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EFTV-G V47 internal subsystems 

EFTV-G V47 internal subsystems 

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Conference Paper
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This paper deals with the design trade-off activities undertaken to provide a trim-able, a statically and dynamically stable vehicle configuration able to perform a nominal experimental scramjet-propelled flight. The flight control activities and their impacts on vehicle layout and global aerodynamic performance are also addressed. In particular, d...

Citations

... Di Giorgio et al. [8] developed in-house code, with open-source software and research codes, which include modules for geometrical parametrization, automated data transfer between tools, automated execution of computational analysis codes, and design optimization methods, to provide an integrated optimization loop for shape design of an un-manned cruiser flying at hypersonic speed, corresponding to flight Mach number 8, at 30 km altitude (Earth's dense atmosphere), which this flight condition is similar to the Hypersonic Speed Civilian Transportation, under development by the European Space Agency within the Seventh Framework Program [9][10][11]. ...
Article
A two-dimensional mixed compression scramjet inlet design is presented in this work. The design is based on the static temperature and Mach number at the combustion chamber inlet according to the conditions required to burn hydrogen spontaneously at supersonic speed. This method considers air as a calorically perfect gas, with no viscous effects, and shock on-lip and shock on-corner. To burn hydrogen spontaneously at supersonic speed the mixture temperature of the income airflow and hydrogen is obtained considering the zeroth and first Laws of Thermodynamics. The criterion of equal shock strength, based on the normal component of the airflow velocity approaching the incident oblique shock waves, is applied to obtain the compression ramps angles and the airflow corresponding thermodynamic properties. Therefore, the total pressure ratio across all incident oblique shock waves and total temperature at the compression section are constants. Although the present method can be applied to any scramjet with a mixed compression system for any number of ramps, cases with up to 5 ramps, flying at a hypersonic speed corresponding to Mach number 7 through the Earth's atmosphere at 30 km of geometric altitude are considered. Finally, the same optimization criteria are extended to analyze the inlet of a scramjet vehicle with 5 compression ramps, flying at speeds from Mach numbers 5 to 10, at an altitude of 30 km.
... Furthermore, a creative example is to remodel the design principle of characteristic profile curves to construct an airframe/inlet integrated waverider [26]. As the waverider has been extensively researched to this date, it is chosen for several practical hypersonic flight projects [27][28][29]. Nevertheless, some of the practical considerations proposed in Ref. [30] still needs close attention to further the application of the waverider in practice. ...
Article
Full-text available
An ideal waverider has an infinite sharp leading edge, which causes difficulty for manufacture and aerothermal protection. Therefore, the leading edge of the waverider must be blunted. For this purpose, a parametric method for blunting the leading edge of the waverider is proposed here, which can fulfill the goals of setting a leading-edge blunt radius, achieving geometric continuity, and realizing the parametric design. First is the blunting procedure of the proposed method incorporating the construction of two-dimensional blunt curves and the integration of these curves on a three-dimensional waverider configuration. Second, waveriders blunted with different geometric continuities are built with corresponding computing grids generated. Numerical methods are then introduced and validated by the benchmark cases. Finally, results from these blunted configurations are presented and compared in terms of their geometric and flow characteristics. It shows that the proposed method has a better performance in the head region of the waverider and is thereby more suitable for the practical design.
... Recently, radically new hypersonic waverider concepts integrating highly efficient air breathing engines are challenging the need for ultra long-haul flights [5][6][7]. Advances in propulsion technology and waverider design methodologies creating high lift-to-drag ratios are showing potential to solve the problems which have previously hampered progress. To combat sonic boom issues, routes such as Brussels to Sydney would fly over the north pole and the pacific ocean to maximise high speed cruise. ...
... Similarly, yaw oscillations contain both sideslip and yaw motions. A summary of combined derivatives is given in Equations (1) to Equation (6). ...
