Mass prediction models for air cargo challenge aircraft

Abstract

AbstractDesign/Build/Fly competitions are attracting increased interest in the training of aerospace engineers at academic level worldwide. These competitions entail fundamental activities in aircraft design, optimization and manufacturing which foster student knowledge not possible in classical academic activities. Over the years, the competitiveness of these contests has increased due to the ever-increasing performance that the aircraft exhibit in the flight event. Mass prediction models, specific for competitions such as Air Cargo Challenge (ACC), are presented in this paper. These models are divided into two development methods: statistical and structure-based equations.The statistical mass models are developed based on data collected from past ACC editions where model accuracy is mainly dependent on the amount of data available. Three models are derived, one containing all available aircraft and two more obtained by dividing the aircraft into balsa- or composite-dominated structures.Using the structure-based equations method, where the amount of material required to withstand the stresses that the airplane is subjected to is determined, a model is developed for each one of the three considered wing structural concepts, namely two-cell Carbon-Fibre-Reinforced Plastic (CFRP), CFRP D-box and CFRP tube spar. The tail boom component equation is created independently, while the remaining components masses are determined from coefficients based on geometric characteristics and the computed wing or total masses. The average error associated with these models is inferior to 2% for the total mass.The results obtained from the application to the considered study cases are also presented, and the validity, accuracy, and application in terms of the design phase for each method are discussed.