JPH01222289A - Method and device for visualizing mhd effect - Google Patents

Abstract

PURPOSE:To visualize an MHD (Magnet-Hydro-Dynamic) effect by allowing an electric current to flow under the condition that a magnetic field words, decomposing water and allowing bubbles of hydrogen and oxygen to ascend. CONSTITUTION:An electrolytic water solution 2 of NaOH, etc. is put into a transparent case 1, and two pieces of electrodes 3, 4 are opposed to each other in the vertical direction. When a voltage is applied to the electrodes 3, 4 and a current is allowed to flow, oxygen or hydrogen is generated in accordance with whether the polarity of the electrode is positive or negative, and it becomes a thin line and ascends. When a magnetic field is applied thereto, the line is inclined. That is, the solution can be made simply since it will suffice that a small quantity of electrolyte of NaOH, etc. is added to water, and also, because of an electrolysis, as for a power source, a small battery is enough. In such a way, by using a simple method and device, an MHD effect (or Lorentz's force) can be visualized.

Description

[Detailed Description of the Invention] [Objective] This invention generates MHD (Magnetic HD) by passing an electric current under the action of a magnetic field to decompose water and raise hydrogen and oxygen bubbles.
-Hydr6-Dynamic) An educational experimental method and device that makes the effect visually visible.

Bimitate Nira I One of the basic laws of electronic 8i% science is Fleming's left hand rule. This means that when you place your left hand's index finger in the direction of the magnetic field and your middle finger in the direction of the current, a force acts perpendicular to them in the direction of the thumb, and this force is called the Lorentz force. One application of this is electromagnetic propulsion ships. This means that if the magnetic field is placed so that it is directed toward the ocean floor, and a current is passed at right angles (that is, parallel to the sea surface), the ship will exert a backward force on the seawater, and the reaction will cause the ship to move forward. I will do it. This is also called the MHD (magnetohydrodynamic) effect. With the recent advent of superconducting technology, extremely strong magnetic fields have become available, and ocean engineering technology is entering a new era.

Innie n7 In this way, the MHD effect is becoming important from an applied perspective, and is also important for helping students learn the basics of electromagnetism. However, until now, there has been no educational experimental method or device that makes the MHD effect visually visible. Therefore, the present invention aims to provide a method and apparatus that visualize the MHD effect.

[Composition] Mouth *7. ．． F FIG. 1 is a diagram illustrating the MHD effect method and apparatus of the present invention. Figure 1(a) shows N a inside the transparent case 1.
Add an electrolyte aqueous solution 2 such as OIf, and connect two electrodes 3.
4 are vertically opposed to each other. When a voltage is applied to the electrode 3.4 and a current is passed, oxygen or hydrogen is generated depending on the polarity of the electrode, and rises in the form of a thin line. When a magnetic field is applied to this as shown in Figure 1(b), the streaks appear. This makes it possible to visually see the MHD effect.

FIG. 3 and FIG. 4 are explanatory diagrams of a first embodiment and a second embodiment of the present invention, respectively. A method of applying a magnetic field as in these areas may be by using a permanent magnet or an electromagnet. Unlike the permanent magnet shown in Fig. 3, Fig. 4 is convenient in that the direction of the magnetic field can be easily changed by reversing E2 and the current flows in the opposite direction, and the strength of the magnetic field can be changed freely. Fifth
This figure and FIG. 6 are perspective views of a third embodiment of the present invention. 2
The wooden electrodes are arranged parallel to each other and facing upward on the bottom of the transparent case. In this way, vertically rising bubble lines are generated in parallel from each electrode when no magnetic field is present. When a magnetic field is applied, the two filaments are biased in opposite directions as shown in the figure.

January The electrolytic current of an electrolyte solution is dependent on mass transfer.

Methods of mass transfer include (1) convection, (2) electrophoresis, and (3)
) There are three types of diffusion terms. Diffusion occurs in the immediate vicinity of the electrodes. The potential difference between the electrodes causes electrophoresis, and the electric current caused by this electrophoresis flows from one electrode to the other.

On the other hand, the upward flow of a filament made up of a collection of microscopic bubbles generated from a thin electrode by electrolysis generates a convection current accompanying the flow. Let q be the electric charge of the ions in the electrolyte, V be the moving speed, and B be the magnetic flux density, then the force acting on the ions is F.
(Lorentz force) is F = q v X B
(1). Therefore, in Figure 1 (a), the negative charge is moving with the filament from the bottom to the top at a constant speed, so when a magnetic field B is applied to it, a force F acts in the direction of the filament, as shown in Figure 2. changes to the direction of V' and moves to the left by θ°.Therefore, in Fig. 1(b), the filament is pushed to the left as shown in the figure.Also, in Fig. 5(a), the two filaments are pushed to the left. Since the flow of the filaments is a flow of charge with different polarity, positive and negative, the two filaments move in opposite directions according to equation (1). Become.

Actual measurement results using the apparatus shown in FIG. 4 are shown in FIG.

The magnetic field was generated by an air-core coil with a decomposition voltage of 4.8 V and a decomposition current of 400 mA, and the measurement results were obtained in the range of 0 to 550 Gauss. In Figure 6, the vertical axis is the deflection angle of the filament (θ
), and the horizontal axis is the magnetic flux density B.

[Effects] The MHD experimental method and apparatus of the present invention have the following effects.

The (+) solution can be easily made by adding a small amount of an electrolyte such as NaOH to water. Also, because of electrolysis, a small battery is sufficient as a power source. By using such a simple method and device, the MHD effect (or Lorentz force) can be visualized.

Therefore, it has a great educational effect in stimulating students' curiosity and aiding their understanding.

(2) Since the electrodes are thin, the generated gas does not form large bubbles, but has the effect of forming very fine-grained, fine-grained bubbles. Therefore, it has the effect of being easy to see with thread-like striations.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are diagrams showing the principle of the present invention, Figure 2 is an explanatory diagram applying Lorentz's law to ion stream lines,
Fig. 3 is a perspective view showing the first embodiment of the present invention, Fig. 4 is a front view showing the second embodiment of the invention, Fig. 5 (aXb) is a view showing the third embodiment of the invention, and Fig. 6 4 is a diagram showing experimental data obtained by the method shown in FIG. 4. FIG. DESCRIPTION OF SYMBOLS 1...Transparent container, 2...Electrolyte solution, 3...Electrode, 4...Electrode, 5, 6...Striae formed by fine bubbles, 7
...Permanent magnet, 8...Coil, 9.10...Electrode. Patent applicant Takashi Aoki Two idiots Figure 2 y' v 3rd
Figure 27 Figure 4 Figure 6 Magnetism! ! Density B (Gauss)

Claims (2)

[Claims] (1) A MHD effect visualization method having a structure in which a magnetic field is applied between electrodes in water electrolysis. (2) An MHD effect visualization device having a structure that applies a magnetic field between electrodes in water electrolysis.