High Performance Reefable Wingsail Feasibility Study

具有襟翼的翼帆类似于客机机翼在起飞和着陆时使用的襟翼，以增加在相对较低的空速下可用的升力，可以比类似尺寸的传统帆产生明显更多的驱动力，并且更接近风航行。这允许使用具有较低桅杆高度的较小帆，使其对港口装卸作业的阻碍减少，并提高航行性能。目前具有整体桅杆的高性能刚性框架翼帆，如F50双体船，需要起重机来装配/每次使用时都要把船拆下来，因为翼帆不能安全地长时间放置，而且要有一个机库来存放它。目前更实用的替代方案翼帆：* 可以以类似于可折叠纸灯笼的方式降低，其中帆的降低部分只是简单地折叠起来，这一过程有效地禁止使用由增强聚酯薄膜等板材制成的高效现代帆布或 * 通常由双帆表面组成，这些表面实际上都是传统的软帆，并且依赖于不受内部框架支撑的板条的刚度来保持帆的形状。这导致帆在强风下变形时往往会有更大的曲率，而相反的是为了减少驱动力以保持在这些条件下对船的控制。本项目研究了使用基于刚性横向框架的高性能可收帆/可卷帆的实用性和经济可行性，该框架可以拉直以允许两侧的帆覆盖层剥落或卷拢。除了桅杆底部附近的过渡区之外，帆布/薄膜面板始终处于单一曲率，其中曲率过渡足够平缓以避免起皱。这允许具有膜基帆布/覆盖物的刚性翼帆的性能优点被保留，同时允许帆覆盖膜被收起或完全移除，同时将桅杆留在适当位置，如对于大多数海滩猫和巡航游艇通常所做的那样。一艘适合伤残（及健全）船员使用的6.5米三体船、一艘15米双体船及一艘远洋邮轮，以及将其改装至现有机动船只的技术可行性，均在考虑之列。

Wingsails with flaps analogous to the flaps used by an airliner wing when taking off and landing to increase the lift available at relatively low airspeed can generate significantly more drive than a conventional sail of similar size as well as sailing closer to the wind. This allows the use of a smaller sail with a lower mast height, making it less obstructive to loading/unloading operations in port as well as enhanced sailing performance.Current high performance rigid framed wingsails with integral masts such as the F50 catamarans need a crane to rig/derig the boat every time it is used as the wing sail cannot be safely left up for long and a hangar to store it.Current more practical alternative wingsails either:* Can be lowered in a manner similar to a collapsible paper lantern in which the lowered part of the sail is just simply crumpled up, a process which effectively prohibits the use of efficient modern sailcloth made from sheet materials such as reinforced mylar or* usually consist of double sail surfaces that are effectively each a conventional soft sail and which rely on the stiffness of their battens unsupported by internal framework to maintain the shape of the sail. This results in a sail that tends to have greater curvature as it gets deformed by strong winds, whereas the opposite is required in order to reduce drive to maintain control of the boat in these conditions.This project studies the practical and economic feasibility of using high performance reefable/furlable wingsails based on rigid transverse frames which can straighten out to allow the sail covering on either side to be flaked or furled. The sailcloth/film panels are always in single curvature apart from a transition zone near the base of the mast where the curvature transition is gentle enough to avoid crumpling. This allows the performance advantages of a rigid wing sail with film based sailcloth/covering to be retained while allowing the sail covering film to be reefed or removed altogether while leaving the mast in place as is typically done for most beach cats and cruising yachts.Economic feasibility of using this rig as the primary means of propulsion for three multihull vessels, a 6.5m daysailing trimaran suitable for disabled (and ablebodied) crew, a 15m catamaran ferry and an oceangoing cruise ship is considered as well as the technical feasibility of retrofitting it to existing motor vessels.