scholarly journals Multi-Fidelity Design Optimization of a Long-Range Blended Wing Body Aircraft with New Airframe Technologies

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 87
Author(s):  
Stanislav Karpuk ◽  
Yaolong Liu ◽  
Ali Elham
Keyword(s):  
Long Range ◽  
New Technologies ◽  
Active Flow Control ◽  
Preliminary Investigation ◽  
Aircraft Design ◽  
Fuel Burn ◽  
Aircraft Fuel ◽  
Computational Fluid Dynamics Cfd ◽  
Blended Wing Body ◽  
Active Flow

The German Cluster of Excellence SE²A (Sustainable and Energy Efficient Aviation) is established in order to investigate the influence of game-changing technologies on the energy efficiency of future transport aircraft. In this paper, the preliminary investigation of the four game-changing technologies active flow control, active load alleviation, boundary layer ingestion, and novel materials and structure concepts on the performance of a long-range Blended Wing Body (BWB) aircraft is presented. The BWB that was equipped with the mentioned technologies was designed and optimized using the multi-fidelity aircraft design code SUAVE with a connection to the Computational Fluid Dynamics (CFD) code SU2. The conceptual design of the BWB aircraft is performed within the SUAVE framework, where the influence of the new technologies is investigated. In the second step, the initially designed BWB aircraft is improved by an aerodynamic shape optimization while using the SU2 CFD code. In the third step, the performance of the optimized aircraft is evaluated again using the SUAVE code. The results showed more than 60% reduction in the aircraft fuel burn when compared to the Boeing 777.

scholarly journals Numerical study on the steady suction active flow control of hydrofoil in the profile of the blended-wing-body underwater glider

2021 ◽  
Vol 39 (4) ◽  
pp. 801-809
Author(s):  
Xiaoxu Du ◽  
Lianying Zhang
Keyword(s):  
Flow Control ◽  
Numerical Study ◽  
Active Flow Control ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Hydrodynamic Performance ◽  
Flow State ◽  
Underwater Glider ◽  
Blended Wing Body ◽  
Active Flow

The hydrodynamic performance of the blended-wing-body underwater glider can be improved by opening a hole on the surface and applying the steady suction active flow control. In order to explore the influence law and mechanism of the steady suction active flow control on the lift and drag performance of the hydrofoil, which is the profile of the blended-wing-body underwater glider, based on the computational fluid dynamics (CFD) method and SST k-ω turbulence model, the steady suction active flow control of hydrofoil under different conditions is studied, which include three suction factors: suction angle, suction position and suction ratio, as well as three different flow states: no stall, critical stall and over stall. Then the influence mechanism in over stall flow state is further analyzed. The results show that the flow separation state of NACA0015 hydrofoil can be effectively restrained and the flow field distribution around it can be improved by a reasonable steady suction, so as to the lift-drag performance of NACA0015 hydrofoil is improved. The effect of increasing lift and reducing drag of steady suction is best at 90° suction angle and symmetrical about 90° suction angle, and it is better when the steady suction position is closer to the leading edge of the hydrofoil. In addition, with the increase of the suction ratio, the influence of steady suction on the lift coefficient and drag coefficient of hydrofoil is greater.

Aerodynamic Characteristics of a Blended-Wing-Body Aircraft With A Serpentine Inlet Using Flow Control Techniques

2021 ◽  
Author(s):  
Min-Sik Youn ◽  
Youn-Jea Kim
Keyword(s):  
Flow Control ◽  
Flow Separation ◽  
High Efficiency ◽  
Active Flow Control ◽  
Quantitative Measure ◽  
Aerodynamic Characteristics ◽  
Interface Plane ◽  
Flow Distortion ◽  
Blended Wing Body ◽  
Active Flow

Abstract Demands of a modern aircraft regarding its aerodynamic performance and high efficiency are ever-growing. An S-shaped inlet, as known as a serpentine duct, plays a significant role in increasing fuel efficiency. Recently, the serpentine duct is commonly employed for military aircraft to block the front of the jet engine from radar. However, delivering a non-uniformly distorted flow to the engine face (aerodynamic interface plane, AIP) though a serpentine duct is inevitable due to the existence of flow separation and swirl flow in the duct. The effect of distortion is to cause the engine compressor to surge; thus, it may impact on the life-cycle of aircraft engine. In this study, aerodynamic characteristics of a serpentine duct mounted on a blended-wing-body (BWB) aircraft was thoroughly investigated to determine where and how the vortex flow was generated. In particular, both passive and active flow control were implemented at a place where the flow separation was occurred to minimize the flow distortion rate in the duct. The passive and active flow control systems were used with vortex generator (VG) vanes and air suctions, respectively. A pair of VG s have been made as a set, and 6 sets of VG in the serpentine duct. For the active flow control, 19 air suctions have been implemented. Both flow control devices have been placed in three different locations. To evaluate the performance of flow control system, it is necessary to quantify the flow uniformity at the AIP. Therefore, coefficient of distortion, DC(60) was used as the quantitative measure of distortion. Also, change in DC(60) value while the BWB aircraft is maneuvering phase was analyzed.

