The Development of an Inertia Estimation Method to Support Handling Quality Assessment

Abstract

Mass of an aircraft as well as distribution of it along the body are important concerns during the design process due to their significant influence on performance and inertia. Inertia of an aircraft has to be known in order to examine the handling qualities, which have a large effect on aircraft’s design. However, due to the smeared properties of the structure and many of the system architectures, the calculation of inertia is nontrivial. Moreover, non-traditional aircraft designs might not be able to rely on existing empirical calculations. Hence, the main objective of this project is developing a rapid geometry based inertia estimation applicable for any aircraft configuration. In order to have a design sensitive method, the aircraft is divided into three categories namely bodies of revolution, lifting surfaces and point masses where components are grouped according to their shapes. Fuselage and nacelle components are categorized as bodies of revolution and their inertias are estimated in a similar fashion. Lifting surfaces include main wing, horizontal and vertical stabilizers. The rest of the aircraft components are assumed to be point masses. The implemented method is used in conventional, canard and three surface configurations. In order to examine their handling qualities, control and stability derivatives are also needed which is why a calculation method is implemented. Calculated inertia and derivatives of each configuration are used as input in a flight mechanics toolbox. Hence, the influence of configuration on aircraft’s inertia and consequently on aircraft behavior has been able to examined in a rapid process.