On the electric charge collected by water-drops falling through a cloud of electrically charged particles in a vertical electric field

1935 ◽  
Vol 151 (874) ◽  
pp. 665-684 ◽  
Keyword(s):  
Electric Field ◽  
Electric Charge ◽  
Negative Charge ◽  
X Rays ◽  
Vertical Electric Field ◽  
Water Drops ◽  
Cloud Particles ◽  
Large Water ◽  
Electrically Charged ◽  
Positively Charged

The experiments described in this paper are a continuation of work described in a former paper, and have for their object the examination of a mechanism suggested by Wilson in connection with the theory of thunder-clouds. In the former work the interaction of large water-drops with ions produced by X-rays was investigated. In the present work the interaction of large water-drops with electrically charged cloud particles is investigated, and the mechanism suggested by Wilson takes the following form. Consider an uncharged water-drop falling vertically through a cloud of very small water-droplets, each of which has an electric charge either positive or negative. Let there be a vertical electric field which will be taken to be of positive potential gradient so that positively charged cloud particles move down and negatively charged cloud particles move up. The electric field induces equal charges of opposite signs on the upper and lower halves of the drop. In the case considered the upper charge is negative and the lower one positive. A charged cloud particle has a definite small mobility depending on its radius and the charge it carries. Suppose now that the mobility is so small that in strong electric fields, such as occur in thunder-clouds (up to 10,000 volts/cm), the velocity with which the positively charged cloud particles move down is less than the velocity of the falling drop. Under these conditions, those positive cloud particles which are above the drop cannot overtake the drop and so do not reach it, although attracted by the negative charge on its upper half. Those positive cloud particles, which are below and which the drop over-takes, are first repelled by the lower positive charge on the drop before being attracted by the upper negative charge and, since these charges are equal in the neutral drop, these cloud particles do not reach it. Negative cloud particles coming up to meet the falling drop are attracted to its lower positively charged half and give the drop a net negative charge. This destroys the equality of the induced charges, and some of the positive cloud particles which the drop overtakes are now attracted to it. In the presence of equal numbers of positively and negatively charged cloud particles a limiting condition is approached in which the drop collects equal numbers of positive and negative cloud particles per second and has a net negative charge equal to some fraction of the induced charge.

Movements of electrically charged cloud particles

1936 ◽  
Vol 32 (3) ◽  
pp. 486-492 ◽  
Author(s):  
J. P. Gott
Keyword(s):  
Electric Field ◽  
Air Stream ◽  
Vertical Electric Field ◽  
Rain Drop ◽  
Cloud Particles ◽  
Electrically Charged

Experiments are described in which observations were made of the motion of electrically charged cloud particles past a sphere. The cloud particles were moving vertically up in an air stream, and there was a vertical electric field. This gave conditions similar to those surrounding a falling rain drop in a thundercloud, and the observations are in accordance with the theory proposed by Wilson to account for the mechanism of thunderclouds.

Radial component of vortex electric field force

2021 ◽  
Vol 11 (1) ◽  
pp. 32-35
Author(s):  
Vasyl Tchaban ◽  
Keyword(s):  
Electric Field ◽  
Equations Of Motion ◽  
Spherical Body ◽  
Radial Component ◽  
Force Interaction ◽  
Finite Speed ◽  
The Third ◽  
Electric Field Force ◽  
Electrically Charged ◽  
Positively Charged

he differential equations of motion of electrically charged bodies in an uneven vortex electric field at all possible range of velocities are obtained in the article. In the force interaction, in addition to the two components – the Coulomb and Lorentz forces – the third component of a hitherto unknown force is involved. This component turned out to play a crucial role in the dynamics of movement. The equations are written in the usual 3D Euclidean space and physical time.This takes into account the finite speed of electric field propagation and the law of electric charge conservation. On this basis, the trajectory of the electron in an uneven electric field generated by a positively charged spherical body is simulated. The equations of motion are written in vector and coordinate forms. A physical interpretation of the obtained mathematical results is given. Examples of simulations are given.

scholarly journals The relation of spermatozoa to certain electrolytes.—II

1920 ◽  
Vol 91 (637) ◽  
pp. 147-157 ◽  
Keyword(s):  
Electric Field ◽  
Alkaline Solution ◽  
Negative Charge ◽  
Potential Gradient ◽  
Theoretical Aspect ◽  
Normal Activity ◽  
Acid Solutions ◽  
Present Communication ◽  
Two Phases ◽  
Positively Charged

The fact that living spermatozoa move towards the positive pole of an electric field has been known for some years. In a note published in 1915, the writer (8) pointed out that this movement is dependent upon a certain concentration of hydroxyl ions, without which the spermatozoa neither exhibit their normal activity nor do they move in an electric field. In the same paper the behaviour of spermatozoa to such trivalent ions as cerium was briefly described. In the present communication these results are enlarged, and the problem briefly discussed from its theoretical aspect. A considerable mass of evidence now exists to show that the surface charge of a particle or membrane is profoundly affected by the nature of the solution with which it is in contact. Albumen particles, when suspended in an acid medium, are positively charged; when in an alkaline medium they are negatively charged. Perrin (11) has shown that, if a diaphragm separates two phases between which a potential gradient exists, then the gradient can increase or decrease by treating the diaphragm with various agents. In acid solutions a negative diaphragm becomes less negative, and finally positive; in an alkaline solution the negative charge is increased.

