Generation of Aerodynamics Via Physics-Based Virtual Flight Simulations

摘要

A method to efficiently generate a complete aerodynamic description for projectile flight dynamic modeling is described. At the core of the method is an unsteady, time accurate computational fluid dynamics simulation that is tightly coupled to a rigid projectile flight dynamic simulation. This coupled multidisciplinary technique allows 'virtual fly-out' of projectiles on supercomputers, predicts the fight path of a projectile and all the associated unsteady free-flight aerodynamics in an integrated manner, and offers a new approach for generating a complete aerodynamic description consisting of both static and dynamic aerodynamic coefficients. A set of short time snippets of simulated projectile motion at different Mach numbers is computed and employed as baseline data. For each time snippet, aerodynamic forces and moments and the full rigid body state vector of the projectile are known. With time synchronized air loads and state vector information, aerodynamic coefficients can be estimated with a simple fitting procedure. By inspecting the condition number of the fitting matrix, it is straight forward to assess the suitability of the time history data to predict a selected set of aerodynamic coefficients. The technique is exercised on a fin stabilized projectile with promising results.