Experimental Investigation Into the Feasibility of Measuring Static and Dynamic Aerodynamic Derivatives in the DSTO Water Tunnel.

摘要

This report gives details of an experimental research investigation carried out in the DSTO water tunnel to see whether it is feasible to measure meaningful aircraft static and dynamic aerodynamic derivatives. These derivatives represent the aerodynamic damping and coupling forces and moments on an aircraft and are used in its equations of motion. A Standard Dynamics Model (SDM), a simplified fighter aircraft configuration, was used for the tests. The SDM was subjected to forced small sinusoidal pitching oscillations and derivatives were computed from measured model loads, angles of attack, reduced frequency of oscillation and aircraft geometrical parameters. The derivatives obtained in the water tunnel were compared with corresponding published data obtained using SDMs in wind tunnels. Although wind tunnels are the preferred option to obtain derivatives, it was found that it is feasible to use a water tunnel to obtain approximate derivatives, at least for models having SDM-type geometries, especially if derivatives are required quickly and cheaply.