Biefeld–Brown effect
Encyclopedia
The Biefeld–Brown effect is an electrical effect that produces an ionic wind that transfers its momentum to surrounding neutral particles, first discovered by Paul Alfred Biefeld
(Germany
) and Thomas Townsend Brown
(USA
). The effect is more widely referred to as electrohydrodynamics
(EHD) or sometimes electro-fluid-dynamics, a counterpart to the well-known magnetohydrodynamics
. Extensive research was performed during the 1950s and 1960s on the use of this electric propulsion effect during the publicized era of the United States gravity control propulsion research (1955 - 1974)
. Top secret experiments into the effect were also conducted in France
1955-1958 by Thomas Townsend Brown and SNCASO called Project Montgolfier. During 1964, Major Alexander Procofieff de Seversky
published much of his related work in , and with the aim to forestall any possible misunderstanding about these devices, termed these flying machines as ionocraft
s. In the following years, many promising concepts were abandoned due to technological limitations. The effect has only recently become of interest again and such flying devices are now known as EHD thrusters. Simple single-stage versions lifted by this effect are sometimes also called lifters.
The effect is generally believed to rely on corona discharge
, which allows air molecules to become ion
ized near sharp points and edges. Usually, two electrodes are used with a high voltage between them, ranging from a few kilovolts and up to megavolt levels, where one electrode is small or sharp, and the other larger and smoother. The most effective distance between electrodes occurs at an electric potential gradient of about 10 kV/cm, which is just below the nominal breakdown voltage of air between two sharp points, at a current density level usually referred to as the saturated corona current condition. This creates a high field gradient around the smaller, positively charged electrode. Around this electrode, ionization occurs, that is, electron
s are stripped from the atoms in the surrounding medium; they are literally pulled right off by the electrode's charge.
This leaves a cloud of positively charged ion
s in the medium, which are attracted to the negative smooth electrode by Coulomb's Law, where they are neutralized again. This produces an equally scaled opposing force in the lower electrode. This effect can be used for propulsion (see EHD thruster), fluid
pump
s and recently also in EHD cooling systems. The velocity achievable by such setups is limited by the momentum achievable by the ionized air, which is reduced by ion impact with neutral air. A theoretical derivation of this force has been proposed (see the external links below).
However, this effect works using either polarity for the electrodes: the small or thin electrode can be either positive or negative, and the larger electrode must have the opposite polarity. On many experimental sites it is reported that the thrust effect of a lifter is actually a bit stronger when the small electrode is the positive one. This is possibly an effect of the differences between the ionization energy and electron affinity energy of the constituent parts of air; thus the ease of which ions are created at the 'sharp' electrode.
As air pressure is removed from the system, several effects combine to reduce the force and momentum available to the system. The number of air molecules around the ionizing electrode is reduced, decreasing the quantity of ionized particles. At the same time, the number of impacts between ionized and neutral particles is reduced. Whether this increases or decreases the maximum momentum of the ionized air is not typically measured, although the force acting upon the electrodes reduces, until the glow discharge region is entered. The reduction in force is also a product of the reducing breakdown voltage of air, as a lower potential must be applied between the electrodes, thereby reducing the force dictated by Coulomb's Law.
During the glow discharge region, the air becomes a conductor. Though the applied voltage and current will propagate at nearly the speed of light, the movement of the conductors themselves is almost negligible. This leads to a Coulomb force and change of momentum so small as to be zero.
Below the glow discharge region, the breakdown voltage increases again, whilst the number of potential ions decreases, and the chance of impact lowers. Experiments have been conducted and found to both prove and disprove a force at very low pressure. It is likely that the reason for this is that at very low pressures, only experiments which used very large voltages produced positive results, as a product of a greater chance of ionization of the extremely limited number of available air molecules, and a greater force from each ion from Coulomb's Law; experiments which used lower voltages have a lower chance of ionization and a lower force per ion. Common to positive results is that the force observed is small in comparison to experiments conducted at standard pressure. This is likely to be the result of the massively reduced number of ions produced by the experiment, although this could also be interpreted to be a different force entirely.
Further experimentation is necessary to validate the new theory as opposed to the solution provided by Coulomb's Law.
An article by Martin Tajmar
(see below, or a summary) describes an experiment designed to test the possibility that this effect may need some other effect than ion winds for its explanation. No such effect was found, to the limit of experimental accuracy. In particular, no thrust could be observed in a vacuum. A similar device was tested in a vacuum in an episode of the Mythbusters
with the same result.
