Aerospace Systems Efficiency Improvements for Legacy Aircraft

ABSTRACT: The expense in operating legacy aircraft is reduced if the aerodynamic performance can be improved. Many of these aircraft were designed before modern prediction methods and flow controls were available and it is probable that operating costs could be reduced if recent advances were used. Since a complete redesign is out of the question, the issue is whether relatively minor, and inexpensive, changes to the airframe might be advantageous. Since there might be a large range of design options that could affect the performance in an operational setting, the exercise is akin to conceptual design; many design options must be ranked. Any aerodynamic prediction must be computationally fast and accurate and, while classic panel methods meet these criteria, they are restricted to situations where potential flow is valid. This prevents application to many flow controls which may initiate a rotational, non-isentropic flow, possibly with energy addition. A recently developed theory allows the Navier Stoke equations to be written in a form similar to the classic panel method formulation. The proposed research will use this formulation to develop an extended panel method that can be used to evaluate the effectiveness of flow control and other strategies to improve operational performance. BENEFIT: A successful research program will lead to the development of an advanced panel method that can represent much more complex aerodynamics, including flow controls, that are beyond the capabilities of current formulations. The resulting software will be of great benefit to the government (especially the Air Force) and all industries that need rapid estimation of aerodynamic forces; application include aircraft, ships, submarines, automobiles, wind energy.