scholarly journals The mechanism of a thunderstorm

1927 ◽  
Vol 114 (768) ◽  
pp. 376-401 ◽  
Keyword(s):  
Negative Charge ◽  
Positive Charge ◽  
Negative Polarity ◽  
Meteorological Conditions ◽  
General Consideration ◽  
Positive Type ◽  
Electrical Fields ◽  
Lightning Discharges ◽  
Water Drops ◽  
Large Water

In 1909 I described a theory of the origin of the electricity in thunderstorms based on the observation that when a drop of water is broken up in the air the water obtains a positive charge while the corresponding negative charge is given to the air. Little attempt was then made to work out the details of the processes involved in a thunderstorm; only the most general consideration was given to the quantities involved and no description of the nature of the lightning discharges was attempted. This was mainly because very little was then known of the air currents in a thunderstorm and still less of the associated electrical fields. Recently a number of papers have been published recording the electrical fields associated with thunderstorms and the sudden changes in the field which accompany lightning discharges. The authors of these papers have expressed the opinion that their observations of changes in field-strength do not agree with what is to be expected according to the theory which I have propounded. This opinion is most strongly expressed in the paper by Schonland and Craib, where it is stated (p. 242): “Such a predominance of the positive type suggests that Simpson’s theory of the production of the charge by the breaking up of large water-drops in an ascending air current, which would produce a cloud of negative polarity, must either be rejected or radically altered.” On the other hand, the data on which these criticisms are based, together with the further knowledge of the meteorological conditions in thunderstorms which has recently been attained, provide the means of completing the details of the theory which were lacking in 1909, and it is now possible to describe the complete mechanism of a thunderstorm both qualitatively and quantitatively. This is the object of the present paper, in which I hope to be able to show that the criticisms are in error and that the theory completely explains all the observations at present available.

scholarly journals On the electric charge collected by water drops falling through ionized air in a vertical electric field

1933 ◽  
Vol 142 (846) ◽  
pp. 248-268 ◽  
Keyword(s):  
Electric Field ◽  
Electric Charge ◽  
Water Drop ◽  
Negative Ions ◽  
Selective Absorption ◽  
Net Charge ◽  
Positive Ions ◽  
Vertical Electric Field ◽  
Lower Charge ◽  
Ionized Air

In connection with the theory of thunderclouds and of the electric charge brought down by rain, Wilson has suggested* the following mechanism. Consider an uncharged water drop falling vertically through ionized air. Let there be a vertical electric field, so that ions of one sign are moving down in the same direction as the drop falls, while ions of the other sign are moving up against the drop. The electric field induces equal charges of opposite signs on the upper and lower halves of the drop. Suppose now that the electric field has such an intensity that the velocity of the descending ions is less than the velocity of the falling drop. Under these conditions those descending ions which arc above the drop, cannot overtake the drop and so do not reach it, although attracted by the charge on its upper half. Those descending ions which are below and which the drop overtakes, are first repelled by the lower charge on the drop before being attracted by the upper charge and, since these charges are equal in the neutral drop, it is to be expected that these ions will not reach it. Ions coming up to meet the drop are attracted to the lower charge and give the drop a net charge. This destroys the equality of the induced charges and some of those ions which the drop overtakes are now attracted to it. A limiting condition will be approached in which the net charge is equal to some fraction of the induced charge. This mechanism does not depend on whether the electric field is directed vertically upwards or vertically downwards and for this reason specific mention of the sign of an ion has been avoided. In a particular case, suppose the potential gradient, measured upwards, to be negative, so that positive ions move up and negative ions move down. The charges on the upper and lower halves of the falling drop will then be positive and negative respectively. If the water drop falls more rapidly than the negative ions move down, it will collect a net positive charge, by selective absorption of positive ions at its lower negatively charged surface. Since a drop of 1 mm. radius has a terminal velocity of about 6 metres per second, the electric field must not exceed 400 volts/cm. for ions of mobility 1·5 cm./sec./volt/cm.

scholarly journals Drop race: How electrostatic forces influence drop motion

2021 ◽  
Author(s):  
Xiaomei Li ◽  
Pravash Bista ◽  
Amy Stetten ◽  
Henning Bonart ◽  
Maximilian Schür ◽  
...  
Keyword(s):  
Negative Charge ◽  
Equation Of Motion ◽  
Electrostatic Forces ◽  
Tilted Surface ◽  
Novel Approach ◽  
Drop Motion ◽  
Water Drops ◽  
Inclined Planes ◽  
Low Permittivity ◽  
Positively Charged

Abstract Water drops sliding down inclined planes are an everyday phenomenon and are important in many technical applications. Previous understanding is that the motion is mainly dictated by viscous and capillary forces. Here we demonstrate that, in addition to these forces, drops on hydrophobic surfaces are affected by self-generated electrostatic forces. In a novel approach to determine forces on moving drops we imaged their trajectory when sliding down a tilted surface and apply the equation of motion. We found that drop motion on low-permittivity substrates is significantly influenced by electrostatic forces. Sliding drops deposit a negative charge on the surface, which interact with the positively charged drops. We derive an analytical model to describe the force and validate it by numerical computations. The results indicate how to describe and facilitate drop motion in applications, such as in microfluidics, water management on car surfaces, and the creation of sliding drop electrical generators.

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