Effects of stability margin and thrust specific fuel consumption constrains on multi-disciplinary optimization for blended-wing-body design

Blended-Wing-Body (BWB) configuration, as an innovative transport concept, has become a worldwide research focus in the field of civil transports development. Relative to the conventional Tube-And-Wing (TAW) configuration, the BWB shows integrated benefits and serves as a most promising candidate for future “green aviation”. The objective of the present work is to figure out the effects of the stability margin and Thrust Specific Fuel Consumption (TSFC) on the BWB design in the framework of Multi-Disciplinary Optimization (MDO). A physically-based platform was promoted to study the effect static stability margin and engine technology level. Low-order physically based models are applied to the evaluation of the weight and the aerodynamic performance. The modules and methods are illustrated in detail, and the validation of the methods shows feasibility and confidence for the conceptual design of BWB aircrafts. In order to find out the relation between planform changes and the selection of stability and engine technology level, two sets of optimizations are conducted separately. The study proves that these two factors have dominant effects towards the optimized BWB designs in both aerodynamic shapes, weight distribution, which needs to be considered during the MDO design process. A balance diagram analysis is applied to find out a reasonable static stability margin range. It can be concluded that a recommended stability margin of a practical BWB commercial aircraft can be half of that of a conventional TAW design.