The Stresses in the Wall of a Duct Available to Purchase

WITH the advent of auxiliary blowers and the fashion for wing entry air intakes, the designer of the modern aircraft power plant has been set the problem of duct design. The installation of to‐day is very compact and it has been found that ducts passing between the engine and various components, wing entry and blower, etc., are forced to take up unsymmetrical shapes in order to clear the major structural components of the power plant. The question of the efficiency of the ducting from an aerodynamic aspect has been thoroughly investigated and the results of mathematical and practical investigations published for the benefit of the designer, but to the knowledge of the writer, little, if any, work has been carried out on the strength of these components. Nevertheless, the efficiency of a duct from strength considerations is most important, as the power lost by the engine due to a failure of a duct may be considerable and lead to disastrous results at high altitudes.