Boosting Aeroengine Thrust by Using Ramjets

Propulsion programmes have recently been showing continuing efforts to improve factors such as efficiency, emissions, performance, and cost. Lamb suggested an arrangement shown in Figure 1 in which the combustion air is fed to the combustion chambers (d) on the rotor (c) by a centrifugal compressor (a) driven by the rotor (c) through a layshaft gear (k), the rotor being enclosed in a casing (g) into which the exhaust gas from jet nozzles (f) is passed to preheat the combustion air. Drive for the propeller is taken via a second layshaft (n). This system is limited to shaft power applications such as helicopters. It also employs a tip combustion rotating system.