Blended Wing Body Propulsion System Design
08 Oct 2017-International Journal of Aviation, Aeronautics, and Aerospace (Embry-Riddle Aeronautical University)-Vol. 4, Iss: 4, pp 6
About: This article is published in International Journal of Aviation, Aeronautics, and Aerospace.The article was published on 2017-10-08 and is currently open access. It has received 9 citations till now. The article focuses on the topics: Propulsion.
Citations
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28 Apr 2020
TL;DR: This study aims to create a novel BWB design to test its flying and handling qualities using an engineering flight simulator and to identify potential design solutions which will enhance its controllability and manoeuvrability characteristics.
Abstract: The Blended Wing Body (BWB) configuration is considered to have the potential of providing significant advantages when compared to conventional aircraft designs. At the same time, numerous studies have reported that technical challenges exist in many areas of its design, including stability and control. This study aims to create a novel BWB design to test its flying and handling qualities using an engineering flight simulator and as such, to identify potential design solutions which will enhance its controllability and manoeuvrability characteristics. This aircraft is aimed toward the commercial sector with a range of 3000 nautical miles, carrying 200 passengers. The BWB design was flight tested at an engineering flight simulator to first determine its static stability through a standard commercial mission profile, and then to determine its dynamic stability characteristics through standard dynamic modes. Its flying qualities suggested its stability with a static margin of 8.652% of the mean aerodynamic chord (MAC) and consistent response from the pilot input. In addition, the aircraft achieved a maximum lift-to-drag ratio of 28.1; a maximum range of 4,581 nautical miles; zero-lift drag of 0.005; while meeting all the requirements of the dynamic modes.
13 citations
26 Feb 2021
TL;DR: In this article, the Lagrange multipliers are used to solve control optimization problems in a blended-wing-body with multiple control surfaces, e.g., to minimize cruise drag due to pitch trim, or to maximize pitching moment at low speed in an engine-out condition.
Abstract: A blended-wing-body is an example of an aircraft configuration with multiple control surfaces. The most effective use of these control surfaces, e.g. to minimize cruise drag due to pitch trim, or to maximize pitching moment at low speed in an engine-out condition, leads to optimization problems. This kind of control optimization problems can be addressed by the method of Lagrange multipliers; this allows for multiple constraints, e.g. constant lift, pitching or other moments, each associated with one multiplier. The value of the multiplier is a measure of the severity of the constraint, e.g. the drag penalty of imposing pitch trim at constant lift.
11 citations
TL;DR: A systems theory based hybrid model is established to integrate the physical system reliability analysis techniques with the system dynamics method for illustrating the multiple risk interactions of the demonstrator flight test involving organizational, human resource and technical system factors.
5 citations
01 Mar 2021
TL;DR: In this article, the coupling of the longitudinal and lateral stability modes of an aeroplane is considered in two cases: (i) weak coupling, when the changes in the frequency and damping of the phugoid, short period, dutch roll, and helical modes are small.
Abstract: The coupling of the longitudinal and lateral stability modes of an aeroplane is considered in two cases: (i) weak coupling, when the changes in the frequency and damping of the phugoid, short period, dutch roll, and helical modes are small, i.e., the square of the deviation is negligible compared to the square of the uncoupled value; (ii) strong coupling, when the coupled values may differ significantly from the uncoupled values. This allows a comparison of three values for the frequency and damping of each mode: (i) exact, i.e., fully coupled; (ii) with the approximation of weak coupling; (iii) with the assumption of decoupling. The comparison of these three values allows an assessment of the importance of coupling effects. The method is applied to two flying wing designs, concerning all modes in a total of eighteen flight conditions. It turns out that lateral-longitudinal coupling is small in all cases, and thus classical handling qualities criteria can be applied. The handling qualities are considered for all modes, namely the phugoid, short period, dutch roll, spiral, and roll modes. Additional focus is given to the pitch axis, considering the control anticipation parameter (CAP). The latter relates to the two kinds of manouever points, where damping vanishes, that are calculated for minimum speed, take-off, and initial and final cruise conditions. The conclusion compares two flying wings designs (the “long narrow” and “short wide” fuselage concepts) not only from the point of view of flight stability, but also from other viewpoints.
