A Fast Aerodynamic Procedure for a Complete Aircraft Design Using the Know Airfoil Characteristics

The performance and flight characteristics of an aircraft are markedly affected by the aerodynamic design, which can be done making use of various tools such as wind tunnel tests and computer simulations. Despite the fact that wind tunnel testing permits great trustworthiness of results, they are still slow and costly procedures. On the other hand, computational methods allow for faster and lower budget analysis. For the conception and the initial phase of an aircraft design, where it is necessary to evaluate a great variety of wings and lifting surfaces configurations, it is desirable to have a method able to determine the main aerodynamic characteristics, such as drag and lift, quickly. In more advanced phases of the design the interest is in obtaining results which shows a more detailed flow around the aircraft. This paper describes a fast method with good results for the calculation of aerodynamic characteristics of a complete aircraft where a simple three-dimensional numeric model is corrected based on the characteristics of bi-dimensional flow around the aerodynamic profile experimentally obtained, with an option of adding to the method a free wake model and measurement of induced drag through the Momentum variation. This procedure results in a non linear method capable of predicting lift, induced drag, parasite drag, aerodynamic moments both in linear regions as well as stall regions in the lift curve of a complete aircraft, including effects due to yaw, pitch and roll, and the influence between surfaces. This paper presents some results obtained with this procedure and compares them to experimental results.