Conceptual Configuration of a Blended Wing Body Landing Gear System

Abstract

The Blended-Wing-Body (BWB) is a revolutionary concept for commercial aircraft. In the past years a great deal of research has been performed for the design of BWB configurations. Various engineering disciplines have been considered and resulted in many design suggestions, e.g. proposed wing planform, proposed distributed propulsion for the blended wing body, etc. On the other hand, there have been few explorations in the field of the dynamical behavior of the aircraft focusing on ground manoeuvres. Similary, few proposals for BWB landing gear configurations have been suggested. Landing gear design involves the analysis of complex dynamical systems and also encompasses many engineering disciplines such as structural mechanics and weights. The conventional landing gear design process has proven to lead to satisfactory design in most cases. However, if a novel aircraft concept such as BWB is concerned where no comparable experience is available, the classical approaches might not be applicable. As the landing gear design process involves various engineering disciplines, this provides a rich opportunity for the implementation of the Multidisciplinary Design Optimization (MDO) process. An essential element needed to be included in the newly required process is the addressing of the unknown BWB ground dynamical behavior. Multibody Simulation (MBS) with its capability of the analysis of complex system dynamics in the respect of e.g. dynamic behavior and dynamic loads determination can serve as the analysis tool for this purpose. This paper thus presents a new, improved landing gear conceptual design process with the connection between MBS, other Computational Aided Engineering (CAE) tools, and an optimizer. In this paper three different configurations, with three different numbers of the main landing gear, MLG, of 4, 6 and 12 are modelled, analysed and optimized. Two conflicting weight criteria of each configuration, the landing gear system weight and the total system, i.e. the support structure plus the landing gear system weight, are investigated. The results show that the newly integrated design process is an efficient tool for assisting in the selection of the BWB landing gear conceptual design. For the case analysed in the paper, a 6 MLG design proved to be the best compromise. However, the optimum number of MLG might vary depending on aircraft weight and dominant load cases.