Investigation of a Fuel Cell-Powered Blended Wing Body Airliner With Boundary Layer Re-Energization

2002 ◽  
Author(s):  
Vassilios A. Pachidas ◽  
Riti Singh
Keyword(s):  
Boundary Layer ◽  
Fuel Cell ◽  
High Speed ◽  
Preliminary Investigation ◽  
Specific Power ◽  
Fuel Burn ◽  
High Specific Power ◽  
Blended Wing Body ◽  
Center Body

The following study was undertaken on the assumption that hydrocarbon-based fuels may not be acceptable in the very long term, because of environmental concerns. A possible future fuel is hydrogen, and this study explores a novel proposition for a civil airliner using hydrogen fuel. The technical challenges of this preliminary investigation were: a) the integration of an electric power plant (Fuel Cell) into a Blended Wing Body (BWB) aircraft, and b) to investigate the possibility of reducing the aircraft’s profile drag by boundary layer re-energization. For the re-energization of the boundary layer and for propulsion during cruise, the study considered High-Speed/High Specific Power (HS/HSP) motors, situated at the trailing edge (TE) of the center body, driving fans. Re-energizing the boundary layer of the center body, would reduce the profile drag of the aircraft and hence, the total fuel burn. The take-off requirements of the aircraft were met, by high by-pass ratio (BPR) turbofan lift engines, operating on hydrogen, for a V/STOL (Pachidis, 2000b).

scholarly journals Deep Reinforcement Learning for Active Flow Control around a Circular Cylinder Using Unsteady-mode Plasma Actuators

2020 ◽  
Author(s):  
Mohamed Elhawary
Keyword(s):  
Fluid Dynamics ◽  
Reinforcement Learning ◽  
Drag Reduction ◽  
Flow Control ◽  
Control Strategies ◽  
Active Flow Control ◽  
Plasma Actuators ◽  
Burst Frequency ◽  
Computational Fluid Dynamics Cfd ◽  
Active Flow

Deep reinforcement learning (DRL) algorithms are rapidly making inroads into fluid mechanics, following the remarkable achievements of these techniques in a wide range of science and engineering applications. In this paper, a deep reinforcement learning (DRL) agent has been employed to train an artificial neural network (ANN) using computational fluid dynamics (CFD) data to perform active flow control (AFC) around a 2-D circular cylinder. Flow control strategies are investigated at a diameter-based Reynolds number Re_D = 100 using advantage actor-critic (A2C) algorithm by means of two symmetric plasma actuators located on the surface of the cylinder near the separation point. The DRL agent interacts with the computational fluid dynamics (CFD) environment through manipulating the non-dimensional burst frequency (f+) of the two plasma actuators, and the time-averaged surface pressure is used as a feedback observation to the deep neural networks (DNNs). The results show that a regular actuation using a constant non-dimensional burst frequency gives a maximum drag reduction of 21.8 %, while the DRL agent is able to learn a control strategy that achieves a drag reduction of 22.6%. By analyzing the flow-field, it is shown that the drag reduction is accompanied with a strong flow reattachment and a significant reduction in the mean velocity magnitude and velocity fluctuations at the wake region. These outcomes prove the great capabilities of the deep reinforcement learning (DRL) paradigm in performing active flow control (AFC), and pave the way toward developing robust flow control strategies for real-life applications.

