- #1
slow
- 93
- 16
I want to expose something that caused me a lot of curiosity. First of all, I beg you to point out my mistakes and, if there are any insurmountable ones, help me to understand them. I start by presenting a figure.
It is a solenoid that differs from the common case, because the wire at one end enters the interior and takes the place of the axis. I propose to denominate coaxial inductor to that device. In the graph the turns appear very separated, to be able to show the stretch of wire that occupies the axis. In practice the turns would be together, separated only by the insulating layer of the wire.
The idea is to understand how the electric field, the magnetic field and the Poynting vector are arranged inside the solenoid. The outside fields will be mentioned in the last part of the note.
DC operation shows that the Poynting vector has more than one component. The graph shows two, which are obvious. There is more ? I don't know. I will take those two into account.
The magnetic field has a solenoidal component. With turns together, the lines of this component differ little, in first approximation, from straight lines parallel to the axis. They are slightly wavy lines, which differ a bit from rectitude. In the first approach I will take them as straight lines parallel to the axis. Component ##B_1## has that address.
The current that passes through the section of wire located on the axis produces another component of the magnetic field, whose field lines are circles centered on the axis. One of them is represented as a clear ring around the axis. The component ##B_2## is tangent to one of those circles.
The turns, traversed by the current, result in a tube-shaped zone where there is always electric charge present. This load produces a net electric field equal to zero inside the coaxial inductor. This is fulfilled in first approximation, whatever the value of the load. That is why it would be fulfilled even if we connect the inductor to an AC generator.
There is also a charge present in the section of wire located on the shaft. This charge produces a non-zero net electric field, which is the only component of the electric field inside the coaxial inductor, symbolized E.
With two components of the magnetic field and one of the electric field, the Poynting vector has two components, ##S_1## and ##S_2##.
##S_1## corresponds to energy rotating around the axis. ##S_2## corresponds to energy movement in the axial direction. The resulting Poynting vector corresponds to energy that rotates around the axis while advancing in the axial direction. If we apply the mass / energy ratio, we will have a mass inside the solenoid that behaves like the bullet of a weapon, which rotates as it advances, because inside the barrel there is a helical groove.
The battery provides constant current. Although the Poynting vector has these components, the coaxial inductor can not radiate energy into the surrounding space, since constant fields do not produce electromagnetic waves. And within my experience, I never knew that a configuration of constant fields could maintain their properties while traveling through space autonomously.
What would happen if we connect the coaxial inductor to a radiofrequency generator? The field ##E## and the components of ##B## would undergo module and direction variations, but the Poynting vector would always have a rotating component and an axial component.
Where there are fields varying there is emission of electromagnetic waves. In this case we would also expect them be emitted. And if they are issued, do they exhibit some property that does not appear when we use conventional antennas?
Outside the solenoid, ##B## is not parallel to the axis, nor near to be parallel . Those lines of the magnetic field are curved and scattered throughout the surrounding space. In that region ##B## has a radial and an axial component. The electric field is radial, because the entire load is housed in a zone that has the shape of a tube.
The direction of the external axial component is opposite to the direction of ##B_1##. The external axial component and the electric field determine a component of the Poyting vector that corresponds to the rotation of the energy, in the opposite direction to the internal rotation. That's fine, because the opposite case would violate the conservation of angular momentum.
The radial field and the electric field on the outside determine an axial component of the Poynting vector, whose direction is opposite to the direction of the internal axial component. That is fine, because the opposite case would violate the conservation of the quantity of the linear moment.
This is simply an attempt at first approximation. It could contain insurmountable errors. In case of not containing them, the operation in radiofrequency has something interesting. Inside and outside the solenoid there is energy that turns and advances. But the exterior and the interior do it in opposite senses, as the action is an electrodynamic punch that divides something in two parts, opposite and complementary. Both parties need each other to fulfill the conservation, but can not remain mutually at rest. That event seems like a cylindrical tear of space, in the region where the phenomenon occurs.
It is a solenoid that differs from the common case, because the wire at one end enters the interior and takes the place of the axis. I propose to denominate coaxial inductor to that device. In the graph the turns appear very separated, to be able to show the stretch of wire that occupies the axis. In practice the turns would be together, separated only by the insulating layer of the wire.
The idea is to understand how the electric field, the magnetic field and the Poynting vector are arranged inside the solenoid. The outside fields will be mentioned in the last part of the note.
DC operation shows that the Poynting vector has more than one component. The graph shows two, which are obvious. There is more ? I don't know. I will take those two into account.
The magnetic field has a solenoidal component. With turns together, the lines of this component differ little, in first approximation, from straight lines parallel to the axis. They are slightly wavy lines, which differ a bit from rectitude. In the first approach I will take them as straight lines parallel to the axis. Component ##B_1## has that address.
The current that passes through the section of wire located on the axis produces another component of the magnetic field, whose field lines are circles centered on the axis. One of them is represented as a clear ring around the axis. The component ##B_2## is tangent to one of those circles.
The turns, traversed by the current, result in a tube-shaped zone where there is always electric charge present. This load produces a net electric field equal to zero inside the coaxial inductor. This is fulfilled in first approximation, whatever the value of the load. That is why it would be fulfilled even if we connect the inductor to an AC generator.
There is also a charge present in the section of wire located on the shaft. This charge produces a non-zero net electric field, which is the only component of the electric field inside the coaxial inductor, symbolized E.
With two components of the magnetic field and one of the electric field, the Poynting vector has two components, ##S_1## and ##S_2##.
##S_1## corresponds to energy rotating around the axis. ##S_2## corresponds to energy movement in the axial direction. The resulting Poynting vector corresponds to energy that rotates around the axis while advancing in the axial direction. If we apply the mass / energy ratio, we will have a mass inside the solenoid that behaves like the bullet of a weapon, which rotates as it advances, because inside the barrel there is a helical groove.
The battery provides constant current. Although the Poynting vector has these components, the coaxial inductor can not radiate energy into the surrounding space, since constant fields do not produce electromagnetic waves. And within my experience, I never knew that a configuration of constant fields could maintain their properties while traveling through space autonomously.
What would happen if we connect the coaxial inductor to a radiofrequency generator? The field ##E## and the components of ##B## would undergo module and direction variations, but the Poynting vector would always have a rotating component and an axial component.
Where there are fields varying there is emission of electromagnetic waves. In this case we would also expect them be emitted. And if they are issued, do they exhibit some property that does not appear when we use conventional antennas?
Outside the solenoid, ##B## is not parallel to the axis, nor near to be parallel . Those lines of the magnetic field are curved and scattered throughout the surrounding space. In that region ##B## has a radial and an axial component. The electric field is radial, because the entire load is housed in a zone that has the shape of a tube.
The direction of the external axial component is opposite to the direction of ##B_1##. The external axial component and the electric field determine a component of the Poyting vector that corresponds to the rotation of the energy, in the opposite direction to the internal rotation. That's fine, because the opposite case would violate the conservation of angular momentum.
The radial field and the electric field on the outside determine an axial component of the Poynting vector, whose direction is opposite to the direction of the internal axial component. That is fine, because the opposite case would violate the conservation of the quantity of the linear moment.
This is simply an attempt at first approximation. It could contain insurmountable errors. In case of not containing them, the operation in radiofrequency has something interesting. Inside and outside the solenoid there is energy that turns and advances. But the exterior and the interior do it in opposite senses, as the action is an electrodynamic punch that divides something in two parts, opposite and complementary. Both parties need each other to fulfill the conservation, but can not remain mutually at rest. That event seems like a cylindrical tear of space, in the region where the phenomenon occurs.