Bilge planing craft with constant wet length

Abstract

The invention discloses a sharp-bilge planing boat type with constant wetted length. A boat body curved surface is a fairing space closed curved surface formed in a controlling mode with a designed water line, a midship longitudinal section line, an angle folding line, an upper boundary line, a stern transverse section line, a midship section line, a folding angle line longitudinal inclined angle, a stern inclined rising angle and a midship inclined rising angle as characteristics. The sharp-bilge planing boat type has the advantages that the wetted length is constant and unchanged no matter how the ship state changes at various kinds of ship speed; the resistance performance is greatly reduced than that of a traditional planing boat when sailing in states of water draining, transiting and taking off; the resistance performance is close to that of the traditional planing boat when sailing in a planing state; maneuverability, seaworthiness and seakeeping are greatly improved. The sharp-bilge planning boat type can be used in sea conditions 1-2 grades higher than the traditional planing boat. Further, due to the fact that the wetted length remains unchanged, the sharp-bilge planning boat type is more favorable for people to utilize the length Froude number to analyze and study the performance of the sharp-bilge planning boat type theoretically.

Description

technical field [0001] The invention relates to a planing boat type, in particular to various types of planing boats capable of normal navigation under relatively high sea conditions, and belongs to the technical field of ship types. Background technique [0002] A planing boat is a small boat that slides at high speed on the water surface. It is widely used in military and civilian fields, such as torpedo boats, missile speedboats, high-speed traffic boats, high-speed luxury yachts, high-speed racing boats, etc. The shape line design of a planing boat is related to various performance indicators of the planing boat. A slight difference in the shape line may sometimes cause a great difference in performance. Whether the shape design is good or not is directly related to its sailing performance. Normal sailing, so how to design an excellent planing boat has become one of the most important topics for shipbuilders to study. When the traditional single-body planing boat with s...

AI Technical Summary

Problems solved by technology

When the traditional single-body planing boat with sharp bilge sails in the low-speed displacement state, because the length-width ratio of the planing boat is small and it has a sharp bilge, it has greater wave-making resistance compared with displacement ships; at the same time, because the traditional single-body sharp bilge When the planing boat takes off, its wetted length will be significantly reduced, and the wetted aspect ratio will be greatly reduced. At this time, there is an obvious wave-making resistance peak, and the wave-making resistance is relatively large; When sailing at high speed, since the planing boat is gliding on the water surface, the draft is reduced, the bow is lifted, the submerged length is reduced, and the submerged width is basically kept unchanged, so that the contact surface area between the hull and water is greatly reduced , although the wave-making resistance decreased significantly, but at the same time, the droplet resistance appeared again; due to the substantial reduction in the length of immersion, the longitudinal motion stability of the sharp-billed planing boats was greatly reduced, and some sharp-billed planing boats were due to the The kinematic stability performance deteriorates to the point that it cannot sail normally and the whole boat is scrapped; due to the substantial reduction in the length of immersion, the maneuverability and seaworthiness of the sharp bilge planing boat are deteriorated, and the sharp bilge The seakeeping performance of the planing boat becomes worse, and even it cannot sail normally under slightly higher sea conditions, thus limiting the range of operating conditions of the traditional sharp bilge planing boat

Different from the conventional displacement ship, the sharp-billed planing boat is a dynamic-lift ship. When sailing, its navigation state will change with the change of the speed, mainly the wetted length of the hull, the draft of the hull and the body pitch angle changes, which brings inconvenience to analyze its performance with length Froude number

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