This file was created by the Typo3 extension sevenpack version 0.7.16 --- Timezone: CEST Creation date: 2023-03-30 Creation time: 22-28-12 --- Number of references 26 article Gilotte2022 International Journal of Numerical Methods for Heat & Fluid Flow 2022 32 4 1222-1236 The purpose of this paper is to study pressure measurement correlations, as the location of the pressure sensors should enable to capture variation of the drag force depending on the yaw angle and some geometrical modifications. The present aerodynamical study, performed on a reduced scale mock-up representing a sport utility vehicle, involves both numerical and experimental investigations. Experiments performed in a wind tunnel facility deal with drag and pressure measurements related to the side wind variation. The pressure sensor locations are deduced from wall streamlines computed from large After validation of the drag coefficient (Cd) values computed with an aerodynamic balance, measurements should only imply pressure tap mounted on the vehicle to perform real driving emission (RDE) tests. Relation presented in this paper between pressure coefficients measured on a side sensor and the drag coefficient data must enable to better quantify the drag force contribution of a ground vehicle in RDE tests. https://www.emerald.com/insight/0961-5539.htm Keywords Cross-correlation, Drag reduction, Ground vehicle, Real driving emissions test,Wind tunnel measurements, Yaw angle variation https://doi.org/10.1108/HFF-08-2021-0522 0961-5539 10.1108/HFF-08-2021-0522 P.Gilotte I.Mortazavi A.Colon de Carvajal S.Edwige C. N.Nayeri article haghdoost2020dynamic Physical Review Fluids 2020 5 7 073401 The dynamic evolution of a highly underexpanded transient supersonic jet at the exit of a pulse detonation engine is investigated via high-resolution time-resolved schlieren and numerical simulations. Experimental evidence is provided for the presence of a second triple shock configuration along with a shocklet between the reflected shock and the slipstream, which has no analog in a steady-state underexpanded jet. A pseudo-steady model is developed, which allows for the determination of the postshock flow condition for a transient propagating oblique shock. This model is applied to the numerical simulations to reveal the mechanism leading to the formation of the second triple point. Accordingly, the formation of the triple point is initiated by the transient motion of the reflected shock, which is induced by the convection of the vortex ring. While the vortex ring embedded shock move essentially as a translating strong oblique shock, the reflected shock is rotating towards its steady-state position. This results in a pressure discontinuity that must be resolved by the formation of a shocklet. https://link.aps.org/doi/10.1103/PhysRevFluids.5.073401 American Physical Society 2469-990X 10.1103/PhysRevFluids.5.073401 M.Rezay Haghdoost D.Edgington-Mitchell M.Nadolski R.Klein K.Oberleithner article RezayHaghdoost2020a AIAA Journal 2020 58 8 3527--3543 https://arc.aiaa.org/doi/abs/10.2514/1.J058540 https://arc.aiaa.org/doi/10.2514/1.J058540 0001-1452 10.2514/1.J058540 M.Rezay Haghdoost D.Edgington-Mitchell C. O.Paschereit K.Oberleithner article paredes-cisneros_simulation_2020 Physica Medica 2020 70 109--117 https://linkinghub.elsevier.com/retrieve/pii/S1120179720300144 11201797 10.1016/j.ejmp.2020.01.012 I.Paredes-Cisneros C.Karger P.Caprile D.Nolte I.Espinoza A.Gago-Arias inbook Noack_102020 2020 145 77-90 The present study investigates the lift gains generated by the superpositionof a periodic actuation component onto a steady component on an airfoil with ahighly deflected Coanda flap. The presented results are drawn from two experimentsconduced in the water and in the wind tunnel. For the water tunnel experiment,periodic actuation is provided by two synchronized specially modified valves thatdeliver actuation frequency up to 30Hz. For the wind tunnel experiment, the unsteadyactuation is generated by 33 specially-designed individually-controlled lip segmentsthat deliver actuation frequencies up to 300 Hz. The results demonstrate the benefitsof superimposing a periodic component onto the steady actuation component fora separated or partially-attached flow, where a lift increase of up to ΔCl = 0.6 isachieved. Among spanwise-varied actuation, the traveling wave yield the highest liftgains with a relatively high wave frequency and long wavelength. https://link.springer.com/book/10.1007/978-3-030-52429-6 Radespiel, J. and Semaan, R. Fundamentals of high lift for future civil aircraft. Contributions to the final symposium of the collaborative research center 880 978-3-030-52429-6 R.Semaan Y.El-Sayed S.Loges B. R.Noack J.Radespiel conference Noack_2020 2020 1 6 active flow control, Coanda blowing, piezo actuator https://elib.dlr.de/127971/ AIAA Orlando, Fl. USA AIAA SciTech Forum 6-1-2020 Y.El-Sayed N.Gomes de Paula B.Genest R.Semaan J.Radespiel R.Petersen C.Behr P.Wierach B. R.Noack inproceedings rezay2020evaluation 2020 926 https://arc.aiaa.org/doi/10.2514/6.2020-0926 American Institute of Aeronautics and Astronautics

