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Hypersonic Flow Simulation Towards Space Propulsion Geometries

Universidade Da Beira Interior-Odelma Teixeira, Jose Pascoa
  • Technical Paper
  • 2019-01-1873
To be published on 2019-09-16 by SAE International in United States
This work aims to expand the applicability of an open-source numerical tool to solve hypersonic gas dynamic flows for space propulsion geometries. This is done by validating the code using two well-known hypersonic test cases, the double cone and the hollow cylinder flare, used by the NATO Research and Technology Organization for the validation of hypersonic flight for laminar viscous-inviscid interactions (D. Knight, "RTO WG 10 - Test cases for CFD validation of hypersonic flight," in 40th AIAA Aerospace Sciences Meeting & Exhibit, 2002). The Computational Fluid Dynamic (CFD) simulation is conducted using the two-temperature solver hy2Foam that is capable to study external aerodynamics in re-entry flows. In the present work the assessment of hy2Foam to solve hypersonic complex flow features with strong interactions including non-equilibrium effects was demonstrated. Freestream conditions with stagnation enthalpy of 5.44 MJ/kg and Mach number of 12.2, for the double cone case, and stagnation enthalpy of 5.07 MJ/kg and Mach number of 11.3 for the hollow cylinder case were considered. Comparison with newer existing numerical data and experimental data from…
 

Numerical Analysis of a Cycloidal Rotor Under Diverse Operating Conditions and Altitudes

Universidade Da Beira Interior-Mehdi Habibnia Rami, Jose Pascoa
  • Technical Paper
  • 2019-01-1872
To be published on 2019-09-16 by SAE International in United States
The current paper deals with the numerical study of the downwash flowfield characteristics in a cycloidal rotor. In an aircraft equipped with this kind of thruster, the downwash flow plays significant role in different flight modes. The interaction of this downwash jet with ground in effective height levels is studied using CFD simulations. Several operating conditions like pitching oscillation angles, rotation speeds and height levels are all considered in this work. The results declare that close-ground operating states augments the efficiency of cyclorotor. The vertical and horizontal forces of a single blade is also analyzed in a complete cycloid in different operating conditions. A lead and lag in maximum and minimum extremes of force curves of a single blade cycloid is obtained while being subjected to different functional conditions. These results strongly assure that an active control of both pitching oscillation and rotation speed is essential in operating at the optimum desired state.
 

Numerical investigation of Electrostatic Spray Painting Transfer Processes for vehicle Coating

Universidade Da Beira Interior-Mohammad Reza Pendar, Jose Pascoa
  • Technical Paper
  • 2019-01-1856
To be published on 2019-09-16 by SAE International in United States
In this study we examined numerically the electrostatic spray transfer processes in the rotary bell spray applicator, which is this case implemented in a full 3D representation. The algorithm implemented and developed for this simulation includes airflow, spray dynamics, tracking of paint droplets and an electrostatic modularized solver to present atomization and in-flight spray phenomena for the spray forming procedure. The algorithm is implemented using the OpenFOAM package. The shaping airflow is simulated via an unsteady 3D compressible Navier-Stokes method. Solver for particle trajectory was developed to illustrate the process of spray transport and also the interaction of airflow and particle that is solved by momentum coupling. As the numerical results in this paper indicates dominant operating parameter voltage setting, further the charge to mass ratio and air-paint flow rate deeply effect the spray shape and the transfer efficiency (TE). The spin of the bell forced the paint to fall off from the bell edge into the high-velocity airflow. By increasing the shaping airflow more uniform distribution of mass of paint is produced but the…
 

Safety Analysis of an Airship Which Loses Lifting Gas from the Hull

Sheffield Hallam University-Michele Trancossi
Universidade Da Beira Interior-Jose Pascoa
Published 2018-10-30 by SAE International in United States
This study investigates the physical phenomena that affect a high-altitude airship in the presence of lifting gas losses from the hull. General atmospheric thermodynamics and basic physical principles are adopted to describe the behavior of an airship with envelope failures that generate buoyant gas dispersion or depressurisation phenomena. Overpressure that could grant to maintain some controllability during a large part of the descent is assessed by mean of the thermodynamic model of the envelope in the presence of gas losses. Optimisation of the inflation parameters is provided and the conditions for avoiding dangerous crashes on the ground and the potential recovery of a damaged vehicle, people and its payload. In particular, the requirements for a slow depressurisation is computed by the equilibrium with the atmosphere and then how can it be possible to sustain controlled navigation are determined. A key factor for security relates directly to the capability of preserving some airship balloon overpressure for the longest time possible. This condition can extend much the range of control. Complete forfeit conditions will be determined to…
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Energetic, Environmental and Range Estimation of Hybrid and All-Electric Transformation of an Existing Light Utility Commuter Aircraft

Sheffield Hallam University-Michele Trancossi
Universidade Da Beira Interior-Jose Pascoa
Published 2018-10-30 by SAE International in United States
Today it is necessary to face the energetic, environmental, and safety-related issues of a significant industrial sector such as aeronautic one. It is a marginal contributor to today global GHG emissions (less than 3%), In any case, the associated impacts grows with the increase of air traffic with annual rate 5%. Consequently, aviation will need to face four fundamental problems for the future:1the overall impact of aviation is expected to grow up to 10÷15% of global GHG emissions by 2050;2the emissions of pollutants by commercial aviation affects the fragile atmospheric layers in the low stratosphere;3the increasing age of the flying fleet deals with increasing maintenance and safety issues;4the dependence on fossil fuels relates to problems of geopolitical instability and consequence volatility of prices.Substantial innovations are expected for both reducing energy consumption and environmental impacts of aviation and reducing the age of the fleets. They mostly relate to the decrease of weights and the introduction of environmental friendly propulsion systems, such as hybrid and all-electric propulsion.This paper will produce an assessment of different propulsive systems according…
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Control, Propulsion and Energy Assessment of a Spherical UAS for Low Speed Operations

