Abstract we nave Carlen out an experimental Ana ethnocentric study o phenomenon was first reported in 2009. Qua mum motors. I Nils Two papers have been published on Iraqi. Com, the first describing the phenomenon (Shirtless et al), the second offering a theoretical model for the observations (Am]aid et al). The papers differ in their explanations. Shirtless claims that rotation is caused by a surface effect but gives no clear mechanism as to how this could arise.
Shirtless sakes use of edge effects arising from Reynolds Stresses and Taylor Arise dispersion. On the basis of our investigations we present a new theory which we have called Spinet theory. This is a development of experiential observations of micro-vortex formation by Zachary Grandchild and colleagues at G¶debugger University and Chalmers University. We believe the effect to be a surface effect, enhanced by the concentration of surface charge. We believe edge effects are important as they provide a structure for the initiation of the flow.
We have attempted to link our Spinet theory with our observations and those of Shirtless et al. We have made and tested a novel prediction that our theory suggested. We believe this effect is not predicted by the other authors’ work. Introduction In BIBB, a group AT Iranian pentacle’s made an Interesting Alcove’s. I nee placed a thin film of water in a small cell and bathed it in two perpendicular electric fields. To their amazement the liquid film began to rotate and for this reason they named it the “liquid film motor”.
The question that was raised however was: “What causes the liquid film to rotate? ” The Iranians who discovered the phenomenon published a paper with their own explanation and results: CONCLUSIONS (made by the Shari University of Technology, Department of Physics) “Our experimental observations have shown that the suspended films of some liquids can rotate by applying pure electric fields. In contrast with the convective vortices in suspended films, speed and direction of the rotation in the case of our film motor is fully under control by the mean values of the crossed electric fields.
In our experiments the films with length scales from tenth of millimeter up to several centimeters have been examined, and there is no reason that it does not work in smaller length scales. This phenomenon may have wide industrial application, e. G. In liquid based centrifuge or liquid mixing devices. Liquid films rotate without any electro-chemical reactions near the electrodes. Dissolving some amount of a salt in a pure liquid, although increases the electrical conductivity by a few orders of magnitude, but has not a notable effect on the rotation velocity and threshold.
Therefore, the ion movement does not have a significant effect in the rotation, in contrast to the role of the intrinsic dipole moment of liquid molecules which is deeply vital. Examining different liquids shows that polar squids rotate well. Investigating angular velocity of vortex shows it rotates faster in the center. Any efforts to rotate a bulk of liquid was defeated. The fact that only thin liquid films rotate notably and that rotation can not be observed in relatively thick films even at high fields, implies that this phenomenon is a surface effect. A second paper was published by the Department of Mathematics, Mechanics and Computer Science, Southern Federal University, 344090, Roster-on-Don, Russia In this paper they state: “The rotating motion of a fluid as a whole caused by the action of a constant electrical lied is so unusual that the authors call this effect a liquid film motor, emphasizing that it represents a new type of engine. They denied the possibility of the generating AT sun a now Day ten gage erects.
In contrast, we snow Tanat ten Jump AT an electric field across a water-dielectric interface produces the tangential velocity of a liquid that can maintain a steady rotating flow in the whole film. In other words, we demonstrate that one does not need to use a heuristic idea about the switching of the molecular orientations: this phenomenon can be explained with the use of classical tools only. In our model the rotating motion in a film is explained by the electro-kinetic effects at its edges. According to our theory the ratio between the spatial scales of a flow domain plays a crucial role.
Only for thin films the classical edge effects can generate the rotation; in contrast in the flow domains with all spatial scales of the same order this effect will be absent. ” The papers contradict each other and disagree on the reasons why the liquid film rotates. One argues that the phenomenon is caused by an edge effect while the other insists that the fluid moves fastest in the center. And so the question remains: “Why does the liquid film rotate? ” We aim to explain this puzzling phenomenon. Liquid Film Solution To find a good quality liquid film we decided to do research on the internet.
We had discovered that the film should work with pure water however we found it difficult to produce films of pure water and so we come to a decision to use a dilute bubble mixture. We discovered an American brand of detergents called Joy. In our experiments we used a dilute solution of Joy, sometimes on its own, sometimes with glycerol and sometimes with sugar. We discovered that a very dilute solution of Joy with a small drop of glycerol was the most successful. Apparatus To make the film rotate we used two power supplies; one of which reaches VIVA and the other V.
We found these in an old storeroom in the Physics department. They had been donated by the local University years before when their Physics department closed down. [pick] The cells were made from printed circuit board in the Technology department. We made a number of cells in the course of the investigation some of which are pictured below: Experimental Methods Our first objective was to find a way to make the liquid film rotate. We constructed the following apparatus: This was our first attempt at creating a device which would spin the liquid film.
Initially, this model worked fairly well and we could see the liquid film spinning although it was not always clear. There were problems such as sparking at the ends of the copper strips where moisture was shorting the plates of the capacitor and small fires were often created. The sparking caused us to redesign the carrier in such a way that the water would be unable to short the circuit. Moment AT Recording Helm Rotation We spent a long time developing a reliable way of producing and rotating films. This involved a lot of experimentation and a little luck.
In order to see the rotation we tried using natural light, a flash lamp, some Leeds from Technology, dark rooms and bright rooms and different colors of paper under the apparatus. Eventually we hit upon a light box which when angled allowed us to see the film’s rotation clearly. Imaging the rotation clearly was a big problem. We began by using an Intel plug and play microscope found in the Technology department. We progressed to using a died camera which Zoe was able to obtain after much pleading. To make the soap film we went through a number of stages.
We began by immersing the printed circuit board in the soap solution and slowly withdrawing it, unfortunately this left the board very wet and prone to shorting out the capacitor. Eventually we discovered that dipping a finger in the solution and drawing it slowly across the cell was an effective way of producing the film. This meant that the minimum amount of solution was present on the rest of the circuit board. Experimental Observations Carrying consistent experiments was extremely difficult. On occasions the liquid film would spin immediately and quickly, other times it would spin slowly and more often than not it refused to spin at all.
We did however manage to obtain some videos in which the film rotated satisfactorily. We observed that the speed at which the film rotated varied when the voltage was altered and again when the electrolysis current was changed. With this in mind we carried out an experiment to discover the minimum voltage and electrolysis current required to spin the film. We set the voltages at a number of values and measured the electrolysis current at which rotation ended. As we needed to use the same film it was only possible to obtain four results after a number of tries.