Blended wing body lateral-directional stability investigation using 6DOF simulation

Abstract

Presently at the Von Karman Institute for Fluid Dynamics, a comprehensive research investigation is being performed on the lateral-directional stability characteristics of a business jet class blended wing body. This paper presents an innovative MATLAB-based methodology using a multi-disciplinary design and optimization code written by the author, which combines various flow solvers, structural solvers, and aircraft design equations, to gain a comprehensive understanding of the overall vehicle performance while simultaneously creating a database for six-degrees-of-freedom (6DOF) flight simulation. Initial validation of the design was achieved through the Monte Carlo analysis of a 6DOF flight simulator, testing the take-off and landing flight regimes where the blended wing body is prone stall and departure due to asymmetric flow over the wing. Differential control effectors on the bottom of the wing, called “belly-flaps,” are investigated for lateral-directional control. Initial test results show that optimal span is 20% b/2, chord 20% [Formula: see text], located at 62% croot, with zero separation from vehicle centerline.

Conceptual Design and Evaluation of Blended-Wing Body Aircraft

“…23 AVL's performance on BWB aircraft in terms of induced drag has also been investigated and used in many studies. 2,14,39,40 The use of AVL also supports the research goals of comparing TAW and BWB using similar methods. The outer wing and fuselage are modelled using the sections and airfoils already defined.…”

“…Roysdon found moment coefficients of one order of magnitude lower (less negative) while also using AVL. 40 Qin et al, on the other hand, found values in the range of C M = [−0.074 : −0.090] in cruise, for initial unoptimized designs using Euler and Navier-Stokes CFD solutions. 42 These values are much closer to the values achieved by the Initiator.…”

On the maximisation of control power in low-speed flight

“…For example, the trailing-edge surfaces may consist of a body flap inner and outer flaps and ailerons that may be used for lift, pitch or roll control. The present work extends existing knowledge on the subject in two directions: (i) on theoretical side (10)(11)(12)(13) by allowing for the deflections of multiple control surfaces, that gives more options to obtain the desired forces or moments with less risk of flow separation or aeroelastic effects; (ii) on the application side (14)(15)(16)(17) by considering not only minimum drag but also maximum drag (e.g. for fast descent) and maximum control moments for emergencies, such an engine-out condition.…”

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

“…The same BWB configurations were further studied by means of piloted simulation using a motion base simulator by Peterson and Grant [30]. Roysdon and Khalid [31] studied the lateral-directional stability of a small business jet BWB using computational fluid dynamics and flight simulation and found that good controllability can be achieved. They also used a simple DC control allocation method and did not address trim drag aspects.…”