Aerodynamic Design of Blended Wing-Body and Lifting-Fuselage Aircraft

Abstract

High-fidelity aerodynamic shape optimization based on the Reynolds-averaged Navier-Stokes equations is used to optimize the aerodynamic performance of conventional and blended wing-body (BWB) aircraft for a range of aircraft sizes from regional to wide-body classes. Trim-constrained drag minimization is performed, with optimized conventional tube-and-wing (CTW) designs serving as performance references. First, a set of 'classically' shaped BWB configurations are optimized across the range of classes. The classically shaped regional and narrow-body-class BWBs offer only a marginal fuel-burn benefit relative to the equivalent conventional designs. The wide-body-class BWB offers up to 10.9% lower fuel-burn than the equivalent CTW. Exploratory optimizations with significant geometric freedom are then performed, resulting in a set of novel shapes with a more slender lifting fuselage and distinct wings. Based on these exploratory results, new lifting-fuselage configurations (LFCs) are designed. The slenderness of the LFC fuselage decreases with aircraft size, such that, for the largest class, the LFC reduces to a classical BWB shape. Due to their lower weight and higher aerodynamic efficiency, the LFC designs burn 6.1% and 9.7% less fuel in cruise than the equivalent CTWs for the regional and narrow-body classes, respectively. In addition, the LFCs are more aerodynamically efficient and burn less fuel than the BWBs. Additional optimizations were performed to determine the aerodynamically optimal cruise altitude of all of the aircraft. Due to their lower wing loading, the resulting increase in cruise altitude is most beneficial for the BWBs, such that the regional and narrow-body-class BWBs burn up to 5.5% less fuel than the CTWs. The LFCs offer up to a 10.3% fuel-burn reduction relative to the CTWs when at their optimal altitude.

Conceptual Design and Evaluation of Blended-Wing Body Aircraft

“…This would have an impact on the cruise profile of the aircraft, requiring more increases in altitude (step climbs) to remain at an efficient C L . This effect could be reduced by finding a more optimum initial cruise altitude, 1,43 which is left for further research.…”

“…The aspect ratio is chosen considerably lower for the BWB compared to than the TAW aircraft, similar to other BWB design studies. 3,12,25,43 The chosen aspect ratios have been tweaked to achieve good results in terms of wing span for airport gate limits, climb gradients and the resulting sizing of the fuselage and outer wing combination.…”

Lift and Drag of Non-conventional Wings at Subsonic Speeds and Zero Angle of Attack - An Experimental Investigation

“…Reist and Zingg [5] studied the blended wing body (BWB) which has a nonconventional configuration of combining the airplane body and wings as one component. This configuration was proven to have high potential in improving aerodynamic performance on larger airplanes.…”

“…The experimental was conducted at Reynolds number, Re = 1×10 5 . To achieve this Reynolds number, the velocity of air flow was calculated to be 11.79 m/s.…”

Numerical simulation for the differences between FTN/WPN engine models aerodynamic influence on BWB300 airframe

“…The Blended Wing Body is a revolutionary concept offering advantages of aerodynamic performance and fuel economy (Larkin & Coates, 2017;Reist & Zingg, 2016). Engine installation on conventional transport is often mounted under the wing (Oliveira, Trapp, & Puppin-Macedo, 2003;Stankowski, MacManus, Robinson, & Sheaf, 2017).…”