Article
Hypersonic waveriders have the potential to significantly reduce travel times on long haul civilian transport routes. The design of hypersonic aircraft is heavily influenced by the aerodynamic efficiency at the cruise Mach number, resulting in less than ideal geometries for subsonic flight. Waverider aerodynamics and stability in the low speed regime is rarely investigated and not well understood, but is crucial for horizontal take-offs and landings. To date, low speed analyses of waverider shapes have been confined to static investigations, with limited work on longitudinal dynamics. No studies outlining the lateral-directional dynamic stability and aerodynamic derivatives has ever been published. This paper presents results for the low speed propelled variant of the Mach 8 HEXAFLY-INT waverider, which was subjected to forced oscillations in roll, yaw and side-to-side translations. This was achieved using unsteady Reynolds Averaged Navier Stokes simulations. Tests were conducted at a speed of 20 m/s, which correlates to a Reynolds number of approximately . The dynamic motion was at forced frequency of 1 Hz with angle amplitudes of 1 degree. The vehicle was analysed through an angle of attack range from -5 to 15 degrees in 5 degree increments. Results for the nominal centre of gravity location at 44.4% of the vehicle length show values for the dynamic derivatives within expected ranges, apart from the rolling moment due to yaw rate below approximately 2 degrees angle of attack. A similar finding for the dihedral derivative in static tests concluded that the low mounted wing with anhedral results in instabilities at low angles of attack. Investigations conducted at a centre of gravity location of 53.1% of the vehicle length, the aft static stability limit, also showed data within normal ranges. For these cases, the derivative magnitudes were lower, which indicates decreased damping compared to the nominal centre of gravity location. Some significant impact was seen on the roll damping derivative due to lowering the centre of gravity. This is from a combination of non-linear wing side force variance with angle of attack and the reduction of the moment arm, which resulted in less damping. The derivatives generally showed little sensitivity to changes in the oscillation frequency, with frequency rates ranging from 0.5 to 2 Hz tested. Overall, the results from this study highlighted the complex combinations of rate induced forces which contribute to the dynamic behaviour of the aircraft.
... Result comparisons carried out within the High-Speed Experimental Fly Vehicles-INTernational (HEXAFLY-INT) represent a further excellent evidence of CFD capabilities in supporting HSA design [49]. HEXAFLY-INT is an international project based on knowledge acquired from the previous European HSA projects, namely ATLLAS I and II [50,51] LAPCAT I and II [52,53], and HEXAFLY [54,55]. Fig. 13 shows the high-speed glider, namely Experimental Flight Test Vehicle (EFTV), with and without the Experimental Support Module (ESM), designed in the research programme [49]. ...
Article
Current design requirements are shaping advanced and efficient supersonic or hypersonic aircraft concepts, capable of flying between distant parts of the globe within hours, and making affordable and safe access-to-space transportation. To achieve this challenge, reliable design tools, like Computational Fluid Dynamics, are strongly integrated in multidisciplinary design procedures. In this framework, the present paper deals with the importance and capabilities of Computational Fluid Dynamics investigations, especially those involved in vehicle aerodynamic and aerothermodynamic appraisal, to support and feed the design of high-speed aircraft. At first the Computational Fluid Dynamics support in various phases of design is addressed. Furthermore, an overall vision on methodologies used in a high speed flow computation is also given, addressing advantages and drawbacks of classical methodologies versus modern hybrid RANS methods ones. Then, a brief overview on either numerical schemes and tools, routinely adopted in an hypersonic simulation, is presented with reference to the multi-scale accuracy required by high supersonic/hypersonic flow regime. Finally, to provide a complete template for future numerical experiments, several Computational Fluid Dynamics activities, performed for a number of high-speed aircraft in different flow regimes, ranging from subsonic up to hypersonic speed, are reported and discussed. Computational methodology, domain discretization, and the support to design activity are provided for the CIRA USV1 and USV3, ESA-IXV, HEXAFLY-INT, a space launcher, and a Mars entry capsule. These examples show that Computational Fluid Dynamics can no longer be considered only an analysis tool, but it allows great advantages in all design stages, from conceptual up to detailed design level.
... This dihedral shape improves rolling stability as well as lateral/directional stability. The dihedral effect (Etkin and Reid, 1996) stability condition (C lβ <0) is put forward to prescribe a limit on the relationship between the dihedral angle and the lateral stability, so that as a consequence of disturbance of the angle of sideslip the airplane will roll away from the disturbance and sideslip will decrease (Pezzella et al., 2014). Computational fluid dynamics (CFD) aerodynamic data show that the dihedral stability of HIFiRE 6 changes with Mach number (Adamczak and Bolender, 2015;Favaloro et al., 2015). ...
Article
Full-text available
When considering the practical engineering application of a waverider, the on-design and off-design aerodynamic characteristics of the design conditions, especially the lift-to-drag ratio and the stability, deserve attention. According to recently studies, the planform and rear sight shape of a waverider are closely related to the above aerodynamic performance. Thus, the planform leading-edge profile curve used to design the planform shape of a vehicle is applied to designing an osculating cone waverider. Two key parameters concerned in planform and rear sight shape, namely the plan view sweep angle of the leading edge and the dihedral angle of the underside are introduced to the waverider design process. Each parameter is inserted in the control curve equation. Especially, a parameterization scheme is put forward for the free adjustment of the sweep angle along the leading edge. Finally, three examples are generated for verification and investigation. After the verification process based on the inviscid flow field of one case, the influences of the sweep and dihedral angles on the lift-to-drag ratio and the lateral static stability are evaluated, and meaningful results are obtained. Based on these results, we can conclude that, considering the maximum lift-to-drag ratio, the sweep angle plays a role on the lift-to-drag ratio only at subsonic and trans/supersonic speed as a negligible effect is observed at hypersonic speeds, whereas the dihedral angle is seem to produce a relevant difference at hypersonic speeds. Considering the lateral static stability, the dihedral angles have more influence on the waverider than the sweep angles.
