GB2467114A - Reactionless electric-field thruster - Google Patents

Abstract

The invention consists of a reaction-less thrust engine (or thruster) which can be built into any vehicle for land, sea, air, or space transport. Construction is based on a plurality of pairs of concentric cylindrical electrode sectors 1,2 embedded in high dielectric strength insulators and combined into layers, as indicated in Fig 4. It has no moving parts, produces no noise and does not require any propellant to be ejected, but is propelled solely by shaped electric fields 4 assisted by choice of different dielectrics 5,6.. The power requirement is a DC or low frequency AC voltage supply in the range of thousands to tens of thousands of volts to produce a high thrust force and low current to compensate leakage current of the insulating dielectric materials and perhaps to provide accelerating power. Fig 5 shows a further layered arrangement comprising semi-circular section assembled in a sinusoidal manner.

Description

REACTIONLESS ELECTRIC FIELD THRUSTER

This invention is that of a practical high thrust engine (or thruster) requiring neither propellant, nor reaction force from the environment. It takes advantage solely of the relatively well-known electrostatic field equations between pairs of substantially concentric cylindrical or spherical electrodes separated by high voltage dielectrics and so will work in a vacuum environment. Setting aside edge field effects outside the main electrode gap, these equations also apply approximately to sectors thereof.

With two exceptions 1,2+3, it seems to have been overlooked that these divergent fields in conjunction with suitably deployed dielectrics are capable of generating unequal attractive forces between oppositely charged semi-cylindrical or hemi-spherical electrodes and hence a non-zero resultant force on attached pairs. Therefore, they can achieve propulsion without requiring a propellant. Obviously, this is a vital advantage, especially for manned space flights, both to achieve earth orbit and for long distance space travel, as well as for most terrestrial applications. However, these shapes on their own are insufficient to produce practical high strength thrust engines for transport, unless configured appropriately with two or more dielectrics and utilised as basic structural elemçnts of repeated structures, which together are the essence of this invention.

Although concentric spherical electrode sectors behave much as cylindrical sectors, problems of fabrication of repeating structures and of electrical power connection seem less straightforward and they appear to offer no decisive advantages in terms of thrust levels, making cylindrical sectors the preferred choice. A further choice lies between coaxial and nested but offset (i.e. bipolar) cylinders. Calculations show that despite the asymmetric form of the bipolar geometry, the attractive forces between different sized full cylinders (surrounding either the same pole, or separate poles) are equal and so different dielectrics are still necessary to break this symmetry. Thus, coaxial cylindrical sectors have the advantage of simplicity and compactness because their electrode gap can be arranged to be the same as the smallest bipolar gap.

According to the present invention there is provided a reaction-less thrust engine (or thruster), constructed from a plurality of concentric contiguous cylindrical high voltage ( 1 -> 50 KV) DC or low frequency AC capacitor elements, or sectors thereof, which produce divergent fields by virtue of their geometry, and by incorporating insulators with different dielectric constants in the electrode gaps, will produce maximum thrust in a desired direction and decreased thrust in unwanted directions, mounted in a layer or layers, so as to provide a compact efficient propellant-less thruster.

A brief explanation of the theory and a specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-Fig. 1 shows a 3D perspective cut-away sketch of a full cylindrical capacitor with an annular dielectric layer.

Fig. 2 shows a cross section of a semi-cylindrical thruster element with a single dielectric.

Fig. 3 shows a cross-sectional view of a full cylindrical thruster element with two dielectrics.

Fig. 4 illustrates a cross-sectional view of a multiple cylinder first embodiment of the invention with two dielectrics.

Fig. 5 illustrates a cross-sectional view of a multiple corrugated sheet second embodiment of the invention with two dielectrics.

Fig. 1 shows a 3D perspective sketch of a full cylindrical capacitor consisting of two thin concentric cylindrical electrodes of radii r=a, and r=d (labelled) with voltage difference V volts and axial length L. Concentric with these and lying between them is a cylindrical shell of dielectric constant ic, with inner and outer radii of rb and r=c (also labelled) and of length L. If the charges on the electrodes are +q and -q, then from Gauss's law the electric field in free space E at radius r between the electrodes (in MKS units) is: E = _________ where c0 is the permittivity of free space.