Numerical Simulation of Propulsion System Integration for Very High Bypass Ratio Engines

2012 ◽  
Author(s):  
Thierry Sibilli ◽  
Mark Savill ◽  
Vishal Sethi ◽  
David MacManus ◽  
Andrew M. Rolt
Keyword(s):  
System Integration ◽  
New Technologies ◽  
Engine Performance ◽  
Aircraft Design ◽  
Aircraft Engine ◽  
Fuel Burn ◽  
Active Core ◽  
Core Concepts ◽  
Work Programme ◽  
Bypass Ratio

Due to a trend towards Ultra High Bypass Ratio engines, confirmed in projects like NEWAC (New Aero Engine Core Concepts, an European Sixth Frame Work Programme) the corresponding engine/airframe interference is becoming a key aspect in aircraft design. Therefore detailed aerodynamic investigations are required to evaluate the real benefits of these new technologies. The work presented in this paper is to perform these investigations for two typical twin-engine/low-wing transports, using Computational Fluid Dynamics, in order to create a useful integration module for the in-house aircraft/engine performance software TERA2020 (Techno-economic Environmental and Risk Assessment for 2020). The paper presents results for two NEWAC engines: Intercooled Core Long Range (IC L/R) and the Active Core Short Range (AC S/R). The main results show that the engine horizontal positioning can influence mission fuel burn by up to 6.4% for AC S/R and 3.7% for IC L/R respectively.

scholarly journals Optimality considerations for propulsive fuselage power savings

2020 ◽  
pp. 095441002091631 ◽  
Author(s):  
Arne Seitz ◽  
Anaïs Luisa Habermann ◽  
Martijn van Sluis
Keyword(s):  
Boundary Layer ◽  
Power Saving ◽  
Aircraft Design ◽  
The European Union ◽  
Power Train ◽  
Analytical Formulation ◽  
Evaluation Approach ◽  
Fuel Burn ◽  
Aircraft Fuel ◽  
Range Equation

The paper discusses optimality constellations for the design of boundary layer ingesting propulsive fuselage concept aircraft under special consideration of different fuselage fan power train options. Therefore, a rigorous methodical approach for the evaluation of the power saving potentials of propulsive fuselage concept aircraft configurations is provided. Analytical formulation for the power-saving coefficient metric is introduced, and, the classic Breguet–Coffin range equation is extended for the analytical assessment of boundary layer ingesting aircraft fuel burn. The analytical formulation is applied to the identification of optimum propulsive fuselage concept power savings together with computational fluid dynamics numerical results of refined and optimised 2D aero-shapings of the bare propulsive fuselage concept configuration, i.e. fuselage body including the aft–fuselage boundary layer ingesting propulsive device, obtained during the European Union-funded DisPURSAL and CENTRELINE projects. A common heuristic for the boundary layer ingesting efficiency factor is derived from the best aero-shaping cases of both projects. Based thereon, propulsive fuselage concept aircraft design optimality is parametrically analysed against variations in fuselage fan power train efficiency, systems weight impact and fuselage-to-overall aircraft drag ratio in cruise. Optimum power split ratios between the fuselage fan and the underwing main fans are identified. The paper introduces and discusses all assumptions necessary in order to apply the presented evaluation approach. This includes an in-depth explanation of the adopted system efficiency definitions and drag/thrust bookkeeping standards.

Operations and aircraft design towards greener civil aviation using air-to-air refuelling

2006 ◽  
Vol 110 (1113) ◽  
pp. 705-721 ◽  
Author(s):  
R. K. Nangia
Keyword(s):  
Long Range ◽  
Design Space ◽  
Formation Flying ◽  
Aircraft Design ◽  
Civil Aviation ◽  
Environmental Aspects ◽  
Supersonic Transport ◽  
Fuel Savings ◽  
Fuel Burn ◽  
The Impact

Summary As civil aviation expands, environmental aspects and fuel savings are becoming increasingly important. Amongst technologies proposed for more efficient flight, air-to-air refuelling (AAR), ‘hopping’ and flying in close formation (drag reduction), all have significant possibilities. It will be interesting to know also how these technologies may co-exist e.g. AAR and formation flying. In military use, AAR is virtually indispensable. Its benefits are real and largely proven in hostile and demanding scenarios. We present a case for applying AAR in a civil context to show that substantial reductions in fuel burn for long-range missions are achievable. Overall savings, including the fuel used during the tanker missions, would be of the order of 30-40% fuel and 35-40% financial. These are very significant in terms of the impact on aviation’s contribution to reducing atmospheric pollution. AAR allows smaller, efficient (greener) aircraft optimised for about 3,000nm range to fulfil long-range route requirements. This implies greater usage of smaller airports, relieving congestion and ATC demands on Hub airports. Problems due to shed vortices and wakes at airports are reduced. Smaller engines will be needed. Integrated (accepted) AAR could lead to further benefits. Aircraft could take-off ‘light’, with minimum fuel and reserves and a planned AAR a few minutes into the flight. The ‘light’ aircraft would not require over-rating of the engines during take-off and would therefore be less noisy during take-off and climb-out, permitting more acceptable night operations. The availability of civil AAR will enable opportunities for hitherto borderline technologies to be utilised in future aircraft. Laminar flow will provide fuel savings and increased efficiency in its own right but could be significantly enhanced within a civil AAR environment. Similarly, supersonic transport may become an acceptable economic option. AAR affords the possibility of a complete widening of the design space and this should appeal to the imagination of current and future designers.