... Recently, radically new hypersonic waverider concepts integrating highly efficient air breathing engines are challenging the need for ultra long-haul flights [5][6][7]. Advances in propulsion technology and waverider design methodologies creating high lift-to-drag ratios are showing potential to solve the problems which have previously hampered progress. To combat sonic boom issues, routes such as Brussels to Sydney would fly over the north pole and the pacific ocean to maximise high speed cruise. ...
Article
Hypersonic waveriders have the potential to significantly reduce travel times on long haul civilian transport routes. The design of hypersonic aircraft is heavily influenced by the aerodynamic efficiency at the cruise Mach number, resulting in less than ideal geometries for subsonic flight. Waverider aerodynamics and stability in the low speed regime is rarely investigated and not well understood, but is crucial for horizontal take-offs and landings. To date, low speed analyses of waverider shapes is confined to static investigations, with no studies on the dynamic behaviour ever completed. This paper presents results from unsteady Reynolds Averaged Navier Stokes simulations modelling pitching and plunging forced oscillations of the low speed propelled variant of the Mach 8 HEXAFLY-INT waverider. Tests were conducted at a speed of 20 m/s, which correlates to a Reynolds number of approximately 1.5×106. Pitching and plunging oscillations were at 1 Hz with an angle of attack amplitude of 1 degree. The vehicle was analysed through an angle of attack range from -5 to 15 degrees in 5 degree increments. Results for the HEXAFLY-INT aircraft at the nominal centre of gravity location, 44.4% of the vehicle length, show that the vehicle is positively damped for all cases tested. Static derivative predictions extracted from the dynamic data showed strong agreement with existing static CFD and wind tunnel results. Further dynamic investigations conducted at a centre of gravity location of 53.1% of the vehicle length, the aft static stability limit, also showed positive damping. For these cases, the derivative magnitudes were lower, which indicates decreased damping compared to the nominal centre of gravity location. The vehicle was generally not sensitive to changes in driving frequency, with oscillation rates ranging from 0.5 to 2 Hz tested. However, during plunging tests, the pitching moment derivative was seen to change by as much as 22%. This is attributed to changes in the leading edge vortices with AoA rate. The results from this study, along with previous work looking at the static aerodynamics, stability and control authority, show the feasibility of moving to the flight test phase, but the aircraft dynamic stability in the lateral-directional planes must first be investigated.
... Recently, radically new hypersonic waverider concepts integrating highly efficient air breathing engines are challenging the need for ultra long-haul flights [5][6][7]. Advances in propulsion technology and waverider design methodologies creating high lift-to-drag ratios are showing potential to solve the problems which have previously hampered progress. To combat sonic boom issues, routes such as Brussels to Sydney would fly over the north pole and the pacific ocean to maximise high speed cruise. ...
... m from the origin as shown in Fig. 4. This is approximately 44.4% of the vehicle length, which is further upstream than the hypersonic glider configuration of 55% [6]. ...
... Recently, radically new hypersonic waverider concepts integrating highly efficient air breathing engines are challenging the need for ultra long-haul flights [5][6][7]. Advances in propulsion technology and waverider design methodologies creating high lift-to-drag ratios are showing potential to solve the problems which have previously hampered progress. To combat sonic boom issues, routes such as Brussels to Sydney would fly over the north pole and the pacific ocean to maximise high speed cruise. ...
... m from the origin as shown in Fig. 4. This is approximately 44.4% of the vehicle length, which is further upstream than the hypersonic glider configuration of 55% [6]. ...
Article
Hypersonic waveriders have the potential to significantly reduce travel times on long haul civilian transport routes. The design of hypersonic aircraft is heavily influenced by the aerodynamic efficiency at the cruise Mach number, resulting in less than ideal geometries for subsonic flight. Waverider aerodynamics and stability in the low speed regime is rarely investigated and not well understood, but is crucial for horizontal take-offs and landings. This paper presents a combination of numerical simulation results and experimental data for the low speed propelled variant of the Mach 8 HEXAFLY-INT waverider. Aerodynamic, control and stability testing for lateral-directional cases was conducted in the University of Sydney 4 foot by 3 foot low speed facility. Computational fluid dynamics simulations are compared with wind tunnel tests for angles of attack between -5 and 15 degrees and angles of sideslip between -8 and 8 degrees. Throughout these ranges, aileron and rudder deflections up to 10 degrees are investigated. Results show that the vehicle aerodynamics are dominated by asymmetric wing and fin vortices, resulting in non-linear aerodynamic forces. At a centre of gravity location of 44.4% of the vehicle length the aircraft is stable directionally, but has lateral instability at angles of attack below -2 degrees. This is attributed to the low mounted wings with anhedral. The instability is minor and is not expected to result in an uncontrollable condition. Lowering the centre of gravity by approximately 2 centimetres, or 17% of the local fuselage height, can correct the instability. Lateral-directional dynamic stability was predicted using static derivatives and was found to be stable through the entire AoA range tested, with no dependence on mass moments of inertia. Both aileron and rudder controls are found to provide sufficient control authority, but the aircraft may benefit from increased rudder size. The results from this study, along with previous work on longitudinal stability and performance show the feasibility of moving to the flight test program, but aircraft dynamic stability must first be investigated.
