Wave Propulsion: Brief History and Remedy

French and Russian proponents of harnessing sea wave energy provide a short history, identifying why the approach has been abandoned by major entities, and suggesting how to revive this yet-to-be-fully-actualized approach.

by Dr. E.Sorokodum and Francois Kneiders
Edited by: Mary-Sue Haliburton and Sterling D. Allan

Pure Energy Systems News - Exclusive

The Orcelle ship concept includes wave energy conversion and fin propulsion as part of its multi-faceted sustainable energy power design.

The increased cost of power resources and shortage of fuel result in a need to develop new ways to get more effective use of energy sources. One little-known way is to use energy of sea waves with the help of oscillating wings to propel ships.

N.E.Zhukovsky's 1892 article shows that selection of energy from certain types of atmospheric vortices and waves, similar to those which enable flight of birds, is possible with motionless wings [9]. In this little-known and ignored work is the key to understanding many phenomena: extraction of energy from sea excitements and creation of driving force (thruster); a decrease of aero-hydrodynamical drag with the help of wave character of flow (Zhukovsky –Knoller-Betz effect); an explanation of Grey’s paradox about economical swimming of dolphins and sea animals. For an explanation of the physics behind these phenomena please see the website www.vortexosc.com.

G.E.Pavlenko's 1936 article outlines the major scientific work on using the energy of rocking on heavy sea for movement of ships [11]. The researchers worked on a theoretical basis for creation of draft (thrust) by applying the energy of sea waves to underwater wing structures on a ship. Please see references 1,7,8,10,14. Tests of model thruster-wings using energy of waves began in 1978. In 1980, in Trondheim, Norway, an experiment was run on a model boat 1.02 m. in length, in which a traveling speed of 1.76 knots was fixed [6]. The engine had been switched off so that movement was occurring only due to sea-wave energy. Norway's Wave Control Company carried out natural tests on a 7.5 m boat (fig.1) which was equipped with two and four wings, each having a surface area of 0.5 square meters. The maximal speed achieved was 6 knots.

Fig.1. Boat with thruster. Two wings are mounted below bow of boat, one on either side, to take advantage of sea waves’ energy.

Fig.2 Thruster extracting energy of waves: the wing changes angle of attack with the help of springs.

Fig.3 Thruster receiving energy of waves: the wing changes angle of attack with the help of pneumatic or hydraulic cylinders.

Application of these mechanisms for reception of more significant sizes of hydro-dynamical forces also enables the operator to change the angle of attack of the wing. The ideal angle will depend on the speed of a ship, height of the waves, and other operational factors. In particular, with application of pneumatic servomechanisms the optimum angle of attack at various speeds can be maintained by modifying the pressure of compressed air, proportional to the square of the speed of a ship. In the long term, the company planned to develop computerized-control system of servomechanisms, automatically synchronizing them to work with movement of waves and supporting optimum values of angle of attack.

Fig. 4. Trolling boat "Kystfanqst" with its two bow-mounted thruster wings lifted from the water while ship is in its berth.

Fig. 5. Trolling boat "Kystfanqst" With bow-mounted thrusters in working position to capture energy of sea waves.

To support continuing development of this thruster-wing, in 1983 the government of Norway gave a grant of 450,000 Kroner. The Institute of Fisher Technology Research is participating in this work also. Successful thruster tests on a research trolling boat "Kystfanqst" with gross tonnage of 180 metric tonnes, and length of 20.4 m (fig. 4 and 5) were carried out in 1984.

The trolling boat is equipped with a rostrum structure to allow the wings to be mounted three meters forward of the bow. The thruster consists of two wings, with two variants, one with the wings of three square meters, and the other of five square meters. Pneumatic servomechanisms are used to maintain the necessary angle of attack. The supporting arm was designed so that this thruster-wing could be taken from the water for realization of comparative tests using engine propulsion. The trial runs which were carried out in 1984 showed positive results. The Wave Control Co. engineer, Ejnara Jakobson, is named as the inventor of this thurster-wing [6]. Company Wave Control Co. has patented the thruster-wing in Great Britain and in other English-speaking countries.