Reston, Virginia

AIAA Scitech 2020 Forum 978-1-62410-595-1 10.2514/6.2020-0926 M.Rezay Haghdoost B.Thethy M.Nadolski R.Klein D.Honnery D.Edgington-Mitchell B.Seo C. O.Paschereit K.Oberleithner inproceedings thethy2020redistribution 2020 925 https://arc.aiaa.org/doi/10.2514/6.2020-0925 American Institute of Aeronautics and Astronautics

Reston, Virginia

AIAA Scitech 2020 Forum 978-1-62410-595-1 10.2514/6.2020-0925 B.Thethy M.Rezay Haghdoost C. O.Paschereit D.Honnery D.Edgington-Mitchell KilianOberleithner article Eulalie2018 International Journal of Numerical Methods for Heat & Fluid Flow 2018 Purpose This research paper presents an experimental investigation of an active flow control solution mounted at rear of a Sport Utility vehicle (SUV) with the objective of drag reduction, thanks to a selection of flow control parameters leading to a pressure increase on the tailgate. Design/methodology/approach A flow control design of experiments was conducted with a pulsed jet system mounted on the top and sides of the rear window of the vehicle. The wall pressure, instantaneous velocity and drag were measured with this prototype in a wind tunnel. A Dynamic Modal Decomposition (DMD) analysis of the pressure enables to describe the pressure fluctuations. Fluid Dynamic Computations show relation between pressure and velocity fields. Findings Measurements with this prototype in the wind tunnel revealed small improvements in drag for the best flow control configurations. This small benefit is due to the core of the upper span wise vortex further away from the rear window than the lower span wise vortex. These small improvements in drag were confirmed with pressure measurements on the rear window and tailgate. The DMD analysis of the surface pressure showed a low frequency pendulum oscillation on the lower area of the tailgate, linked with low velocity frequencies in the shear layers near the tailgate. Originality/value Experimental and numerical results show interest to increase pressure at bottom of the rear end of this SUV prototype. The dynamic description of the wall pressure shows importance of flow control solutions reducing pressure fluctuations at low frequencies in the lower area of the tailgate. https://www.emeraldinsight.com/doi/abs/10.1108/HFF-06-2017-0230# 0961-5539 10.1108/hff-06-2017-0230 Y.Eulalie E.Fournier Ph.Gilotte D.Holst S.Johnson C. N.Nayeri Th.Schütz D.Wieser proceedings Edwige2018 ASME 2018 5th Joint US-European Fluids Engineering Division Summer Meeting 2018 2 Development and Applications in Computational Fluid Dynamics; Industrial and Environmental Applications of Fluid Mechanics; Fluid Measurement and Instrumentation The research on the external aerodynamics of ground vehicles can nowadays be related to sustainable development strategies, confirmed by the worldwide CO2 regulation target. Automotive manufacturers estimate that a drag reduction of 30% contributes to 10g/km of CO2 reduction. However, this drag reduction should be obtained without constraints on the design, the safety, comfort and habitability of the passengers. Thus, it is interesting to find flow control solutions, which will remove or remote recirculation zones due to separation edges with appropriate control techniques. In automotive sales, the SUV, 4x4 and compact cars represent a large part of the market share and the study of control approaches for this geometry is practically useful. In this work, appropriate control techniques are designed to decrease the drag forces around a reduced scale SUV car benchmark called POSUV. The control techniques are based on the DMD (Dynamic Mode Decomposition) algorithms generating an optimized drag reduction procedure. It involves independent transient inflow boundary conditions for flow control actuation in the vicinity of the separation zones and time resolved pressure sensor output signals on the rear end surface of the mockup. This study, that exploits dominant flow features behind the tailgate and the rear bumper, is performed using Large Eddy Simulations on a sufficient run time scale, in order to minimize a cost function dealing with the time and space average pressure coefficient. The resulting dynamic modal decomposition obtained by these LES simulations and by wind tunnel measurements has been compared for the reference case, in order to select the most appropriate run time scale. Analysis of the numerical results shows a significant pressure increase on the tailgate, for independent flow control frequencies. Similar decomposition performed in the wake with and without numerical flow control help understanding the flow modifications in the detachment zones. Montreal, Quebec, Canada, July 15–20, 2018 http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2710650 ASME Proceedings | 25th Symposium on Industrial and Environmental Applications of Fluid Mechanics ASME 978-0-7918-5156-2 10.1115/FEDSM2018-83444 S.Edwige Ph.Gilotte I.Mortazavi Y.Eulalie D.Holst C. N.Nayeri J.