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July 31, 2021  



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Swimming vehicles with flapping wing


1. Topicality

There are a lot of researches which are carried out in order to create vessels with low hydrodynamic drag and high mobility and economy. These researches are supported by the great number of grants and investments. The result is still dim, since most of the work done base on principles of classic hydrodynamics.
Non-linear oscillations hydrodynamics can open new horizons in this field. The same evolution steps were taken by animals, which are capable of flying and swimming. There are a number of tries made to use oscillatory motion in order to create lift and thrust. USA has a number of active programs, where the main purpose is to create oscillating type thruster. In spite of the big investments, there is no guarantee that such devices will be developed, due to the above mentioned reasons (work is being done on the basis of old principles).
It's impossible for modern ships and underwater vehicles to reach new technologies on the basis of stationary hydromechanics (fig. by T.E. Bearden).
Non-linear oscillator hydrodynamics and view of the vehicle as whole system can radically change set trends. It is not an easy task, since discovered principles relatively recent and they are presented by a number of small works and publications. The situation becomes even worse, since the scientists are not definitely agreed that the field of physical phenomena can be described by means of non-linear oscillator hydrodynamics. Not all possibilities are known, or thoroughly researched, such as: annihilation of hydrodynamic drag to the zero, producing of lift many times grater, then it is possible to produce by classical principles of hydrodynamics.

2. Reserch of a thruster of a oscilative type

Basing on research works made by numbers of scientists and our own researches we came to conclusion that it is possible to make a breakthrough in upgrading characteristics of hydrofoil ships proceeding to study of engine-thruster complex of oscillative type. Upgrading of characteristics becomes possible due to using:
- Oscillating hydrofoils and oscillating hydrodynamics for developing thrust
- Nonlinear hydrodynamic oscillating conditions for thrust augmentation
- Jukovsky-Knoller-Betz effect (wave flow-around effect) to reduce hydrodynamic resistance of fixed hydrofoils
- Drives of oscillative type
- Method of adaptive optimal control of engine-thruster complex characteristics
- Ship maneuvers steering system and adaptation to sea waves characteristics

We offer to produce a hydrofoil ship (boat) when lift force is produced with the help of fixed hydrofoils and thrust is produced with the help of oscillating leading edge flap. These questions will be enlightened in more details below.

2.1. Increasing of effective thruster swept area

Using thrust augmentation effect while reduction of pressure head in thruster hydrodynamic swept area.
This method is well known among specialists studying thrusters. But this effect cant be used to a full extend because wide thruster swept area is needed for that. And for some economic reasons it is impossible (screws of extra-large diameter will be necessary; that means considerable weight, problems with high-drag and failure resistance, extra weight of engine-thruster complex because of necessity to decrease screw revolutions). Oscillating wing gives relatively simple problem solution because a thruster in the form of oscillating wing can be situated along leading and trailing edge of a fixed wing. This will allow a huge thruster swept area (even more than 10 times larger than a common propelling screw can), thrust augmentation and higher coefficient of efficiency.

2.2. More efficient usage of a thruster swept area

A thruster called oscillating wing doesnt have disadvantages of a propelling screw: thrust deficiency of a screw near axis, inductive aerodynamic drag at the ends of the blade, damaging air motion to the ends of the blade caused by centrifugal force.

2.3. Extension of effective thruster swept area (KNOW HOW)

There are modes of nonlinear hydrodynamic oscillation of wing when the effective swept area is much larger than the wing swept area at stationary oscillation mode. Due to this effect thrust value can be exceeded.

2.4. Thrust increases because while oscillation vortex separation from the wing occurs at large angle of attack (KNOW HOW)

Propulsive thrust of oscillating wing type is projection of a lift force on direction of a ship motion. During wing oscillations flow-around stall will occur at much larger angles of attack. As the result, lift coefficient and propulsive force will have much larger value than that of the propelling screw.

2.5. It is easy to modify optimum modes using a thruster of oscillating wing type over a full range of speeds (KNOW HOW)

Propelling screw doesnt have optimum angles of attack at different floating speeds. Even propelling screw with flexible blade cant fully solve this problem. It is easy to fix optimum angles of attack and oscillation principles remotely. It will lead to exceeding of propulsive thrust and coefficient of efficiency.

