The first step of advanced design is obtaining a thorough understanding of top level requirements and the environment in which the aircraft will be operating. The early design stage is also characterized by making sketches of one or more tentative general arrangements and a first estimation of design weights: payload, empty weight, fuel weight, maximum take‐off and landing weight. This chapter discusses the unity equation and demonstrates how a realistic prediction can be made of aerodynamic and propulsive efficiencies in the initial cruise condition. It is shown that the aerodynamic efficiency in cruising flight can be obtained by using several geometric parameters as input. In combination with basic engine characteristics, this leads to initial prediction of the range parameter for cruising, an essential figure of merit for computing the mission fuel. This chapter finally discusses the importance of the energy efficiency for reducing fuel costs and engine emissions.
Early Conceptual Design
Advanced Aircraft Design ; 31-58
2013-06-21
28 pages
Article/Chapter (Book)
Electronic Resource
English