Due to the growing demand for comfort, the noise generated by HVAC components should be considered by the designers. Flow induced noise is one of the major contributors to the noise in HVAC systems. By means of computational aero-acoustics(CAA), the mechanism of noise generationis able to be studiedin the design phase. This research has been conducted based on a simplified HVAC duct, aiming to validate a hybrid method in CAA. The hybrid method is an affordable and promising approach for industrial applications. CFD simulation, as the first step of the hybrid method, has been performed. Due to the deficiency of RANS and high computational cost of LES, hybrid RANS-LES approaches are employed to combine sufficient accuracy and reduced cost. Delayed Detached Eddy Simulation (DDES) and Scale Adaptive Simulation (SAS), as the representative hybrid RANS-LES approaches, are performed and compared. CFD results are shown in detail and compared with the experimental measurements available in the literature. The comparison shows a good agreement for the time averaged flow field and a fairly good agreement for uns teady flow phenomena. Discrepancies between numerical results and measurements can be observe dregarding mainly unsteady pressure fluctuations.The influence study of grid, discretization schemes, time step as well as other parametersis also conducted. The insights gained here can serve as a guideline for future complex applications.

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This paper presents a new revolutionary design in commercial aircraft: the conven-tional vertical and horizontal tails are not present as generally known, and their contri-bution to the manoeuvering of the aircraft, namely the presence of the rudder and theelevators, is achieved by locating them at the wingtips and in the canard, respectively.Substituting the horizontal tail with the canard, the possibility of dividing the fuel be-tween the wing (where it is located conventionally) and the canard allows the pilot tochange the center of gravity during the ight with more freedom, while the eect of theelevators continues present. Locating the vertical stabilizers at the wingtips combinesthe eect of the vertical stabilizer and the winglet all in one, with the corresponding lostof weight. In this sense, the aerodynamic, stability and aeroelastic characteristics of anaircraft such as the one described have been analyzed using dierent modules belongingto CEASIOM program, and the results are very encouraging, showing that it is reallyfeasible to change the current concept of the commercial aircraft without penalizing theperformance.

Denna rapport innehåller aerodynamiska beräkningar för en rysk månlandare vilken planeras premiärflyga 2018. Återinträde sker lyftkraftgenererat med flack återinträdesvinkel. Beräkningarna med Newtons modifierade impulsteori är genomförda på den främre delen, sfäriska kalotten med krökningsradie 5 m och diameter 4,4 m , av återinträdeskapseln.

Building planes is based on a lot of different manufacturing processes. New challenges and higher production rates lead to the necessity of optimizing those processes. This Master Thesis focuses on one of them: the plane transit process, when the plane moves from a building station to another. Today, this manufacturing step takes a lot of time and deteriorates the production rhythm. This gate has a direct impact on the provider and the receiver stations and it was essential to find a way of improving it. This document presents the A330 Final Assembly Line (FAL), the plane transit process, the Business Improvement Project (BIP) method at Airbus and explains the created solutions and the related results.

In this paper, an analysis in computational uid dynamics (CFD) is presented on a helicopter scale model with focus on the main-rotor blades.The helicopter model is encapsulated in a background region and the ow eld is solved using Star CCM+. A surface and volume mesh continuum was generated that contained approximately seven million polyhedral cells, where the Finite Volume Method (FVM) was chosen as a discretization technique. Each blade was assigned to an overset region making it possible to rotate and add a cyclic pitch motion. Boundary information was exchanged between the overset and background mesh using a weighted interpolation method between cells. An implicit unsteady ow solver, with an ideal gas and a SST (Mentar) K-Omega turbulence model were used. Hover and forward cases were examined. Forward ight cases were done by changing the rotor shaft angle of attacks and the collective pitch angle 0 at the helicopter freestream Mach number of M = 0:128, without the inclusion of a cyclic pitch motion. An additional ight case with cyclic pitch motion was examined at s = 0 and = 0. Each simulation took roughly 48 hours with a total of 96 parallel cores to compute. Experimental data were taken from an existing NASA report for comparison of the results. Hover ight coincided well with the wind tunnel data. The forward ight cases (with no cyclic motion) produced lift matching the experimental data, but had diculties in producing a forward thrust. Moments in roll and pitch started to emerge. By adding a cyclic pitch successfully removed the pitch and roll moments. In conclusion this shows that applying overset meshes as a way to analyze the main-rotor blades using CFD does work. Adding a cyclic pitch motion at 0 = 5 and s = 0 successfully removed the roll and pitching moment from the results.