2 it c0 r L Therefore, the voltage difference V between the electrodes, is given by: V = E. dr = ______ [(mb -ma) + (inc -mb) + (md -mc)] 2ir0L K = ______ [in(d/a) -(1 -.1) In(c/b)] 2it.g0L K Although the analysis will not be carried through here, the advantage of initially considering the dielectric to be separated by an air, or vacuum gap, from the electrodes is as follows. It allows one to see that small gaps filled with dielectric material with a lower K value than the main insulator (even adhesives or insulating oil) are at risk of electrical breakdown because a disproportionate fraction of the voltage V will appear across them leading to electrical breakdown. It also allows one to see that whereas the greatest thrust is on the inner electrode and is in an outward radial direction, there is also an inward thrust on the dielectric (which needs to be allowed for), directed inwards towards the region of higher E-field. However, the net thrust on the assembly is still outwards and increased by the permittivity of the dielectric.

If now we consider the situation of central interest, where the dielectric completely fills the gap i.e. b=a, cd then this simplifies the algebra and the force on the dielectric is automatically included by being part of the electrode-dielectric interface. The voltage then becomes: V ______ In(dla) 2 it K E0 L The corresponding total stored energy W is just Y2CV2 where C is the capacitance (qN) and so the outward pressure (= radial force! area 2itaL) acting on the inner electrode (radius a) is given by the partial radial derivative at constant V: Pradial(a) 1 Ô [CV] C2V2 5 [1] K 2ira L ôa[ 2] 4itaL äa[ C] 2[In(d/a)]2a2 An alternative and slightly more direct method of calculation of Pradial(a) giving precisely the same result is from the product of E-field and charge density. Thus: Pradial(a) E = &E2 = K C0 V2 2 2 2[ln(dla)]2a2 Evidently, due to symmetry, the total integrated force on this full cylindrical electrode is zero; a similar equation and conclusion apply to the outer electrode.

If we now consider the geometry of a semi-cylindrical thruster, shown in cross section in Fig.2 with the electrodes labelled 1 and 2, with radii a and d respectively and having a voltage difference V volts. The equipotential contours labelled 3 and electric field arrows labelled 4, between the electrodes are also shown. The total upward vertical thrust acting on the inner semi-cylindrical electrode, setting aside fields outside the main gap, may be obtained by integrating the corresponding vertical force components over an appropriate circumferential range of ita metres and length L: Fvertical(a) L V2 * 2 51r12 cos(O) dO L V2 2 [ln(dla)]2a [ln(d!a)]2a Similarly, the downward thrust on the outer electrode: Fvertical(d) -icc L V2 *2 j2 cos(O) dO -j L V2 2[In(d/a)]2d [In(dla)J2d As may be seen, due to the divergent E-field flux in this electrode geometry, the above force components are unequal (oc 1!r, neglecting the common ln(dla) term). Ignoring stray fields outside the electrode gap, gives rise to a resultant upward propulsion force, Ftotal jç L V2 * (d -a) [ln(dla)]2 ad Whilst this semi-cylindrical geometry demonstrates the principle of a reaction-less thruster building block, as an isolated element, it suffers drawbacks of high stray fields (Fig.2), which are hard to calculate, from the sharp lower edges of the electrodes. This leads to strong but localised downward thrust forces, which oppose and largely nulIify the required propulsion; the edges are also likely to generate corona.

However, with appropriate contiguous combinations of the semi-cylindrical building blocks, these edges and their drawbacks, largely can be eliminated. Fig. 3 shows a cross-sectional view of the totally straightforward combination returning us to complete coaxial cylindrical electrodes, which then eliminates the troubles9me edges, but of course also eliminates the thrust.

However, by introducing at the same time, a high K insulator Ki, labelled 5, into the upper region of the electrode gap, and a contiguous low K insulator K2, labelled 6, into the lower region, both dielectrics having a high electrical breakdown strength, the vertical symmetry is again broken. Thus, a resultant upward propulsion force, dependant on the difference in dielectric constants is re-established. The continuous electrodes and dielectric together virtually eliminate stray fields and corona. The upward propulsion force for this cylindrical thruster element is then: Ftotal = 1Jc2L L V2 * (d -a) [ln(dla)]2 ad It may be shown straightforwardly that the optimum radius ratio for maximum thrust for cylindrical electrodes is d=2a.

