"Solar mill" engine.

Dehelean, Nicolae ; Lovasz, Erwin-Christian

1. INTRODUCTION

The idea of the paper is to value some ancient ideas related to the old human dream "perpetuum mobile". It is well known that all the mechanisms that produce movement are actually machines; a lot of them are thermal machines. These are in the field of interest of the paper.

Definition: "A perpetual motion machine (PMM) is a device based on mechanical, chemical, electrical or other physical processes which, when started, will remain in operation forever and provide additional work as well. Only the natural wear of the components will eventually stop its operation."

A well known schema (Wikipedia, 2009) from the class perpetual motion machine of the first kind (it produces energy from nothing) is the "Overbalanced Wheel" (figure 1). It was thought that the metal balls on the right side would turn the wheel because of the longer lever arm, but since the left side had more balls than the right side, the torque was balanced and the perpetual movement could not be achieved (hpgramatke.net/ perpetuum/index.htm, 2009).

[FIGURE 1 OMITTED]

This one could be transformed into a machine if it places the wheel between a hot thermal source [S.sub.H] and a cold thermal source SC. The wheel should take [Q.sub.1] from [S.sub.H] and should give [Q.sub.2] to [S.sub.C], [Q.sub.1] > [Q.sub.2]. It will result a mechanical work (Halliday, D & Resnick, R 1975) L, expressed in (1).

L = [Q.sub.1]-[Q.sub.2] (1)

2. DESIGN STRATEGY

First it needs to replace the arms with balls by a kind of heat sensible arms. A pair of arms 1 consists of a close-fitting pipe. The pipe is attached to a hub 4 which allows for spinning motion Inside of the pipe it is placed a free piston 3 and the same amount of working gas mass into the two cavities 2. Therefore the piston stays in the median position (Fig. 2) and the wheel is not a machine.

If it split the space in two hemispheres and it places into them the two thermal sources, as it is shown in Fig. 3, the two cavities will get two different temperatures [T.sub.2] and [T.sub.3] (Leca & Pop, 1987) [T.sub.2] > [T.sub.3].

The maximal torque [T.sub.max] for a single arm pair is given by equation (2):

[T.sub.max] = m x g x a (2)

m--piston mass

g--gravitation acceleration

a--eccentricity

Using the ideal gas law, it results:

[FIGURE 2 OMITTED]

[FIGURE 3 OMITTED]

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (3)

To obtain a useful relation of the torque it needs to write the geometrical relation in the pipe, equation system (4) (Shodor, 2009).

[MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (4)

The last equation in (4) system comes from (3) system. Solving the (4) system results successively l2 (5), a (6) and the maximal torque (7).

[l.sub.2] = [T.sub.2](l-[l.sub.p])/[T.sub.2] + [T.sub.3] (5)

a = [T.sub.2] (l-[l.sub.p])/[T.sub.2] + [T.sub.3] + [l.sub.p] - 1/2 (6)

[T.sub.max] = mg [[T.sub.2](l-[l.sub.p])/ [T.sub.2] - [T.sub.3] - l-[l.sub.p]/2 (7)

To enlarge the torque [T.sub.max] it is necessary:

1. to increase m, [T.sub.2] and l;

2. in the same time to decrease [T.sub.3] and [l.sub.p].

3. THE SELF-START ENGINE

The engine in figure 3 has the disadvantage of the thermal engines, they don't start alone. This engine could exceed this inconvenience using at least three pairs of arms (figure 4). The arms present an angular divergence of 60[degrees]. Therefore the engine has no dead point and works like a three phase electric motor. It becomes self-starting.

Another great disadvantage is the way of heat transportation to the mill arms. The angular position of the heat injection is very precise. A good solution to this requirement it is shown in figure 5. A set of wings 1 with a special shape are placed tightly on the tubular arms 3. Under the mill there are placed a tank with hot water 2. The wings are immersed cyclically in hot water and transmit the heat from the water to the working gas in the pipe. When the wings pass from air, they transfer the residual heat from the working gas to the atmosphere. Thus the solar energy could be easily acquired by a classical solar panel and used to heat the water in the tank 2. This solution has another huge advantage: the water tank has a great thermal inertia that improves the constancy of the wheel movement.

4. FUTURE RESEARCH

The research in this paper will lead to a new family of thermal engines, able to convert thermal energy into mechanical energy, using a pair of thermal sources with low temperature gradient. This engine family will be adequate to use both solar and geothermal energy.

[FIGURE 4 OMITTED]

[FIGURE 5 OMITTED]

5. CONCLUSION

The science basic laws knowledge makes humans able to solve ancient mistakes and to create new devices to their own benefit. Any schema of a "perpetual motion machine" could be transformed into a real machine using the principles and the laws of science. This developing way recuperates ancient ideas in a modern fashion in order to create new conversion energy devices. If the working principle of a PMM is well hidden the device could be presented as a "miracle" by a magician in a public show.

6. REFERENCES

Halliday, D & Resnick, R (1975). Pysics, Editura Didactica si Pedagogica Bucuresti

Leca, A. & Pop, M. (1987). Indrumar; tabele, nomograme si formule termotehnice (Guide-book; Tables, nomograms and thermodynamics formulae), Ed. Tehnica, Bucuresti

*** (2009) http://en.wikipedia.org/wiki/File:Perpetuum1.png Accessed: 2009-07-13

*** (2009) http://www.hp-gramatke.net/perpetuum/index.htm Accessed: 2009-07-09

*** (2009)http://www.shodor.org/UNChem/advanced/gas/ index.html Accessed: 2009-07-09