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High efficiency Lifter based on the Biefeld-Brown effect Moshe Einat and Roy Kalderon Citation: AIP Advances 4, 077120 (2014); doi: 10.1063/1.4890353 View online: http://dx.doi.org/10.1063/1.4890353 View Table of Contents: http://scitation.aip.org/content/aip/journal/adva/4/7?ver=pdfcov Published by the AIP Publishing Articles you may be interested in Transverse end effect for a hi
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  High efficiency Lifter based on the Biefeld-Brown effect Moshe Einat and Roy Kalderon  Citation: AIP Advances 4 , 077120 (2014); doi: 10.1063/1.4890353   View online: http://dx.doi.org/10.1063/1.4890353   View Table of Contents: http://scitation.aip.org/content/aip/journal/adva/4/7?ver=pdfcov   Published by the AIP Publishing   Articles you may be interested in   Transverse end effect for a high temperature superconductor electrodynamic levitation device J. Appl. Phys. 115 , 17E701 (2014); 10.1063/1.4852058 Effect of the charge surface distribution on the flow field induced by a dielectric barrier discharge actuator J. Appl. Phys. 114 , 073303 (2013); 10.1063/1.4817378 Shape oscillations of an electrically charged diamagnetically levitated droplet Appl. Phys. Lett. 100 , 114106 (2012); 10.1063/1.3694055 The Biefeld Brown Effect and the Global Electric Circuit AIP Conf. Proc. 746 , 1249 (2005); 10.1063/1.1867252 Saturation effects in dynamic electrowetting Appl. Phys. Lett. 86 , 054104 (2005); 10.1063/1.1861501 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported license. See: http://creativecommons.org/licenses/by/3.0/ Downloaded to IP: 62.219.54.250 On: Mon, 14 Jul 2014 14:19:32  AIP ADVANCES  4 , 077120 (2014) High efficiency Lifter based on the Biefeld-Brown effect Moshe Einat and Roy Kalderon Faculty of Engineering, Ariel University, Ariel, Israel (Received 21 April 2014; accepted 3 July 2014; published online 14 July 2014) The Biefeld-Brown is a fascinating effect with which levitation can be reachedwithout moving or rotating elements. Static voltage is applied between asymmetricelectrodes and a force towards the small electrode is generated. This effect is studiedexperimentallyinthispaper.Usingthiseffectasetofexperimentsisconductedtryingto clarify the relation of the model geometry to the induced force. The results showclear relations of the generated force to the model structure and dimensions. As theasymmetry is stronger, the force is stronger. According to the experimental results, aset of preferred parameters is given to strength the effect. Choosing the geometricalproperties properly led to improvement of factor  ∼ 9 in the generated force andefficiency. Nevertheless, some results provides contradictions to earlier models of electrohydrodynamicmic(EHD)describingtheeffectandrevealunresolvedquestionsregarding this effect.  C   2014 Author(s). All article content, except where otherwisenoted, is licensed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4890353] I. INTRODUCTION Although the Biefeld-Brown effect was discovered over 80 years ago, 1 only limited numberof publications were published in the scientific literature describing it. This effect occurs when adevicewithtwoasymmetricelectrodesisconnected toafewkVvoltage.Aforceisobtainedpushingthe device towards the small electrode, regardless of the voltage polarity. Levitation can easily beobtainedwithoutanymovingparts.Thescientificattentiondrownedtoexplainthisfascinatingeffectwasverylittleformanyyears.Butunlikeothereffects,buildingasetupdemonstratingthiseffectcanbe done by rather simple means. Therefore, at the recent years many amateurs built a ‘home-made’setup and uploaded a ‘youtube’ movie demonstrating the effect with the nickname ‘Lifter’. Most of the physicists and engineers seeing these movies are first fascinated by it, and then categories it assome kind of either photomontage or magician trick. But with some patient, after watching many of these movies, one’s healthy curiosity must rise. They can’t all be fraud. So we have decided to check it out in laboratory conditions and perform a controlled experiment. First, a levitating model wasbuilt imitating models seen in the movies. After few failure models, indeed the fascinating effectof levitation without any moving parts was obtained in the lab. 2 Two asymmetric electrodes fixedon balsa wood sticks, connected to a voltage power supply were levitating in a stable manner asdescribed in details below.Scientific literature exploration showed that the theory describing this effect is still immature.Early ideas suggested different explanations of unknown physics, but recent works rejected theseideasanddescribedtheforceasanoutcomeresultofionwind, 3–8 anelectrohydrodynamicmic(EHD)effect. Few experiments were carried out to support these theories and fair agreement between thetheoreticalpredictionandtheexperimentswasreportedforthedescribedsetup.NASAhasshown aninterest in this effect in several reports, and in Ref. 9 from 2004 it is stated that “there is surprisinglylittle experimental or theoretical data explaining this effect.” Another recent comprehensive work was done in NASA 10 at 2009, in order to examine whether this effect could be scaled to values of interest for aircraft propulsion.In this experimental