2.6. A thruster of oscillating wing type will serve as a thruster and a guidance blade simultaneously (KNOW HOW)

Existing hydrofoil ships have ordinary steering wheels for that purpose. We offer to use oscillating wings of a thruster as a rudder. By means of that we can get positive result:
- Ship will be successfully controlled at low speeds, including maneuvers on site, and also while ship hull comes out of water and submerges.
- There will be no need to produce special rudders.

2.7. Lift force increase via directional change of a central thrust vector (KNOW HOW)

2.8. Lift force increase through circulation augmentation

When lifting of mid position of oscillating leading edge flap (KNOW HOW)

2.9. Light trace (KNOW HOW)

Hydrofoils and a thruster leave a slight water trace.

2.10. Drive simplification

Due to application of hydraulic drive to cause oscillations of a leading edge flap, power transmission from engine to actuating hydraulic cylinders that oscillate leading edge flaps becomes easier. Drive units, shafting and vertical columns with bevel gear, etc. are no longer needed.

2.11. Easy and low-priced production comparing to screws (KNOW HOW)

A wing of a thruster is easy in production (symmetrical profile and the chord is equal spanwise).

2.12. Improving of ship course-keeping qualities, specifically on low and zero speed.

It can be achieved with the help of a thruster of oscillative type (KNOW HOW).

2.13. Extraction of sea waves kinetic energy (KNOW HOW).

See link: E.Sorokodum and Francois Kneiders, Edited by: Mary-Sue Haliburton and Sterling D. Allan "Wave Propulsion: Brief History and Remedy" /Pure Energy Systems News - Exclusive, Sept. 21, 2005

2.14. Controlling system of engine-thruster complex of oscillative type.

We produced several controlling systems:

Thruster characteristics (frequency and amplitude of oscillations) hand control unit

A unit for automatic determination of thruster optimal characteristics (first sample)

A unit for automatic determination of thruster optimal characteristics (second sample)

Boats and ships we propose will:

1. Have less engine power because less thrust is needed;
2. Have less weight of engine, transmitting elements, fuel and fuel system;
3. Have less displacement transporting the same commercial freight;
4. Will have cheaper price;
5. Commercial transportations will be cheaper;
6. Will have higher transportation safety and improved course-driving and maneuvering qualities;
7. Will be safety for fish and swimming people; sea ores and nets dont wrap round;
8. Have less rigid requirements to location of power-units and control systems on the ship;
9. A ship with oscillating thrust has more aesthetical Physical configuration than one with a screw;
10. Improvement of course-driving qualities in conditions of sea disturbance;
11. Extract kinetic energy of sea waves.

3. Our production and services.

We can make research and developmental work on creation of the first samples of new highly effective technics (on the basis of our theoretical and experimental researches). We search for investors and partners for creation of the first samples of this new technics. It is possible:

1. To develop and make the first samples thruster oscillatory type for underwater vehicles.

2. To develop and make the first samples thruster oscillatory type for boats and courts.

3. To develop and make the first samples thruster oscillatory type for boats on underwater wings.

4. Participation in your projects on decrease of hydrodynamical drag of your vehicles.

5. Research and development alternative thruster creating force due to a gradient of energy

6. Performance of research and settlement --design works under your orders:

  • Drawing up of the atlas of hydrodynamical characteristics of a flapping wing for a mode kwazi stationary oscillations
  • Drawing up of the atlas of hydrodynamical characteristics of a flapping wing for a mode nonlinear oscillatory
  • Development of a design of a flapping wing for underwater vehicles
  • Development of a design of transmitting-agreeing elements for the coordination of kinematic, dynamic and power characteristics between the engine and hydrodynamical loading of a wing
  • Development and manufacturing of system of a drive for oscillation of wings
  • Development and manufacturing of control system for underwater vehicles with flapping wings
  • Development and manufacturing of system of adaptive optimum control for underwater vehicles with flapping wings
  • Techniques and programs for experimental researches
  • State-of-the-art reviews of scientific publications on hydrodynamics flapping wings
  • State-of-the-art reviews of patents of underwater vehicles with flapping wings
  • State-of-the-art reviews of designs of underwater vehicles with flapping wings.

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: 2004-08-04 (10887 )

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