fluid produces two effects: i) resistance to acceleration and, ii) an increase of mass with velocity. These resistance forces arise due to the fluid dragged by the particle, where the bare mass of the particle at rest changes when in motion ("dressed" particle). It is demonstrated that the vector potential created by a charged particle in motion acts as an ideal space flow that surrounds the particle. The interaction between the particle and the entrained space flow gives rise to the observed properties of inertia and the relativistic increase of mass. Parallels are made between the inertia property of matter, electromagnetism and the hydrodynamic drag in potential flow. Accordingly, in this framework the non resistance of a particle in uniform motion through an ideal fluid (D'Alembert's paradox) corresponds to Newton's first law. The law of inertia suggests that the physical vacuum can be modeled as an ideal fluid, agreeing with the space-time ideal fluid approach from general relativity.

physics.flu-dyn↗

arXiv2012

Simulation of a wire-cylinder-plate positive corona discharge in nitrogen gas at atmospheric pressure

In this work we are going to perform a simulation of a wire-cylinder-plate positive corona discharge in nitrogen gas, and compare our results with already published experimental results in air for the same structure. We have chosen to simulate this innovative geometry because it has been established experimentally that it can generate a thrust per unit electrode length transmitted to the gas of up to 0.35 N/m and is also able to induce an ion wind top velocity in the range of 8-9 m/s in air. In our model, the used ion source is a small diameter wire, which generates a positive corona discharge in nitrogen gas directed to the ground electrode, after which the generated positive ions are further accelerated in the acceleration channel between the ground and cathode. By applying the fluid dynamic and electrostatic theories all hydrodynamic and electrostatic forces that act on the considered geometries will be computed in an attempt to theoretically confirm the generated ion wind profile and also the thrust per unit electrode length. These results are important to establish the validity of this simulation tool for the future study and development of this effect for practical purposes.

physics.plasm-ph↗

arXiv2011

Modeling of an EHD corona flow in nitrogen gas using an asymmetric capacitor for propulsion

The present work intends to identify the nature of the propulsive force that occurs during a positive corona discharge in nitrogen gas using an asymmetric capacitor geometry. We are going to apply the known theory of electrohydrodynamics (EHD) and electrostatics in order to compute all hydrodynamic and electrostatic forces that act on the considered geometry in an attempt to provide a physical insight on the force mechanism that acts on an asymmetrical capacitor.

physics.plasm-ph↗

arXiv2011

On the influence that the ground electrode diameter has in the propulsion efficiency of an asymmetric capacitor in nitrogen gas

In this work the propulsion force developed in an asymmetric capacitor will be calculated for three different diameters of the ground electrode. The used ion source is a small diameter wire, which generates a positive corona discharge in nitrogen gas directed to the ground electrode. By applying the fluid dynamic and electrostatic theories all hydrodynamic and electrostatic forces that act on the considered geometries will be computed in an attempt to provide a physical insight on the force mechanism that acts on the asymmetrical capacitors, and also to understand how to increase the efficiency of propulsion.

physics.plasm-ph↗

arXiv2010

Study on the influence that the number of positive ion sources has in the propulsion efficiency of an asymmetric capacitor in nitrogen gas

The present work intends to compare the propulsion force developed in an asymmetric capacitor, according to the number of positive ion sources used. The ion source is a corona wire, which generates a positive corona discharge in nitrogen gas directed towards the ground electrode. We are going to apply the known theory of electrohydrodynamics (EHD) and electrostatics in order to compute all hydrodynamic and electrostatic forces that act on the considered geometry in an attempt to provide a physical insight on the force mechanism that acts on each asymmetrical capacitor, and also to compare propulsion efficiencies.

physics.plasm-ph↗

arXiv2009

Electrical and Kinetic Model of an Atmospheric RF Device for Plasma Aerodynamics Applications

The asymmetrically mounted flat plasma actuator is studied using a self-consistent 2-DIM fluid model at atmospheric pressure. The computational model use the drift-diffusion approximation and a simple plasma phenomenological kinetic model. It is investigated its electrical and kinetic properties, and calculated the charged species concentrations, surface charge density, electrohydrodynamic forces and gas speed. The present computational model contributes to understand the main physical mechanisms and methods to improve its performance.

physics.plasm-ph↗

arXiv2009

Fluidic Electrodynamics: a new approach to EM Propulsion

We report on a new methodological approach to electrodynamics based on a fluidic viewpoint. We develop a systematic approach establishing analogies between physical magnitudes and isomorphism (structure-preserving mappings) between systems of equations. This methodological approach allows us to give a general expression for the hydromotive force, thus re-obtaining the Navier-Stokes equation departing from the an appropriate electromotive force. From this ground we offer a fluidic approach to different kind of issues with interest in propulsion, e.g., the force exerted by a charged particle on a body carrying current; the magnetic force between two parallel currents; the Magnus's force. It is shown how the intermingle between the fluid vectors fields and electromagnetic fields lead to new insights on their dynamics. The new concepts introduced in this work suggest possible applications to electromagnetic (EM) propulsion devices and the mastery of the principles of producing electric fields of required configuration in plasma medium.

physics.flu-dyn↗

arXiv2008

On the electromagnetic origin of inertia and inertial mass

We address the problem of inertial property of matter through analysis of the motion of an extended charged particle. Our approach is based on the continuity equation for momentum (Newton's second law) taking due account of the vector potential and its convective derivative. We obtain a development in terms of retarded potentials allowing an intuitive physical interpretation of its main terms. The inertial property of matter is then discussed in terms of a kind of induction law related to the extended charged particle's own vector potential. Moreover, it is obtained a force term that represents a drag force acting on the charged particle when in motion relatively to its own vector potential field lines. The time rate of variation of the particle's vector potential leads to the acceleration inertia reaction force, equivalent to the Schott term responsible for the source of the radiation field. We also show that the velocity dependent term of the particle's vector potential is connected with the relativistic increase of mass with velocity and generates a longitudinal stress force that is the source of electric field lines deformation. In the framework of classical electrodynamics, we have shown that the electron mass has possibly a complete electromagnetic origin and the obtained covariant equation solves the "4/3 mass paradox" for a spherical charge distribution.

physics.class-ph↗

arXiv2006

The Connection Between Inertial Forces and the Vector Potential

. The inertia property of matter is discussed in terms of a type of induction law related to the extended charged particle's own vector potential. Our approach is based on the Lagrangian formalism of canonical momentum writing Newton's second law in terms of the vector potential and a development in terms of obtaining retarded potentials, that allow an intuitive physical interpretation of its main terms. This framework provides a clear physical insight on the physics of inertia. It is shown that the electron mass has a complete electromagnetic origin and the covariant equation obtained solves the "4/3 mass paradox". This provides a deeper insight into the significance of the main terms of the equation of motion. In particular a force term is obtained from the approach based on the continuity equation for momentum that represents a drag force the charged particle feels when in motion relatively to its own vector potential field lines. Thus, the time derivative of the particle's vector potential leads to the acceleration inertia reaction force and is equivalent to the Schott term responsible for the source of the radiation field. We also show that the velocity dependent term of the particle's vector potential is connected with the relativistic increase of mass with velocity and generates a stress force that is the source of electric field lines deformation. This understanding broadens the possibility to manipulate inertial mass and potentially suggests some mechanisms for possible applications to electromagnetic propulsion and the development of advanced space propulsion physics.

physics.class-ph↗