scholarly journals Influence of Novel Airframe Technologies on the Feasibility of Fully-Electric Regional Aviation

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 163
Author(s):  
Stanislav Karpuk ◽  
Ali Elham
Keyword(s):  
Energy Density ◽  
Active Flow Control ◽  
Aircraft Design ◽  
Operating Costs ◽  
Mission Analysis ◽  
Novel Technologies ◽  
Electric Aircraft ◽  
And Performance ◽  
Battery Energy ◽  
Active Flow

The feasibility of regional electric aviation to reduce environmental impact highly depends on technological advancements of energy storage techniques, available battery energy density, and high-power electric motor technologies. However, novel airframe technologies also strongly affect the feasibility of a regional electric aircraft. In this paper, the influence of novel technologies on the feasibility of regional electric aviation was investigated. Three game-changing technologies were applied to a novel all-electric regional aircraft: active flow control, active load alleviation, and novel materials and structure concepts. Initial conceptual design and mission analysis of the aircraft was performed using the aircraft design framework SUAVE, and the sensitivity of the most important technologies on the aircraft characteristics and performance were studied. Obtained results were compared against a reference ATR-72 aircraft. Results showed that an all-electric aircraft with airframe technologies might be designed with the maximum take-off weight increase of 50% starting from the battery pack energy density of 700 Wh/kg. The overall emission level of an all-electric aircraft with novel technologies is reduced by 81% compared to the ATR-72. On the other hand, novel technologies do not contribute to the reduction in Direct Operating Costs (DOC) starting from 700 Wh/kg if compared to an all-electric aircraft without technologies. An increase in DOC ranges from 43% to 30% depending on the battery energy density which creates a significant market obstacle for such type of airplanes. In addition, the aircraft shows high levels of energy consumption which concerns its energy efficiency. Finally, the sensitivity of DOC to novel technologies and sensitivities of aircraft characteristics to each technology were assessed.

Computational analysis of the aerodynamic performance of a jet-flap airfoil in transonic flow

2012 ◽  
Vol 226 (6) ◽  
pp. 664-678 ◽  
Author(s):  
V Mantič-Lugo ◽  
G Doulgeris ◽  
A Gohardani ◽  
R Singh
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Angle Of Attack ◽  
Aircraft Design ◽  
Civil Aviation ◽  
Commercial Aircraft ◽  
Angle Variation ◽  
Distributed Propulsion ◽  
Lift And Drag ◽  
Active Flow

The needed shift in next generation aircraft design is expected to bring novel concepts for civil aviation as the jet-flap wing. The aircraft efficiency improvements with the jet-flap wing directs its use for future aircraft designs reinforced by the tendency for more synergistic systems as active flow control, boundary layer ingestion and distributed propulsion, making the jet-flap wing a very suitable option for the latter concept. The analysis carried out in this paper is aimed at the application of the jet-flap wing concept for manoeuvrability and cruise efficiency improvement of an airliner. A 2D computational model of a jet-flapped transonic airfoil is developed in order to assess the jet-flap wing technology for a commercial aircraft at cruise conditions. This paper provides an insight into the parameters that affect the performance of a jet-flap under various flight conditions. To do this, a general parametrical analysis is performed, studying numerically the influences of main flow parameters like Mach number, Reynolds number, angle of attack, jet deflection angle and jet thickness. Changes in pressure distribution and flow circulation around the airfoil yield strong modifications in lift and drag due to jet angle variation. Improvements are encountered in the performance of an airfoil with a jet-flap system compared with a standard airfoil with no jet. Enhancements in lift and reduction in drag, as well as an increase of the lift-to-drag ratio is possible with a proper combination of the jet deflection and the angle of attack of the airfoil. In summary, this paper shows the conditions under which the benefits of the jet-flapped wing, for lift enhancement and manoeuvrability as an active flow control are promising.

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