After the positive results received in Norway, intensive research on oscillatory thrusters for extraction of energy from excitement of the sea were undertaken in Japan from 1981-1984. Another big cycle of experimental and theoretical works on application of an oscillating wing for use of wave energy and creation of draft for movement of a large ship was carried out. In recent years, the Institute of Technical Research, along with the company, Hitachi Tsozan in Osaka, have done especially intensive work, and have regularly published detailed reports of their results [2-5]. In 1984, they developed plans for two ships, of lengths 27 m and 300 m respectively, each equipped with thruster-wings for capturing the energy of waves (fig. 6-8).

Fig. 6. The design of a ship with thruster utilizing the energy of sea waves.

Fig. 7. Arrangement of wings (variant 1).

Fig. 8. Arrangement of wings (variant 2).

According to the company Hitachi Tsozan, a 300-meter ship (see fig. 6) can accelerate up to 11 knots with just the energy supplied by the oscillating wings extracting energy from waves, and no engine assistance. When moving into port in the absence of heavy seas, or when an increase of speed is required beyond that supplied by wave energy, power from the ship’s engines will be applied to oscillate the wing more rapidly.

Hitachi Tsozan’s engineers considered that this type of oscillatory thruster has big advantages over a traditional screw-type of thruster (commonly called a “propeller”). The oscillating wing offers a wider range of options in comparison to rotary ships’ propellers. Consider the following special features of an oscillatory thruster:

(a) Extraction of wave energy occurs irrespective of the direction of movement of waves and wind, including counter movement of a ship;

(b) In contrast to a sail, the propulsion does not occupy space on the deck;

(c) The structures below the ship also serve as a stabilizer.

Much work has been done in the past decade toward the creation of thruster-wing systems to enable ships to extract energy of waves [12]. Now in France a new proposal has been offered to create thruster for boats using a wing to capture energy of sea waves. Please see the website : http://kneider.site.voila.fr

As this brief overview shows, mankind frequently invents new ideas, spends money in researching them, and moves on. Previous efforts are forgotten. [13]. Then again man comes back to these ideas, and again discards them. This indicates that new energy sources and technologies are very difficult physical phenomena to control properly. Completely new designs and concepts are necessary for the achievement of a viable and cost-effective technology.

For 75 years there were some attempts to make a boat with wing thruster extracting energy from sea waves. There were even small successes. But the big success was not achieved. Why?

The sea wave interacts with a wing. It is complex physical process. It is nonlinear oscillatory hydrodynamics. The nonlinear oscillatory hydrodynamics is the unknown factor, a poorly-investigated area of a science. Therefore, there is very little scientific data to serve as a basis for calculating this process. That is but a small part of the problem.
A lot of scientific work has been done using quasi-stationary oscillatory hydrodynamics; some are attempting to calculate parameters on the basis of this data bank. But without taking into consideration the full complexity of water’s behavior, this quasi-stationary data will only result in designs that give meager thrust, with less-than optimal extraction of sea-waves energy. Because of their lack of substantial success, the Norwegian and Japanese efforts toward extracting energy from waves have been stopped.

From 1970-1985 both the USA and the USSR carried out some major programs for creating oscillatory thrusters for submarines. In the USSR some hundred millions dollars were spent on this project.

Neither the USA nor the USSR had any success. Both have suspended their efforts. The projects failed because they used the thruster principles derived from quasi-stationary oscillatory hydrodynamics in their development. This was their fatal flaw.