5 citations
TL;DR: In this paper, a computational fluid dynamics analysis of the wing-winglet configuration based on the ONERA M6 airfoil on drag reduction for different attack angles at Mach 0.84 was performed using analysis of systems Fluent.
Abstract:
Purpose
Winglets play a major role in saving fuel costs because they reduce the lift-induced drag formed at the wingtips. The purpose of this paper is to obtain the best orientation of the winglet for the Office National d’Etudes et de Recherches Aérospatiales (ONERA) M6 wing at Mach number 0.84 in terms of lift to drag ratio.
Design/methodology/approach
A computational fluid dynamics analysis of the wing-winglet configuration based on the ONERA M6 airfoil on drag reduction for different attack angles at Mach 0.84 was performed using analysis of systems Fluent. First, the best values of cant and sweep angles in terms of aerodynamic performance were selected by performing simulations. The analysis included cant angle values of 30°, 40°, 45°, 55°, 60°, 70° and 75°, while for the sweep angles 35°, 45°, 55°, 65° and 75° angles were used. The aerodynamic performance was measured in terms of the obtained lift to drag ratios.
Findings
The results showed that slight alternations in the winglet configuration can improve aerodynamic performance for various attack angles. The best lift to drag ratio for the winglet was achieved at a cant angle of 30° and a sweep angle of 65°, which caused a 5.33% increase in the lift to drag ratio. The toe-out angle winglets as compared to the toe-in angles caused the lift to drag ratio to increase because of more attached flow at its surface. The maximum value of the lift to drag ratio was obtained with a toe-out angle (−5°) at an angle of attack 3° which was 2.53% greater than the zero-toed angle winglet.
Originality/value
This work is relatively unique because the cant, sweep and toe angles were analyzed altogether and led to a significant reduction in drag as compared to wing without winglet. The wing model was compared with the results provided by National Aeronautics and Space Administration so this validated the simulation for different wing-winglet configurations.
4 citations
References
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TL;DR: In this article, the effects of spanwise distribution on the aircraft aerodynamic efficiency were studied through an inverse twist design approach, combining both a low fidelity panel method and a high-fidelity Reynolds-averaged Navier-Stokes solution method.
210 citations
"Blended Wing Body Propulsion System..." refers methods in this paper
...Qin et al. (2004) used a NACA 0012 airfoil to act as the airfoil sections of the winglet, suggesting design techniques are similar to those used in tube and wing aircraft....
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...Using a BWB suggests a lift to drag improvement of about 20% over comparable tube and wing designs (Potsdam, Page, & Liebeck, 1997; Qin et al., 2004), in addition to greater fuel and cost savings associated with further decreased weight....
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...Qin et al. (2004) also found a significant improvement in the lift to drag ratio over the baseline lift distribution by utilizing an averaged distribution....
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Book•
01 Jan 1989
TL;DR: In this paper, aeroelasticite Reference Record created on 2005-11-18, modified on 2016-08-08 is used for aerodynamic design of turboreacteurs.
Abstract: Keywords: aerodynamique ; instationnaire ; conception ; turboreacteurs ; systemes : thermiques ; propulsion ; aeroelasticite Reference Record created on 2005-11-18, modified on 2016-08-08
80 citations
23 Jun 1997
77 citations
"Blended Wing Body Propulsion System..." refers background in this paper
...The large payload of a prospective BWB design requires centerbody airfoils to have thickness to chord ratios near 17-18, far greater than those seen on supercritical airfoils on today’s commercial aircraft (Liebeck, 2004; Potsdam et al., 1997)....
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...For a BWB, many conceptual designs utilize a set of aft mounted engines on pylons, or integrated into the wing (for example: Liebeck, 2004; Nickol & McCullers, 2009; Potsdam et al., 1997; Roman et al., 2000)....
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...The maximum lift to drag ratio is directly proportional to the square root of the wetted aspect ratio (Potsdam et al., 1997)....
