|
A sailing hydrofoil, hydrofoil sailboat, or hydrosail is a sailboat with wing-like foils mounted under the hull. As the craft increases its speed the hydrofoils lift the hull up and out of the water, greatly reducing wetted area, resulting in decreased drag and increased speed. A sailing hydrofoil can achieve speeds exceeding two times the wind speed. Both monohull and multihull sailboats can be retrofitted with hydrofoils, although greater stability can be achieved by using the wider planform of a catamaran or trimaran. ==Typical configurations== Some multihulls use three foils; two main forward foils provide lift so that the boat "flies" while a horizontal foil on the rudder is trimmed to drive and control altitude. On catamarans, a single main foil can be attached between the hulls just in front of the center of gravity and at 2 degrees of incidence, spanning the tunnel with supporting struts. Hydrofoil catamarans are also called foilcats. Multihull sailboats can also employ hydrofoils only to assist performance. Just as daggerboards and rudders are foils that enhance the control of a boat, assisting hydrofoils provide lift to the hull to reduce the wetted area without actually lifting the boat completely out of the water. Monohull boats typically employ a "ladder" arrangement of hydrofoils splayed out with a dihedral angle of 50 degrees, with a stabilizing rudder foil. One of the earliest examples is the ''Monitor'' boat from 1957.〔(【引用サイトリンク】 title=Monitor specs )〕 This design offers the advantages of maximum lifting foil area at slow speeds and less at higher speeds, with rolling resistance arising from the dihedral support of the outboard ladder foils. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「sailing hydrofoil」の詳細全文を読む スポンサード リンク
|