Executive Summary : | The proposal aims to investigate the unsteady effects of ground proximity on the dynamics of fixed-wing and rotary-wing aircraft. The study will focus on two cases of energy-efficient flight for enhanced endurance: dynamic soaring of fixed-wing aircraft and operation of rotorcraft in low-density atmospheres. The project will involve simulation of fixed-wing aircraft dynamics using an unsteady vortex lattice method based solver, study of rotorcraft transient response in the presence of ground using a dynamic inflow and free-wake model, and experimental study of unsteady effects on rotorcraft in low-density atmospheres. The study will use an unsteady vortex lattice method (UVLM) solver to capture the aerodynamic forces and moments acting on aircraft or rotor, including the dynamic effect of the ground. Dynamic soaring, a specific flight manoeuvre exhibited by albatross, will be simulated, involving continuous variation of control inputs and aircraft states. This study will be of significance in developing a model-based controller and contributing to research on wing-in-ground effect-based designs. Rotorcraft operating at very low densities is a challenge, and ground effect for flight is an attractive option for missions to explore other planet surfaces. The study will involve numerical investigations using dynamic inflow and free-wake code coupled with a rotor dynamics model and experimental investigation of rotor aerodynamics and dynamics in a low-density atmosphere. |