Thermo-Elastic mechanics of Morphing Lattice Structures with Application in Shape Optimization of BLI Engine Intakes

Abstract

The boundary layer ingesting (BLI) engine configuration has been theoretically proven to reduce fuel burn compared to conventional engine configuration. This reduced fuel burn, can be potentially offset by reduced stability and efficiency of the fan stages due to the distorted flow. This thesis presents a novel shape morphing strategy of a BLI engine's duct employing 3D lattice materials. The aircraft's intake engine duct morphs from an ideal shape with minimized flow distortion to a shape that optimizes pressure recovery. The duct was modeled using bi-material lattices with varying elastic, thermal conductivity, and thermal expansion properties. The lattices and the external thermal boundary were varied functionally while subjected to convective and aerodynamic boundary conditions. The shape morphing was achieved which targeted radial expansion of the ducts where majority of the duct sections are morphed to a shape that is within 1% of the duct diameter of the targeted optimum shape.