Now in the USA, again work proceeds toward developing thrusters for swimming and flying vehicles — again using the basis of quasi-stationary aero-hydromechanics! With the same fatal flaw in the supporting data, this project will not be a success. Money and time will be spent in vain once again.
Sea waves, wings, suspension brackets for the wings, and the hull of a ship are a uniform complex oscillatory system. It is necessary to know optimum principles of its work in the water environment. Usually developers do not know the theory of oscillatory systems. They are not able to expect such oscillatory systems if they base their work on the usual mechanics and stationary hydromechanics.
Characteristics of a sea wave, rolling and speed of the hull of a ship (or boats) are constantly changing. But it is necessary to provide an optimum mode for extraction of energy from sea waves in order to induce thrust with the help of an oscillating wing (the oscillation being induced by the movement of waves). It is necessary to have a special microprocessor control system. If this system is actively and instantaneously responsive to the wave dynamics, it may be possible to achieve an effective wave-propulsion system without having to incorporate a mathematical model of data concerning the complex behavior of water into the chip and software design.

Once this fatal flaw is overcome and a properly-controlled thruster can extract energy of sea waves, it will be possible to make economically advantageous use of energy that is also easier on the environment. It will be possible to create highly effective boats and yachts, ship moving in full or in part due to energy of sea waves, all from a renewable energy source.

To meet this design challenge, the complex behavior of water must be fully taken into account. And without serious financing the big successes are not possible.

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REFERENCES

1. Evans D.V. Wave-power absorption by systems of oscillating surface pressure distributions // Journal of Fluid Mechanics. - 1982, Vol. 114. P. 481-499.

2. Isshiki Hiroshi A theory of wave devouring propulsion (1nd Report) // Journal of the Society of Naval Architects of Japan. - 1982, Vol. 151. P. 54-64.

3. Isshiki Hiroshi A theory of wave devouring propulsion (2nd Report) // Journal of the Society of Naval Architects of Japan. - 1983, Vol. 156. P. 89-100.

4. Isshiki Hiroshi, Murakami Mitsunori A theory of wave devouring propulsion (4rd Report) // Journal of the Society of Naval Architects of Japan. - 1984, Vol. 156. P. 102-114.

5. Isshiki H. Wave energy utilization into ship propulsion by fins attached to a ship // Proc. 4th Int. Offshore and Polar Eng. Conf., Osaka, Apr. 10-15, 1994. Vol. 3. - Golden (Colo). - 1994, Vol. 3. P. 508-521.

6. Jakobsen E. Folloropellen kanrevolasjonere skipsfarten // Tekn. Ukebl. - 1988, Vol. 135, № 39. P. 10-11.

7. Wu Th. Yao-tsu Extraction of Flow Energy by a Wing Oscillating in Waves // Journal of Ship Research. - 1972, Vol. 16, № 1. P. 66-78.

8. Wu Theodore Y., Chwang Allen T. Extraction of flow energy by fish and birds in a wavy stream // Swimm. and Fly Nature. - 1975, Vol. 2. P. 687-702.

9. Jukovski N.E. About soaring birds // Works part Physical sciences О.Л.Б. - 1892, Т. 4, # 2. (see also the Full collected works. Volume 5. Whirlwinds. The theory covered. Aircraft. M. -L.: Chief edition of the aviation literature, 1937, with. 7-35). (in Russian)

10. Konstantinov G.A., Jkimov JU.L. Calculation of draft thruster a ship using energy of sea waves // АН the USSR. The mechanics of a liquid and gas. - 1995, # 3. C. 139-143. (in Russian)

11. Pavlenko G.E. Use of energy of rocking on heavy sea for movement of ships // L.: Shipbuilding. - 1936, Т. 6. p. 394-401. (in Russian)

12. Senkin JU.F. Experience of creation and use of ships with wave thruster // Internal. Conference “Swimming and flight in a nature and engineering”. AQUAPROP ` November, 95. 27-30, 1995. Saint Petersburg. - 1995. p. 54. (in Russian)

13. Sorokodum E.D. Review of experimental researches flapping thruster // the Report on S (intermediate) "Horizont - 86" on a theme 024.-17.018. State Registration # Г80352 from 30.01.87. The firm “Propeller”. - 1986. 208 p. (in Russian)

14. Jkimov JU.L. Wave thruster of a ship // АН the USSR. The mechanics of a liquid and gas. - 1995, # 3. C. 178. (in Russian)

Wave Propulsion: Brief History and Remedy

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