Fuel management system for cruise performance optimization on a large blended wing body airliner

Abstract

Blended Wing Body (BWB) aircraft con¦gurations have been proposed for signi¦cant fuel e©ciency improvement on commercial transport. In order to §y with the optimum lift-to-drag ratio throughout most of the mission, an adaptation of the center of gravity (CG) by fuel redistribution is proposed. The most aft location of the CG which still is controllable is mainly limited by actuator bandwidth whereas the front CG location is limited by control authority of the trailing edge control surfaces. This paper provides an optimization of the CG position with regards to minimization of fuel consumption. Layout of the fuel tank system is illustrated. Moreover, active stabilization of faulty CG positions is discussed.

The impact of control allocation on trim drag of blended wing body aircraft

“…As indicated in Section 1, various studies have proposed to use fuel trim on BWB aircraft [25,27]. This solution can be combined in a straightforward manner with the control allocation methods proposed in the current study.…”

“…It was determined that the cg position and corresponding static stability has a large influence on the required thrust level in trim [24]. Therefore a fuel trim system was proposed [25] similar to the solution used in the Concorde [26]. However, the effect of control allocation on trim drag was not investigated in these studies.…”

On the Extrapolation of Stability Derivatives to Combined Changes in Airspeed and Angles of Attack and Sideslip

“…The starting point (26) is perhaps the main simplifying assumption in the derivation of extrapolation factors for stability derivatives. It reflects the fact that the main dependence of aerodynamic forces and moments is on the square of the airspeed for the potential flow of an inviscid fluid [45,46].…”

“…The extrapolation of stability derivatives is illustrated for a V-tailed single-aisle jetliner design but can be applied not only to V-tailed aircraft [11][12][13][14][15] but to other configurations [16][17][18][19], such as blended-wing bodies [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] and joined wings [40,41], that can have large number of control surfaces changing their geometry. The effort of determination of each stability derivative for a given airspeed could be reduced from one full table (combinations of the AoA and AoS) to (a) a list (dependence on one extrapolated to the other) or (b) a single value (extrapolation from given AoA and AoS).…”

Αριθμητική Επίλυση Προβλημάτων Αεροδυναμικής-Αεροελαστικότητας Σε Επεξεργαστές Καρτών Γραφικών

“…Στις εργασίες [247,248] πραγματοποιήθηκε ο σχεδιασμός των δομικών χαρακτηριστικών ενός αεροσκάφους τύπου BWB με στόχο την ελαχιστοποίηση του βάρους απογείωσης. Αντικείμενο της εργασίας [249] αποτέλεσε η εύρεση της βέλτιστης θέσης του κέντρου βάρους αεροσκάφους τύπου BWB, κατανέμοντας κατάλληλα τα καύσιμά του, με στόχο την αύξηση της απόδοσης του αεροσκάφους κατά τη διάρκεια ευθείας πτήσης.…”