Investigation of weight reduction in a thrust reverser cascade using aerodynamic and structural integration

This paper focuses on the design of a cascade within a cold stream thrust reverser, see Figure 1. Methodologies for weight reduction during the design process are established using the simulation methods of computational fluid dynamics (CFD) and finite element analysis (FEA). Aerodynamic and structural simulations were carried out using realistic operating conditions for three different design configurations. Results show that total reverse thrust decreased by 0.28% when the aerodynamic performance of the deformed cascade vanes was compared to the un-deformed case. This shows that for the conditions tested, the deformation of the cascade vanes had no significant affect on aerodynamics. Although the degree of reverse thrust was reduced by 9% for two weight reduced designs, it was found that in both cases, the maximum air speed within the thrust reverser was sub-sonic. The maximum airspeed was above Mach 1 for the original design. The cascade vanes in the weight reduced designs will therefore, not be subjected to the shock waves associated with supersonic air flow. Having reduced cascade weight by 5% and then 10% by modifying the vane configurations, it was found that the structural performance of the cascade vanes improved with significantly reduced levels of vane displacement and stress. The affect of any design changes on lifecycle cost and ease of component manufacture will also have to be taken into consideration before any firm conclusions are drawn regarding the final cascade configuration.