An investigation into the effect of forced and natural afterbody ventilation on the hydrodynamic characteristics of a small flying boat (saro 37) with a 1 : 20 fairing over the main step

Abstract

In continuation of the tests reported in R. & M. 2463, an investigation was made into the hydrodynamic qualities of a small flying boat (Saro 37) with a 1 : 20 double curvature fairing over the main step. As before, the aircraft was equipped with means for forced and natural ventilation of the afterbody. Apart from the 1 : 20 fairing, the Saro 37 hull is a 1 : 2-75 scale model of a larger flying boat (Shetland), of 19.0,000 lb all-up-weight. Forced ventilation was supplied by an auxiliary power unit driving a centrifugal air compressor. The fairing was ventilated by three sets of ventilating ducts--one set immediately behind the main step, an intermediate set at 30 per cent beam aft of the step, and an aft set at 90 per cent beam aft of the step, i.e., at the inflexion line of the 1 : 20 fairing. Only the forward ducts were force ventilated in the present tests.