... History shows that commercial high speed vehicles are rarely taken past the concept phase, as they are limited by low cruise efficiency, high fuel consumption and reduced range [1]. Some for ultra long-haul flights [4][5][6]. Advances in propulsion technology and waverider design methodologies creating high lift-to-drag ratios are showing potential to solve the problems which have previously hampered progress. To combat sonic boom issues, routes such as Brussels to Sydney would fly over the North Pole and the Pacific Ocean to maximise high speed cruise. ...
Article
Hypersonic waveriders have the potential to significantly reduce travel times on long haul civilian transport routes. The design of hypersonic aircraft is heavily influenced by the aerodynamic efficiency at the cruise Mach number, resulting in less than ideal geometries for subsonic flight. Waverider aerodynamics and stability in the low speed regime is rarely investigated and not well understood, but is crucial for horizontal take-offs and landings. This paper presents a combination of numerical simulation results and experimental data for the low speed variant of the Mach 8 HEXAFLY-INT waverider. Aerodynamic, control and stability testing was conducted in the University of Sydney 4 foot by 3 foot low speed facility, while propulsion testing of the vehicle-integrated electric ducted fan was completed in the 7 foot by 5 foot tunnel. Motor thrust settings were tested for 8 lithium polymer cells connected serially drawing between 5 and 25 amperes. Computational fluid dynamics simulations are compared with wind tunnel tests for angles of attack between −5 and 25 degrees and elevon deflections between −10 and 10 degrees. Results show the aerodynamics is dominated by leading edge flow separation and vortex lift. At a centre of gravity location of 44.4% of the vehicle length, stability is observed up to 22 degrees angle of attack. Past this point, instability occurs due to vortex breakdown. The centre of gravity aft stability limit was found at 53.1% of the vehicle length. Overall, good agreement is seen between simulation and tunnel data, validating the modelling methods used. The low speed demonstrator can achieve trimmed flight from 12 m/s, but is only speed stable above 19 m/s. A cruise speed of 19 m/s is selected and can be attained with approximately −9.2 degrees of elevon and 7.1 degrees AoA for a centre of gravity location of 44.4%. Shifting the centre of gravity aft can reduce the trim angle of attack to below 6 degrees with −4 degrees elevon deflection. Take-off and landing can be achieved at 15 m/s between 9.8 and 12 degrees angle of attack, depending on centre of gravity configuration. Amaximum climb rate of 2.1 m/s is predicted at 16.3 m/s based on the power settings tested. Overall, the results show the aircraft satisfies stability and performance requirements in the longitudinal axis.
... 1. High-Speed Vehicle Concepts to assess the overall vehicle performance in terms of cruiseefficiency, range potential, aero-propulsive balance, aero-thermal-structural integration, etc... [4] [5], and HEXAFLY [6] [7]. Under HEXAFLY-INT, both a glider and a hydrogen-propelled variant of the high-speed vehicle are being considered, the former being developed by EC partners with international partners, the latter being developed only by the Russian partners. ...
Conference Paper
Full-text available
Civil high-speed passenger transport only makes sense when deployed for long-haul intercontinental flights. Consequently, the related development and deployment of such a high-speed vehicle will most likely demand an international approach. The internationally funded HEXAFLY-INT project is a first step in the direction of civil high-speed transportation along with an international development where flighttesting is the focal point. The global aim is to flight test an experimental waverider-based vehicle concept above Mach 7 to verify its potential for a high cruise efficiency during a free-flight. In parallel, the concept will also be flight tested to prove the waverider concept is also able to take-off, to accelerate to subsonic speed and to land in an efficient and robust way. The feasibility for a 3m long vehicle was demonstrated during the European precursor project HEXAFLY. Its realization is now being enabled on an international scale preparing the grounds for global cooperation in case of a future deployment of a high-speed cruiser. These flight opportunities will increase drastically the Technology Readiness Level of developments realized in previous high-speed EC projects such as ATLLAS I & II and LAPCAT I & II. The present paper describes the various numerical and experimental investigations carried out so far by the different international partners.