Stability and maneuverability of these ships with winds and cross waves.
The ground effect vehicles that use water propellers as propulsion systems, in general, have drawbacks in the stability and maneuverability of the boat when it moves at high speed with winds and cross waves, as was the Ferry project Seabus-Hydaer of ground effect and high speed investigated by the European Union between 1997 and 2000 and which was frozen and abandoned after finding significant drawbacks in the maneuverability and stability of this type of boat when the boat is moving at high speeds with cross winds and waves.
This Ferry Seabus-Hydaer investigated years ago by the European Union, used gas turbine combustion engines and water jet propellants for its propulsion and had a design speed of 125 knots (231.5 km/h) and could transport 800 people and 100 cars.
Figure 6: Ground effect boat powered by electric motors and propellers composed of supercavitating propellers or water jet systems.
One way to reduce the harmful effect of crosswind action against the lateral stability of the boat when moving at high speeds is by using multiple propulsion systems, each consisting of electric motors and propellers with Azimuth control systems of the position of the propulsion systems, where each of the propellers has the possibility of changing the direction independently of each other but in a coordinated way among all of them to be able to orient the wing structure of the boat and be able to perform the turns and bending it in the desired way in order to "orient" the wing structure of the vessel at any time in the way necessary to avoid the harmful action of crosswinds on the lateral sides of its wing structure.
Figure 7: Ground effect vessel with supercavitant propellers and hydrofoils oriented to move in the same direction as the wind and waves.
When this ground effect
boat is moving for or against the wind but with a direction that coincides with
the direction of the wind, all the propulsion units formed by the electric
motor, the propeller and the hydrofoil will all be "oriented" in the same
direction as the direction of movement of the boat, as shown in Figure 7.
But when there are winds and cross waves to the direction of travel of the vessel at high speed, as in this example of Figure 8, the angle between the direction of travel of the vessel and the Resultant of the wind acting on the wing structure of the boat, which is what most complicates the lateral stability and the maneuverability of the boat, is 8 °. Therefore, if we rotate “all” the independent propulsion units formed by the electric motors and the propulsion propellers that same angle, both in the bow and stern thrusters (as shown in Figure 9), the direction of the wing structure of the vessel will be "aligned" with the direction of the resulting wind acting on the vessel, thereby minimizing the harmful effects of lateral destabilization of the crosswind on the wing structure of the vessel, being able to significantly improve the stability and maneuverability of the boat, and it will also improve and decrease the value of the resistance to advance generated by the wind and the cross waves when it acts on the boat at high speed.
Figure 9: Ground effect boat with supercavitant propellers and hydrofoils oriented to move in a different direction than the direction of the wind and waves.
With this independent rotation system of the propulsion systems to "align" the wing structure of the boat with the resulting wind direction that acts on its wing structure when the boat moves at high speed, we will reduce the harmful effects of the wind on the boat, but we will not completely diminish the harmful effects that the cross wave will also have on the underwater propulsion systems of the boat, but in general, the effect of the cross wave on the immersed jets in the water (once resolved the harmful effect of the cross wind over the wing structure of the ship) will be similar to the effects and destabilization generated by the cross waves in vessels only with hydrofoils, and whose effect is often practically negligible in the operation of such vessels only with hydrofoils.
With this steering system of the wing structure of the vessel as needed, it will be possible to significantly reduce or directly solve the problems of stability, maneuverability and increased resistance to advance generated by winds and cross waves on the normal operation of the vessel. boat; But the cross waves with which this boat can operate should not exceed certain heights at which it is impossible for the boat to navigate with a high wave height that will also occur with the wind or the waves in the same direction of the boat.
Therefore, I think it may be interesting and necessary to study and investigate the application of this type of electric-solar propulsion system in this type of ground effect vehicles propelled by water propellers, given the interesting characteristics of high speed and relatively low energy consumption. that could have this type of high-speed vehicle, given the growing interest in the application of solar energy in naval transport systems and the fact that it is possible to use this type of ground-effect vehicles propelled by water propellers both in high speed ferries, such as large and medium recreational yachts, and coastal patrol or coast guard vessels.
As the maximum ratio of the lift coefficients Cl and drag Cd is 65, for the chosen wing profile, we consider for the calculation of the fuel consumption of the boat to values of the ratio R = L/D, of the order 30, 40 and 50.
Considering that a good ratio between the transported load and the empty dead weight of the vessel for short voyages can be 1,2 ; but if the trip is long distance, where it would be necessary to carry a lot of weight in electric batteries or fuel or if the own weight of this WIG HydAer would be high, the relationship between the transported load and the empty weight of this boat may fall to a value estimated 0.8.
In principle, according to the results obtained, this type of WIG HydAer would be justified as a use for the transport of light or intermediate loads, or of people in short and intermediate distances, as is the case of current ferries, luxury yachts or coastal patrols ships. And what would also be interesting, especially that it can be used in refrigerated or high-value loads for intermediate or long distances of up to 4,000 or 5,000 km at a higher speed than current container ships but at a lower cost than transporting them by plane.
At this moment I am trying to make an experimental prototype of this high speed electric-solar boat to be able to verify the feasibility of its correct operation and I am looking for interested parties in carrying out and being able to carry out this experimental prototype both in Argentina and in the rest of the countries. of the world.
If you are interested in this project you can contact me at email: