Sails of Silver now sported the same line-up that had brought it to the height of its success, "Sails of Silver" has often been seen as embodying a different spirit from their classic albums of the 1970s. Prior to "Sails of Silver", the band had always performed songs written by other people, predominantly traditional songs, but also a few 20th century pieces, such as the two Brecht songs on "Storm Force Ten". But on this album they included several songs they had written themselves, including "Let Her Go Down" and "Senior Service". This was the beginning of a trend that continues down to
Forces on sails Researchers plot pressure across the windward and leeward sides of test sails along the chord and calculate pressure coefficients (static pressure difference over wind-induced dynamic pressure). Research results describe airflow around the sail and in the boundary layer. Wilkinson, modelling the boundary layer in two dimensions, described nine regions around the sail: Sail design differs from wing design in several respects, especially since on a sail air flow varies with wind and boat motion and sails are usually deformable airfoils, sometimes with a mast for a leading edge. Often simplifying assumptions are employed when making design calculations, including: a flat