Patent Application
20080070455
The present application describes a mono-hull structure with improved stability and less fuel-consuming. The mono-hull structure is suitable for water surface boats powered by engine propulsion, such as yachts, marine transportation boats and like displacement boat implementations. “Displacement boat” means that the boat vessel glides smoothly through the water, in contrast to the “planing boat” which rises up on top of the water.
As shown, the V-shaped profile of the hull body 102 near the bow 104 forms two flank portions converging and joining at a keel centerline 103. The bottom surface 108 is formed with a profile that continuously narrows and slopes from the stern 106 deeper toward the bow 104 to merge with the keel centerline 103 proximate to the bow 104. Accordingly, the bow 104 has a profile which sharpens downward to promote water penetration. A keel 101 is provided along the keel centerline 103 on the bottom surface 108 of the hull body 102. In the illustrated embodiment, the keel 101 extends substantially from the sternpost toward the bow 104.
Referring to
The front end 117 of each bulge 112 has a converging profile which merges with the shape of the hull body 102. To separate the propulsion compartments 114 with a maximal distance, the bulges 112 may protrude from locations respectively adjacent to two chines 107 of the hull body 102 linking the bottom surface 108 with the port and starboard flanks 109. The front end 117 of each bulge 112 preferably is proximate to the middle of the hull length. As illustrated, the bulges 112 is formed with a continuous streamlined profile having a generally oval shape in a section transversal to the lengthwise axis of the hull, similar to a torpedo or bullet shape. The bulges 112 and the hull 100 may be formed as a single body.
As illustrated in
To accommodate the propeller shafts 124 and its blades 128, the bottom surface 108 of the hull 100 may include a concave portion 105 respectively located above each of the propeller shafts 124 at the two sides of the keel 101. The two concave portions 105 extend lengthwise approximately from the tail ends 116 of the bulges 112 to the sternpost. The concave portions 105 allow a greater diameter of the blades 128 to be placed underneath, and its curved profile may be configured to improve the hydrodynamic flow generated by the propeller blades 128 along the bottom surface 108.
Referring to
According to an embodiment, a boat vessel provided with a hull design of this invention floats motionless with the propulsion compartments 114 under the water plane. At a cruising speed, the boat vessel displaces through water with the bulges 112 of the propulsion compartments 114 substantially under the water plane. This hull configuration according to the present invention provides at least the following features and advantages.
The propulsion compartments 114 entirely lodging the engines 122 below the bottom surface 108 of the hull 100 displaces the center of inertia of the boat substantially downward, and spaces apart the significant weight of each propulsion block along the width of the hull body 102. As a result, the V-shaped hull substantially gains in stability against side and front waves, and rolling effects can be advantageously reduced. The placement of the propulsion compartments 114 also enables to move the center of inertia of the vessel toward the middle of the hull body 102 where, according to an embodiment, the fuel tank can also be placed. As a result, undesirable inclination of the boat vessel due to a variation of the fuel level, which affects the hydrodynamics of the boat vessel, can be advantageously prevented.
Other advantages are provided with the placement of the engines 122 in two independent and isolated propulsion compartments 114 below the bottom surface 108 of the hull 100. More space becomes available and the hull capacity is increased. Further, the isolation of the propulsion compartments 114 below the bottom surface 108 of the hull 100 can effectively prevent noise propagation and amplification generated from the engine operation. In addition, it can effectively prevent any damages to one propeller engine from propagating and affecting the other engine. More particularly, if one compartment is subject to water infiltration, the other one being completely separated from the damaged compartment will not be affected. A boat vessel provided with the mono-hull design according to the invention thus has improved safety and comfort in navigation.
According to another advantage, the arrangement of the propulsion compartments 114 below the bottom surface 108 of the hull 100 allows an adjustment of the propeller shaft angle as desired. In the illustrated embodiment, the propeller shafts 124 are configured parallel to the water plane 130, e.g. at zero angle axis. The rotation of the blades 128 thus can provide an optimal thrust to more efficiently propel the boat vessel. As a result, the boat consumes less fuel. As described below in conjunction with
The foregoing only describes some of the advantages of the invention, and many other advantages and features stemming from the inventive concepts described herein will be apparent to a person skilled in the art.
The hull according to this invention may be built with materials such as fiberglass, wood, steel, or composites. A person skilled in the art will appreciate that a combination of these materials would also be possible. In addition, the dimensions of the hull may vary according to the boat design requirements and specification. In an example of implementation, a yacht vessel designed according to this invention may have a hull length of about 28 meters, a height of about 3 meters, and a beam width of about 6 meters. The bulges lodging the propulsion compartments may be located at about 12.5 meters from the bow of the hull, and have a length of about 11 meters. The keel height taken at the sternpost is about 1.5 meters. The distance between the bottom surface of the hull and the axis of the propeller shaft is about 0.9 meters. The draft is about 2.26 meters for a vessel weighing about 150 tons. It will be understood that the hull design according to this invention is not limited by the foregoing dimensions, which may be adjusted according to the design requirements.
The hull design according to this invention is suitable for high speed as well as moderate speed cruises with good stability. At high speeds, a boat with the hull design according to this invention can reach 50 kms/hr with a substantially stable navigation. Of course, the highest cruising speed of the boat vessel may be increased by providing more powerful propeller engines. Though the embodiments described herein make reference to a specific propeller drive, the hull design according this invention may be suitable with any propulsion means in general.
Realizations in accordance with the present invention therefore have been described in the context of particular embodiments. These embodiments are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Structures and functionality presented as discrete components in the exemplary configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of the invention as defined in the claims that follow.
