The Forces on an Aerofoil at Very Low Speeds

Summary The forces on an aerofoil have been measured at various angles of incidence for 0.5 < R < 2,000. Below R = 2 the lift is found to be given approximately by :— L , = (3/2) µ lV sin 2 x and the drag at all angles of incidence tends to: D = µ lV . An approximate theoretical estimate is also given of the effect of spacing, on the drag of a series of flat plates at R → o.