Critics and supporters alike have called throughout the years for vacuum experiments, in order to eliminate ion wind contributions from the devices. While there have been a handful of such experiments, most notably the efforts of Dr. R.L. Talley in the late 1980s and early 1990s, there is still a great deal of discrepancy over whether the effect is directly related to gravity or not, mainly because it isn't predicted by conventional electrostatics
or general relativity
.
s on his discovery:
Historically numerous patents have been granted for various applications of the effect, from electrostatic dust precipitation, to air ionizers, and also for flight. A particularly notable patent — — was granted to G.E. Hagen in 1964, for apparatus more or less identical to the later so called 'lifter' devices. Other ionic US patents of interest: 2022465, 2182751, 2282401, 2295152, 2460175, 2636664, 2765975, 3071705, 3177654, 3223038, 3120363, 3130945
Paul Alfred Biefeld
Dr. Paul Alfred Biefeld was born in Jöhstadt, Saxony, Germany. He was the son of Heinrich and Wilhelmina Biefeld, he moved to the United States in 1881. Biefeld received his B.S. in Electrical Engineering at the University of Wisconsin in 1894. He received his Ph.D...
(Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
) and Thomas Townsend Brown
Thomas Townsend Brown
Thomas Townsend Brown was an American physicist.-Early and middle years:Brown was born in Zanesville, Ohio; his parents were Lewis K. and Mary Townsend Brown. In 1921, Brown discovered what was later called the Biefeld-Brown effect while experimenting with a Coolidge X-ray tube. This is a vacuum...
(USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
). The effect is more widely referred to as electrohydrodynamics
Electrohydrodynamics
Electrohydrodynamics , also known as electro-fluid-dynamics or electrokinetics, is the study of the dynamics of electrically charged fluids. It is the study of the motions of ionised particles or molecules and their interactions with electric fields and the surrounding fluid...
(EHD) or sometimes electro-fluid-dynamics, a counterpart to the well-known magnetohydrodynamics
Magnetohydrodynamics
Magnetohydrodynamics is an academic discipline which studies the dynamics of electrically conducting fluids. Examples of such fluids include plasmas, liquid metals, and salt water or electrolytes...
. Extensive research was performed during the 1950s and 1960s on the use of this electric propulsion effect during the publicized era of the United States gravity control propulsion research (1955 - 1974)
United States gravity control propulsion research (1955 - 1974)
American interest in "gravity control propulsion research" intensified during the early 1950s. Literature from that period used the terms anti-gravity, anti-gravitation, baricentric, counterbary, electrogravitics , G-projects, gravitics, gravity control, and gravity propulsion...
. Top secret experiments into the effect were also conducted in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
1955-1958 by Thomas Townsend Brown and SNCASO called Project Montgolfier. During 1964, Major Alexander Procofieff de Seversky
Alexander Procofieff de Seversky
Alexander Nikolaievich Prokofiev de Seversky was a Russian-American aviation pioneer, inventor, and influential advocate of strategic air power.-Early life:...
published much of his related work in , and with the aim to forestall any possible misunderstanding about these devices, termed these flying machines as ionocraft
Ionocraft
An ionocraft or ion-propelled aircraft, commonly known as a lifter or hexalifter, is an electrohydrodynamic device to produce thrust in the air, without requiring any combustion or moving parts. The term "Ionocraft" dates back to the 1960s, an era in which EHD experiments were at their peak...
s. In the following years, many promising concepts were abandoned due to technological limitations. The effect has only recently become of interest again and such flying devices are now known as EHD thrusters. Simple single-stage versions lifted by this effect are sometimes also called lifters.
Effect analysis
Corona discharge
In electricity, a corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor that is electrically energized...
, which allows air molecules to become ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
ized near sharp points and edges. Usually, two electrodes are used with a high voltage between them, ranging from a few kilovolts and up to megavolt levels, where one electrode is small or sharp, and the other larger and smoother. The most effective distance between electrodes occurs at an electric potential gradient of about 10 kV/cm, which is just below the nominal breakdown voltage of air between two sharp points, at a current density level usually referred to as the saturated corona current condition. This creates a high field gradient around the smaller, positively charged electrode. Around this electrode, ionization occurs, that is, electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
s are stripped from the atoms in the surrounding medium; they are literally pulled right off by the electrode's charge.
This leaves a cloud of positively charged ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
s in the medium, which are attracted to the negative smooth electrode by Coulomb's Law, where they are neutralized again. This produces an equally scaled opposing force in the lower electrode. This effect can be used for propulsion (see EHD thruster), fluid
Fluid
In physics, a fluid is a substance that continually deforms under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids....
pump
Pump
A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
s and recently also in EHD cooling systems. The velocity achievable by such setups is limited by the momentum achievable by the ionized air, which is reduced by ion impact with neutral air. A theoretical derivation of this force has been proposed (see the external links below).
