The present non-provisional patent application claims the benefit of foreign priority to copending Indian non-provisional patent application Ser. No. 202311062497, filed on Sep. 18, 2023 and entitled “THERMAL MARINE PROPULSION SYSTEM”, the complete disclosure of which is expressly incorporated herein by reference in its entirety for all purposes.
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The invention generally relates to marine propulsion systems and, more particularly, but not exclusively, to non-mechanical marine propulsion systems.
Typically, watercrafts propel by a thrust generated by mechanical systems consisting of an electric motor or an internal combustion engine driving a propeller, or less frequently, in pump-jets, an impeller.
Mechanical active roll stabilization systems produce a torque to oppose roll of a waterborne watercraft by moving masses like anti rolling tanks and active moving weight or by using control surfaces like active fins by means of power.
The mechanical systems are bulky, unreliable and expensive. Moreover, drag between a cruising watercraft and surrounding water limits maximum-speed, maneuverability and fuel-efficiency of the watercraft.
Accordingly, it is a general purpose and primary object of the present invention to provide a non-mechanical system for marine propulsion via pressure-difference. The system comprises heating-elements symmetrically installed at submerged-regions of bow and stern of a waterborne watercraft, wherein hot-sides of the heating-elements are configured to boil water around the submerged-regions. The resultant steam-filled regions around the heating-elements are at a lower-pressure than water in which the watercraft floats. Thus, activating the heating-elements installed at the bow and deactivating the heating-elements installed at the stern generates a steam-filled low-pressure region ahead of the bow and a water-filled high-pressure region behind the stern, thus a forward-thrust due to a pressure-difference between the regions propels the watercraft forward, and vice-versa. Also, the watercraft can be steered sideways by application of an asymmetric thrust produced by unequally heating the heating-elements in lateral-halves (left and right) of the submerged-regions.
In one embodiment, a non-mechanical active roll stabilization system is provided that includes one or more fixed-fins attached to submerged-region of hull of the waterborne watercraft, and each of the one or more fixed-fins has two heating-elements joined together at a camber line such that respective hot-sides form two airfoil-surfaces, one of which when heated by a control-unit, displaces surrounding water by boiling and resultant pressure-difference between the airfoil-surfaces produces a torque to counteract roll of the watercraft.
Moreover, the non-mechanical systems are more compact, reliable and affordable than their mechanical counterparts; and the steam-filled region offers lesser drag than water, thus increasing maximum-speed, maneuverability and fuel-efficiency of the watercraft.
The invention is described with reference to the accompanying drawings, wherein:
The marine propulsion system of the present invention comprises heating-elements, preferably plate-like, each with a hot-side. The heating-elements are symmetrically installed to form or cover regions of bow and stern of a watercraft such that the heating-elements are submerged and respective hot-sides make contact with surrounding water when the watercraft is waterborne. Consider a scenario wherein the heating-elements installed at the bow are activated by a control-unit, thereby causing the respective hot-sides to boil surrounding water and generate a steam-filled region ahead of the bow. The steam filled region is at a lower-pressure than water in which the watercraft floats because the surrounding water gets displaced in form of rising steam upon boiling, thereby leaving behind a partial-vacuum. In the meantime, if the heating-elements installed at the stern are deactivated by the control-unit, then high-pressure region of water behind the stern generates a forward-thrust required to propel the watercraft. Note that, the forward-thrust is proportional to pressure-difference between the high-pressure region and the lower-pressure region, which in turn, is proportional to absolute-value of difference of sum of input-powers to the heating-elements installed at the bow and sum of input-powers to the heating-elements installed at the stern. Conversely, the heating-elements installed at the bow are deactivated and the heating-elements installed at the stern are activated in order to generate a reverse-thrust.
The steam filled low-pressure region offers lesser drag to the watercraft than liquid water and a turbulence resulting from the rising steam has a self-cleaning effect against biofouling.
Moreover, one or more heating-elements in a lateral-half (left or right) of the bow and one or more heating-elements in an opposite lateral-half (right or left) of the stern are heated more than one or more heating-elements in each of respective adjacent lateral-halves so as to generate a net asymmetric thrust that steers the watercraft sideways during cruise or even while being stationary. Note that, turning-radius of the watercraft during cruise is proportional to angle between the asymmetric thrust and longitudinal-axis of the watercraft.
Finally, a non-mechanical active roll stabilization system of the present invention includes one or more stabilizing-fins fixed to submerged-region of hull of the waterborne watercraft, and each of the one or more fixed-fin has two heating-elements joined such that respective hot-sides form two airfoil-surfaces, one of which when heated by a control-unit on receiving a control-signal from a sensor device, boils surrounding water and forms a steam-filled low-pressure region whilst opposite airfoil-surface being cold remains in contact with water in which the watercraft floats. Hence, a force acting on the stabilizing-fin that is proportional to a pressure-difference between the two airfoil-surfaces produces a counteracting torque opposite to roll of the watercraft, wherein the pressure-difference is proportional to input-power to the heating-element being heated. Note that, magnitude and direction of the torque is determined by magnitude and direction of the force.
The invention has been described in detail with particular respect to implementations thereof, but it will be appreciated that variations and modifications can be effected within the spirit and scope of the invention. For example, a variety of heating-elements might be employed, including a thermoelectric (Peltier) heat-pump, an electric heater or a fossil-fuel-fired furnace. Further note that the systems of the present invention might be built into hull of the watercraft or installed separately onto surface of hull of an existing watercraft as an upgrade. Finally, while the invention is cast in the environment of watercrafts like ships and submarines, it has other uses, for example, in connection with aircrafts.
Number | Date | Country | Kind |
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202311062497 | Sep 2023 | IN | national |