This full cylinder combination may be regarded as an alternative building block, which is then combined in layers in the First Embodiment of the invention, as shown in cross-section in Fig. 4. Evidently, the same voltage polarity is used throughout and the thrust is upward when the high K dielectric Ki, labelled 5, is uppermost, as shown.

Fig. 5 shows another way to break the vertical symmetry in a Second Embodiment of the invention, by joining semi-cylindrical sectors in alternate directions, to produce corrugated sheets. Again, the thrust is upward when the high K dielectric Ki, labelled 5, is uppermost, as shown. In this embodiment the optimum ratio of d=2a has also been illustrated, which finite element analysis calculations confirm gives a good approximation to the equipotential distribution (and ideal E-field ratio of 2) for full cylinders. Alternate pairs of electrodes have their voltage polarity reversed so that successive pairs may be in contact and an even number of capacitor layers would probably be chosen to maintain the outer electrodes at ground potential.

Other reasonably compact arrangements are no doubt possible, but the arrangement of full cylinders seems one of the best and if ultimate space saving is needed, could be stacked in close packed hexagonal arrangements.

In summary, the invention consists of a reaction-less thrust engine, which conforms to standard EM theory and is propelled solely by the combination of divergently shaped electric fields, assisted by choice of dielectrics. The remarkable fact that this force can be non-zero and thus does not conform to Newton's third law, has not been generally recognized as possible, apart from the work and patent of Jean-Claude Lafforgue' in 1991, and two coupled papers by Zoltan Losonc in 2004, who eventually concluded that such a thrust element will not work. The present invention differs from that of these workers in that it has been designed as a practical compact multi-element high thrust engine.

Unlike the Lafforgue' structure it does not incorporate unnecessary elongated regions of constant E-field between the electrodes, nor does it include open edged semi-cylindrical electrodes, both of which unfortunately serve to introduce significant loss of thrust. A further limitation of the Lafforgue' design is that only a single dielectric is used and so the reverse thrust component coming from his region A', is generally comparable with the forward thrust. Partly as a result of this combination of factors, no high thrust realizations have been forthcoming.

Zoltan Losonc2 came to several conclusions. In his first paper he decided that extra theoretical terms were required to account for the inward force on the dielectric and so predicted a net inward force; he also concluded from experimental measurements that no thrust is possible from a full cylindrical element with two dielectrics, such as that shown here in Fig. 3. In his second paper3 he decided that conventional EM theory involving dielectrics must be incorrect and accordingly modified the theory in order to explain his null experimental results, thereby excluding any hope of such propulsion.

The present invention is based only on multiple cylindrical thrust elements with cross-sections substantially smaller than axial length L, and of the simple forms described above and straightforwardly capable of mounting in layers to utilize all three spatial dimensions. The first embodiment for instance may be shown capable of forces in the range of 5-6 tonnes, realizable with quite modest values of the high dielectric constant (-100) and voltages in the region of -30KV and current of-0.3mA to provide for insulator leakage (for dielectric resistivity --iO'3 �=�=cm), with elemental thrust capacitor cross-sections of 6mm, and total thruster dimension on the order of height=6cm x width=l2cm x L50cm.

Each thruster embodiment consists of a multiplicity of elements similar to the ones shown in Fig. 2 and Fig. 3, configured in a multiple layered planar configuration, making efficient use of all three spatial dimensions. It is also designed to minimize corona and extraneous fields outside electrode gaps by reducing sharp edges and corners to a minimum. In the case of corrugated structures it is especially important to keep gap sizes small compared with overall lateral dimensions to minimize stray fields: also to embed all electrodes in high electric breakdown strength insulating media with minimal volume and surface conductivity and leakage current. In order not to exceed electric breakdown levels, it is also important not to inadvertently create residual air or other low K gaps such as adhesive or insulating oil between the main insulating media and electrodes.