study, parametric measurements were done trying to relate the generateddriving force of the Biefeld-Brown effect to the structure of the model. Such experimental results 2158-3226/2014/4(7)/077120/20  C  Author(s) 2014 4 , 077120-1  All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported license. See: http://creativecommons.org/licenses/by/3.0/ Downloaded to IP: 62.219.54.250 On: Mon, 14 Jul 2014 14:19:32  077120-2 M. Einat and R. Kalderon AIP Advances  4 , 077120 (2014) FIG. 1. The ‘lifter’ arrangement. A General schematic (a), and a picture of the experimental device (b).TABLE I. The parameters of the lifter.Lifter parameter ValueAluminum foil width 2 cm.Triangle side length 21 cm.Distance between the Copper wire and the aluminum foil 3 cm.Copper wire diameter 0.133 mmAluminum foil thickness 0.03 mm.total model weight 1.72 g may help understanding the nature of the force, and even reveal ways to maximize the effect. Indeed,such relations between the model structure and the generated driving force were experimentallyfound as described further on. Also, some contradictions to the earlier suggested EHD models arefound experimentally. II. PRELIMINARY EXPERIMENT – DEMONSTRATING A LEVITATING MODEL WITHOUTMOVING PARTS In order to demonstrate the levitation effect a model was built from balsa wood, aluminum foiland copper wire as seen in Fig. 1. The parameters of the model are in Table I. A high voltage power supply with changeable polarity and digital readings of the voltage andcurrent (Spellman SL1200) was connected to the model as seen in Fig. 1(a). The connection of the power supply was done in four different ways (Table II):  All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported license. See: http://creativecommons.org/licenses/by/3.0/ Downloaded to IP: 62.219.54.250 On: Mon, 14 Jul 2014 14:19:32  077120-3 M. Einat and R. Kalderon AIP Advances  4 , 077120 (2014) TABLE II. Circuit configurations. (1) (2)  (3) (4) V(kV) P(W) V(kV) P(W) V(kV) P(W) V(kV) P(W)Takeoff 16.65 2.83 –17.64 3.18 20.19 6.66 –17.89 5.01Minimum neededfor levitation16.19 2.42 –17.41 2.96 18.72 4.31 –17.37 4.17 1) Thecopperwirewasconnectedtoa positive highvoltageandthealuminumfoilwasconnectedto the  ground .2) Thecopperwirewasconnectedtoa negative highvoltageandthealuminumfoilwasconnectedto the  ground .3) The copper wire connected to the  ground  and the aluminum foil was connected to a  positive high voltage.4) The copper wire connected to the  ground  and the aluminum foil was connected to a  negative high voltage.The results were interesting. One could think that if a certain polarity will lift the model, theopposite polarity will push it down. The results showed different. Both polarities caused forceupwards. This result reinforce results in a report made in NASA, 9 although it is mentioned in thisreference that in certain conditions the forced direction was reversed. We did not see reversal of theforce as will be detailed in the following experiments. Also, for the same polarity the location of theground was important. When the ground was connected to the foil (for both polarities) the levitationwas obtained in much lower power and voltage.In every configuration the minimal voltage and power needed for ‘takeoff’ of the lifter,and the minimal voltage and power to keep the levitation were measured. The experimental re-sults are given in Table II. The minimal flight and levitation voltage and power were obtained when the copper wire was connected to a positive voltage and the aluminum foil was grounded(connection # 1).Already at the end of this experiment a clear observation is made: this device creates a winddownwards (in all four connections). It is easily felt and seen. To demonstrate it small objects wereplaced in the device vicinity and the generated wind blow them away. Also a smell is noticed thatcan be related to ionization. Experienced experimentalist indicated that it is the smell of Ozone, butit was not further checked. III. PARAMETRIC EXPERIMENTS Althoughthelevitationconfigurationisfascinating,itisnotconvenientfortheexplorationoftheeffect. Aside from the minimal voltage for takeoff and minimal voltage for maintaining levitation,recording continuous data as a function of the voltage increment is difficult. Therefore, a modelwith reversed configuration was built. In this model the small electrode was placed in the bottomand the large electrode was placed above. As a result, the force in this model operates downwards.We named it ‘Pressing model’. The model was placed on a digital scale and measurements of the weight were continually taken for varying voltage. Several experiments were done with the‘Pressing model,’ trying to identify the relation between the device structure and the obtainedweight. First, the influence of the electrodes gap was checked for various dimensions of the smallelectrode, and then systematic modification of the structurewas done by adding elements. Followingis the experiments description followed by the results. General dimensions of the models are inTable III.  All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported license. See: http://creativecommons.org/licenses/by/3.0/ Downloaded to IP: 62.219.54.250 On: Mon, 14 Jul 2014 14:19:32
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