The purpose of the investigation presented here is to study the degree of correlation between the density gradient in the near eld and the aeroacoustic sound generation in the far eld of a cold jet. The variations of the density gradient in the ow are visualized and  recorded by the Background Oriented Schlieren (BOS) technique. In this method high power LEDs are used as illumination source. Simultaneously the pressure uctuations in the acoustic far-eld are recorded by a set of microphones. Measurements on a round nozzle and a chevron nozzle are conducted and the obtained results are compared. Large structures emitting noise are localized, being in the case of the chevron nozzle further upstream due to the higher level of entrainment of the jet with the surrounded ambient uid. In addition, it is demonstrated that the noise produced by these structures is radiated mainly downstream, having the highest correlations with the pressure uctuations recorded with the microphone located at an angle Ø= 26X respect to the jet-axis.

This paper deals with the study of the robustness concerning the attitude control of the spacecraft TARANIS regarding disturbances on its sun acquisition sensors. Two kinds of disturbances have been studied: the masking of the sunlight by the dierent spacecraft devices as well as the sunlight reexion on their surface. This study has been performed by doing rst the sensor and observer modeling on a simulator specially designed for the study from the whole spacecraft simulator. Then the modeling of the disturbances has been achieved depending on the characteristics of the sources in terms of size, positioning, roughness and light reection. Finally a set of simulations of the acquisition and survival mode has been executed in order to evaluate the impact of the disturbances on its convergence time. The study shows that the algorithm designed to calculate the spacecraft attitude from the solar sensors data set is robust concerning these disturbances with the actual design of the satellite, but also shows limits concerning the size and positioning of its devices.

Despite the recent increase in the amount of smaller electric general aviation aircrafts, a fully electric airliner is not likely to fly in the near future. Partially inspired by the automotive industry’s success with the hybrid car, this thesis investigated the feasibility of an electric-hybrid propulsion system for an Airbus A340-600 on a long-haul flight and its effect on the aircraft’s performance. First, an analysis was done of the reference aircraft, A340-600, using conventional propulsion. Second, a 5700 nautical miles flight was modelled to determine performance data such as the power and thrust requirements during the different flight phases. Third, the flight phases where electric propulsion would be implemented were identified and an optimum ratio between conventional and electric propulsion was calculated. Finally, a detailed performance analysis of the new hybrid electric aircraft comparing it to a conventional aircraft was conducted. The maximum available conventional thrust was reduced to a certain percentage of the maximum thrust. Primarily conventional thrust is used, however when it is no longer sufficient, additional thrust is gained through electric propulsion. Conventional thrust ratio of 69.5%, 63.5% and 59.5% of total thrust was investigated yielding 8680 kg, 10500kg and 8585kg of payload decrease respectively. Net energy of 6.70MWh, 11.71MWh and 31.06MWh is required and the electric engines need to provide 21.3 MW, 25.5 MW and 28.3 MW of net power respectively. Partial electric propulsion will result in increased weight; however, it will also give room for further performance optimisation and technical innovations. On the one hand, the conventional engines will run at a constant speed throughout the flight allowing for better optimisation at a specific design point. On the other hand, electric engines are more reliable and require less maintenance than conventional engines. Furthermore, lower fuel consumption means less carbon-dioxide emissions. An exemption from CO2-taxes, similar to measures implemented for hybrid cars in certain countries, could financially justify use of the aircraft by airlines and compensate for the decrease in payload. Since a fully electric propelled airliner is not likely to fly for several decades, a hybrid-airliner would be a suitable alternative for the transition period from fossil fuels to electric energy.

This paper presents the work done at the High Pressure Compressor design division of Safran Snecma to simulate the flutter behaviour of a compressor blisk at reversed flow conditions. The report states the preliminary phase of modelling the reversed flow on an entire compressor with a stationary simulation and the single blade aeroelastic study results obtained. One can then get interpretations on the blow down aerodynamics that can affect the mechanical behaviour of the blade. Eight simulations of a single blade model have been done on two aeroelastic configurations, each one on a rotor from two different compressor designs. By investigating the airflow around the blade profiles, it becomes possible to get values on the aerodynamic damping on the blade. As presented below, even with strong surge stresses, the compressor stage will remain flutter-free.