Independent researcher-Sebastian Bandycki
Sheffield Hallam Univ.-Michele Trancossi
Published 2017-09-19 by SAE International in United States
This paper presents a comparison between different hypotheses of propulsion of a spherical UAS. Different architectures have been analyzed assessing their specific aerodynamic, energetic, and flight mechanics features. The comparison has been performed assuming the robustness of flight control in different wind conditions, defining for each the specific operative ranges, mission profiles, and energy assessment. An effective energy assessment and comparison against a commercial UAS has been produced. Even if the paper considers a preliminary simplified configuration, it demonstrates clearly to be competitive against traditional quadcopters in a predefined reference mission.
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A New VTOL Propelled Wing for Flying Cars: Critical Bibliographic Analysis

Sheffield Hallam Univ.-Michele Trancossi, Mohammad Hussain, Sharma Shivesh
Universidade Da Beira Interior-Jose Pascoa
Published 2017-09-19 by SAE International in United States
This paper is a preliminary step in the direction of the definition of a radically new wing concept that has been conceived to maximize the lift even at low speeds. It is expected to equip new aerial vehicle concepts that aim to compete against helicopters and tilt rotors. They aim achieving very good performance at very low speed (5 to 30 m/s) by mean of an innovative concept of morphing ducted-fan propelled wing that has been designed to maximize the lift force. This paper presents an effective bibliographic analysis of the problem that is a preliminary necessary step in the direction of the preliminary design of the wing. A preliminary CFD evaluation allows demonstrating that the claimed results are in line with the initial expectations. According to the CFD, results it has been produced a preliminary energetic evaluation of the vehicle in a flying car configuration by EMIPS method. Even if the results are still preliminary, they allow evidencing a good energy efficiency of the vehicle against helicopters.
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Temperature Oscillations in the Wall of a Cooled Multi Pulsejet Propeller for Aeronautic Propulsion

Chalmers University of Technology-Carlos Xisto
Sheffield Hallam University-Michele Trancossi
Published 2016-09-20 by SAE International in United States
Environmental and economic issues related to the aeronautic transport, with particular reference to the high-speed one are opening new perspectives to pulsejets and derived pulse detonation engines. Their importance relates to high thrust to weight ratio and low cost of manufacturing with very low energy efficiency. This papers presents a preliminary evaluation in the direction of a new family of pulsejets which can be coupled with both an air compression system which is currently in pre-patenting study and a more efficient and enduring valve systems with respect to today ones. This new pulsejet has bee specifically studied to reach three objectives: a better thermodynamic efficiency, a substantial reduction of vibrations by a multi-chamber cooled architecture, a much longer operative life by more affordable valves. Another objective of this research connects directly to the possibility of feeding the pulsejet with hydrogen. This paper after a preliminary analysis of the pulsejet takes into account two necessary stages of this activity with the initial definition of the starting point of this activity, which aim to define an initial…
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Preliminary Implementation Study of ACHEON Thrust and Vector Electrical Propulsion on a STOL Light Utility Aircraft

Nimbus SRL-Francesco Grimaccia
Universidade Da Beira Interior-Jose Pascoa, Shyam Das
Published 2015-09-15 by SAE International in United States
One of the best airplanes ever realized by the European Aircraft industry was the Dornier Do 28D Skyservant, an extraordinary STOL light utility aircraft with the capability to carry up to 13 passengers. It has been a simple and rugged aircraft capable also of operating under arduous conditions and very easy and simple maintenance.The architecture of this airplane, which has operated actively for more than 20 years, is very interesting analyzing the implementation of a new propulsion system because of the unusual incorporation of two engines, as well as the two main landing gear shock struts of the faired main landing gear attached to short pylons on either side of the forward fuselage. This unconventional design allows an easy implementation of different propulsion units, such as the history of different experimental versions allowed.This paper presents the preliminary definition of an increased performance cogeneration system for optimizing the energy efficiency and maximizing the thrust of ducted fan propeller. It then produces an effective design of the ACHEON nozzle for such an aircraft, the definition of the…
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Multifunctional Unmanned Reconnaissance Aircraft for Low-Speed and STOL Operations

Nimbus SRL-Alfredo Capuani, Francesco Grimaccia
Universidade Da Beira Interior-Shyam Das, Jose Pascoa
Published 2015-09-15 by SAE International in United States
This paper presents a novel UAS (Unmanned Aerial System) designed for excellent low speed operations and VTOL performance. This aerial vehicle concept has been designed for maximizing the advantages by of the ACHEON (Aerial Coanda High Efficiency Orienting-jet Nozzle) propulsion system, which has been studied in a European commission under 7th framework programme.This UAS concept has been named MURALS (acronym of Multifunctional Unmanned Reconnaissance Aircraft for Low-speed and STOL operation). It has been studied as a joint activity of the members of the project as an evolution of a former concept, which has been developed during 80s and 90s by Aeritalia and Capuani. It has been adapted to host an ACHEON based propulsion system. In a first embodiment, the aircraft according to the invention has a not conventional shape with a single fuselage and its primary objective is to minimize the variation of the pitching moment allowing low speed operations. The shape with convex wings has been specifically defined to allow a future possibility of enabling stealth operations.Main objective of the design activity has been…
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