However, this effect works using either polarity for the electrodes: the small or thin electrode can be either positive or negative, and the larger electrode must have the opposite polarity. On many experimental sites it is reported that the thrust effect of a lifter is actually a bit stronger when the small electrode is the positive one. This is possibly an effect of the differences between the ionization energy and electron affinity energy of the constituent parts of air; thus the ease of which ions are created at the 'sharp' electrode.
As air pressure is removed from the system, several effects combine to reduce the force and momentum available to the system. The number of air molecules around the ionizing electrode is reduced, decreasing the quantity of ionized particles. At the same time, the number of impacts between ionized and neutral particles is reduced. Whether this increases or decreases the maximum momentum of the ionized air is not typically measured, although the force acting upon the electrodes reduces, until the glow discharge region is entered. The reduction in force is also a product of the reducing breakdown voltage of air, as a lower potential must be applied between the electrodes, thereby reducing the force dictated by Coulomb's Law.
During the glow discharge region, the air becomes a conductor. Though the applied voltage and current will propagate at nearly the speed of light, the movement of the conductors themselves is almost negligible. This leads to a Coulomb force and change of momentum so small as to be zero.
Below the glow discharge region, the breakdown voltage increases again, whilst the number of potential ions decreases, and the chance of impact lowers. Experiments have been conducted and found to both prove and disprove a force at very low pressure. It is likely that the reason for this is that at very low pressures, only experiments which used very large voltages produced positive results, as a product of a greater chance of ionization of the extremely limited number of available air molecules, and a greater force from each ion from Coulomb's Law; experiments which used lower voltages have a lower chance of ionization and a lower force per ion. Common to positive results is that the force observed is small in comparison to experiments conducted at standard pressure. This is likely to be the result of the massively reduced number of ions produced by the experiment, although this could also be interpreted to be a different force entirely.
Further experimentation is necessary to validate the new theory as opposed to the solution provided by Coulomb's Law.
An article by Martin Tajmar
Martin Tajmar
Martin Tajmar is a research scientist and project manager in the Space Propulsion group at Austrian Research Center Seibersdorf. He has research interests in new space propulsion systems, and possible connections between gravity and superconductivity....
(see below, or a summary) describes an experiment designed to test the possibility that this effect may need some other effect than ion winds for its explanation. No such effect was found, to the limit of experimental accuracy. In particular, no thrust could be observed in a vacuum. A similar device was tested in a vacuum in an episode of the Mythbusters
MythBusters
MythBusters is a science entertainment TV program created and produced by Beyond Television Productions for the Discovery Channel. The series is screened by numerous international broadcasters, including Discovery Channel Australia, Discovery Channel Latin America, Discovery Channel Canada, Quest...
with the same result.
Critics and supporters alike have called throughout the years for vacuum experiments, in order to eliminate ion wind contributions from the devices. While there have been a handful of such experiments, most notably the efforts of Dr. R.L. Talley in the late 1980s and early 1990s, there is still a great deal of discrepancy over whether the effect is directly related to gravity or not, mainly because it isn't predicted by conventional electrostatics
Electrostatics
Electrostatics is the branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges....
or general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
.
Patents
T. T. Brown was granted a number of patentPatent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
s on his discovery:
- GB300311 — A method of and an apparatus or machine for producing force or motion (accepted 1928-11-15) — Electrostatic motor (1934-09-25) — Electrokinetic apparatus (1960-08-16) — Electrokinetic transducer (1962-01-23) — Electrokinetic generator (1962-02-20) — Electrokinetic apparatus (1965-06-01) — Electric generator (1965-07-20)
Historically numerous patents have been granted for various applications of the effect, from electrostatic dust precipitation, to air ionizers, and also for flight. A particularly notable patent — — was granted to G.E. Hagen in 1964, for apparatus more or less identical to the later so called 'lifter' devices. Other ionic US patents of interest: 2022465, 2182751, 2282401, 2295152, 2460175, 2636664, 2765975, 3071705, 3177654, 3223038, 3120363, 3130945
External links
- Defying Gravity: The Parallel Universe of T. Townsend Brown - authorized biography on T. Townsend Brown
- The Hunt for Zero Point - book by Jane's Aviation editor Nick Cook
- Projet Montgolfier Reports, 1955-58
- http://www.youtube.com/watch?v=RKonAZvT2no - Video of the effect
Biefeld Brown effect electrohydrodynamics
- Blaze Labs Research: What is an EHD thruster? — Introduction on EHD thrusters, ionocrafts, lifters and lots of related information
- NASA: Asymmetrical Capacitors for Propulsion (PDF)
- Army Research Laboratory, Thomas B. Bahder:Force on an Asymmetric Capacitor