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05 Jan 2009
TL;DR: In this paper, a hybrid wing body (HWB) sizing and analysis capability was developed to estimate the fuel burn potential for an HWB concept, and identify associated technology requirements.
Abstract: The objective of this study was to develop a hybrid wing body (HWB) sizing and analysis capability, apply that capability to estimate the fuel burn potential for an HWB concept, and identify associated technology requirements An advanced tube with wings concept was also developed for comparison purposes NASA s Flight Optimization System (FLOPS) conceptual aircraft sizing and synthesis software was modified to enable the sizing and analysis of HWB concepts The noncircular pressurized centerbody of the HWB concept was modeled, and several options were created for defining the outboard wing sections Weight and drag estimation routines were modified to accommodate the unique aspects of an HWB configuration The resulting capability was then utilized to model a proprietary Boeing blended wing body (BWB) concept for comparison purposes FLOPS predicted approximately a 15 percent greater drag, mainly caused by differences in compressibility drag estimation, and approximately a 5 percent greater takeoff gross weight, mainly caused by the additional fuel required, as compared with the Boeing data Next, a 777-like reference vehicle was modeled in FLOPS and calibrated to published Boeing performance data; the same mission definition was used to size an HWB in FLOPS Advanced airframe and propulsion technology assumptions were applied to the HWB to develop an estimate for potential fuel burn savings from such a concept The same technology assumptions, where applicable, were then applied to an advanced tube-with-wings concept The HWB concept had a 39 percent lower block fuel burn than the reference vehicle and a 12 percent lower block fuel burn than the advanced tube-with-wings configuration However, this fuel burn advantage is partially derived from assuming the high-risk technology of embedded engines with boundary-layer-ingesting inlets The HWB concept does have the potential for significantly reduced noise as a result of the shielding advantages that are inherent with an over-body engine installation
75 citations
"Blended Wing Body Propulsion System..." refers background in this paper
...For a BWB, many conceptual designs utilize a set of aft mounted engines on pylons, or integrated into the wing (for example: Liebeck, 2004; Nickol & McCullers, 2009; Potsdam et al., 1997; Roman et al., 2000)....
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14 Aug 2000
TL;DR: The aerodynamic design of a Blended-Wing-Body (BWB) aircraft is substantially more complicated than that of a conventional wing as mentioned in this paper, and a detailed overview of unique design problems faced by the BWB wing designer is provided.
Abstract: The aerodynamic design of a Blended-Wing-Body (BWB) aircraft is substantially more complicated than that of a conventional wing. This paper provides an overview of unique design problems faced by the BWB wing designer, discusses the applicability of Navier-Stokes analysis, and summarizes the progress made to date. BACKGROUND Development of the Blended-Wing-Body (BWB) concept began with a NASA sponsored study to create a new, more efficient, configuration for subsonic transport aircraft. The initial BWB approach to the challenge sought to improve the aerodynamics by increasing wetted aspect ratio (b2/Swet). For the payload-range specification of 800 passengers and 7000 nautical miles, the BWBconcept evolved from the streamlined-disk plus wing sketch shown in Figure 1, where it is compared with a conventional "tube and wing" configuration.
67 citations
"Blended Wing Body Propulsion System..." refers background in this paper
...Roman et al. (2000) further stated that traditional supercritical airfoils should be used on the outer sections of the wing, while the center should use a reflexed airfoil in order to provide it with pitch trim, compensating for the lack of the tail....
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...While winglets do provide the same reduction in induced drag seen in tube and wing aircraft, winglets can also act as vertical stabilizers in tailless BWB designs (Roman et al., 2000)....
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...For a BWB, many conceptual designs utilize a set of aft mounted engines on pylons, or integrated into the wing (for example: Liebeck, 2004; Nickol & McCullers, 2009; Potsdam et al., 1997; Roman et al., 2000)....
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...According to Roman, Allen, and Liebeck (2000), the BWB has a 33% increase in wetted aspect ratio over a comparable tube and wing aircraft, in addition to other aerodynamic benefits regarding the span efficiency factor and wave drag....
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