The insulating dielectric is of two types having different dielectric constants Ki and K2, but the same high breakdown voltage requirement. This enables and maximizes resultant thrust, both directly by breaking the vertical symmetry and strengthening upward thrust (say), versus downward thrust. It also maximizes resultant thrust indirectly by permitting smaller electrode gaps and element sizes. The thrust is directly proportional to the number of elements/layer and also the number of layers for the same overall size of thruster.

Therefore there is an advantage in reducing electrode gap, element size and gap voltage in correct proportions, keeping E-fields within breakdown limits. The basic limitations to this element size reduction process being the increasing complexity of manufacturing thruster elements on a small scale and increased leakage current, due to the number of elements in parallel.

The invention can be built into any vehicle for land, over or under water, air, or space transport. It has no moving parts, produces no noise and does not require any propellant to be ejected and thus is environmentally friendly. It also avoids many of the potential health hazards of rocket, jet or internal combustion engine propulsion. Although the direction of thrust has been described as upwards for simplicity, it is evident that for most purposes the normal orientation is more likely to point towards the front of a vehicle, with at least two simple schemes open for steering or braking the vehicle. The first alternative being to mount thrusters on powered gimbals arrangements, and the second to have separate thrusters pointing in different directions for steering and braking.

Fundamentally, the only power supply requirement is a DC or low frequency AC voltage supply which is in the range of thousands to tens of thousands of volts to provide sufficient thrust force to overcome any restraining forces acting on the vehicle, such as the Earth's gravitational force or frictional forces and to provide required vehicle acceleration (AF=ma).

What is less clear is how the extra work required for acceleration, over and beyond the low current to compensate small leakage currents of the insulating dielectric material, would be realised, via almost ideal, low leakage dielectrics. Thus one is forced to the conclusion, that even though more than sufficient force can be provided to levitate a vehicle with almost no power requirement, it's acceleration response might be reduced, or even harder to believe, that conservation of energy is violated and the thruster may be able to act as an energy generator. If the latter did prove to be the case, then there would be the enormous additional benefit that thrusters could be built into rotating machinery to provide free electrical power.

REFERENCES

1. "Isolated systems self-propelled by electrostatic forces" Jean-Claude Lafforgue, Alexandre (1991): French Patent FR265 1388 2. "Are cylindrical and spherical E-field thrusters violating Newton's 3rd law?" Zoltan Losonc, (2003) http://rimstar.org/zoltans/fullcylsph.htm 3. "The semi-charge model ofthe dipole-molecules in dielectrics" Zoltan Losonc, (2004) http://rimstar.org/zoltans/semicharge.htm

Claims (6)

1. CLAIMS1. A reaction-less thrust engine (or thruster), constructed from a plurality of concentric contiguous cylindrical high voltage ( 1 -> 50 KV) DC or low frequency AC capacitor elements, or sectors thereof, which produce divergent fields by virtue of their geometry, and by incorporating insulators with different dielectric constants in the electrode gaps, will produce maximum thrust in a desired direction and decreased thrust in unwanted directions, mounted in a layer or layers, so as to provide a compact efficient propellant-less thruster.
2. 2. A reaction-less thrust engine as claimed in Claimi, which is designed to keep sharp edges and corners of electrodes to a minimum in order to reduce extraneous fields, deleterious corona and ion streams across electrode gaps to a minimum.
3. 3. A reaction-less thrust engine as claimed in Claim 1 and Claim 2, wherein high electrical breakdown strength dielectric insulators, which may be solid or liquid as appropriate, are used both to completely fill the electrode gaps and to encapsulate the assembly, thus enabling the use of small elemental capacitor cross-sections without electrical breakdown, hence providing high thrust levels and limiting the possibility of residual stray electric fields and corona to a minimum.
4. 4. A reaction-less thrust engine as claimed in the preceding claims, wherein low (volume and surface) electrical conductivity dielectric insulators are used both in the electrode gaps and to encapsulate the assembly in order to keep total electrical leakage current to a minimum and thereby consume as little power as possible.
5. 5. A reaction-less thrust engine substantially as described herein, with reference to Figures 1-5 of the accompanying drawings.
6. 6. A reaction-less thrust engine as claimed in the preceding claims, wherein a multiplicity of said thrusters could be built into dynamos which might just possibly serve as free electrical power generators.