-L.Aider E.Varon article Fischer2015 DEWEK 2015 2015 The development of a medium scale research wind turbine is a part of the research project PAK 780 funded by the German Science Foundation (DFG). In this project six universities from all over Germany join forces and pursue fundamental research in the field of wind turbine aerodynamics, inflow turbulence as well as wake and flow control. The Modular Research Wind Turbine (MoReWiT) design and development is an integral part of this research program designed to assist the research tasks of all project partners. The PAK 780 project consists of HFI TU Berlin, RWTH Aachen, Univ. of Oldenburg, Univ. of Stuttgart and TU Darmstadt and it is one of the major DFG funded projects in wind energy. Book of abstracts 2015 http://15.dewek.de/fileadmin/downloads/Book_of_Abstracts_2015.pdf DEWI J.Fischer O.Eisele G.Pichlivanoglou S.Vey C. N.Nayeri C. O.Paschereit incollection Greenblatt2015 2015 127 71-86 Rudibert King Springer Notes on Numerical Fluid Mechanics and Multidisciplinary Design Active Flow and Combustion Control 2014 978-3-319-11966-3 10.1007/978-3-319-11967-0 D.Greenblatt H.Müller-Vahl R.Lautman A.Ben-Harav B.Eshel article Mitchell2014 Journal of Fluid Mechanics 2014 6 748 822--847 http://journals.cambridge.org/article_S0022112014001736 1469-7645 10.1017/jfm.2014.173 D.Edgington-Mitchell K.Oberleithner D. R.Honnery J.Soria inproceedings Eisele2011 2011 Conventional wind turbine rotor blades are exposed to unsteady aerodynamic loads caused by wind gusts. Typically, the wind gusts have a duration of 1s to 10min, whereby maximum wind gusts with speeds 1.7 times faster than the hourly mean wind speed can occur [1]. These dynamic loads lead to undesired responses of the blade flap and chord-wise oscillations. The lifetime of a blade is significantly reduced by fatigue due to this effect. Furthermore, the tower is adversely affected by the resulting rotor dynamics. A proper way to minimize unsteady aerodynamic loads on rotor blades is to apply active flow control elements. Such solutions however require appropriate sensors and control strategies in order to ensure a stable operation. Designing a conventional controller for active flow control elements on a real wind turbine blade requires a very large amount of physical insights. However, the aerodynamics and aeroelastic effects on wind turbine blades are not yet well understood. Because of this lack, a feasible way of designing a controller is to use the so-called black box method. Thereby the controller is designed by observing inputs and outputs without taking into account the dynamics in between. http://www.ewec2010proceedings.info/ewea2011/papers/170.pdf EWEA 2011 (European Wind Energy Association), Brussels, Belgium, 14-17 March O.Eisele G.Pechlivanoglou C. N.Nayeri C. O.Paschereit inproceedings Pfeifer2010 2010 36. Deutsche Jahrestagung für Akustik, Dresden, 15.03. - 18.03.2010 C.Pfeifer B.Pardowitz C. O.Paschereit L.Enghardt inproceedings Eisele2010 2010 http://smart-blade.com/fileadmin/downloads/abstract_plasma.pdf Proceedings of DEWEK 2010, 17-18 November 2010, Bremen, Germany O.Eisele G.Pechlivanoglou C. N.Nayeri C. O.Paschereit inproceedings Pfeifer2009 2009 XVIII 269-291 Schwarz, A. and Janicka, J. Springer-Verlag Berlin Combustion Noise 978-3-642-02037-7 C.Pfeifer C. O.Paschereit J. P.Moeck L.Enghardt inproceedings Emara2009 2009 Proc. 45th AIAA/ ASME/ SAE/ ASEE Joint Propulsion Conference, Denver, USA 1-56347-976-1 (DVD) A.Emara A.Lacarelle C. O.Paschereit inproceedings Emara2009a 2009 ASME paper GT2009-59948 707-716 The swirling flow velocity profiles can be strongly influenced by the outlet conditions of the combustion chamber especially at subcritical flow conditions. The effect of such changes on the mean flow or coherent structures is still unclear. It is investigated in the present work in an industrial swirl inducing burner in cold flow conditions with help of PIV. Proper orthogonal decomposition (POD) as well as acoustic measurements were used to characterize the coherent structures shed from the burner mouth. The combustor length (670, and 2020mm) and the outlet area contraction ratio (1, 0.56, 0.27, and 0.09) are varied. Major changes in the flow field are achieved when using a short combustor and the smallest contraction ratio. For this case, a central jet with streamwise velocity is added to the typical central recirculation zone. The POD analysis of the contraction ratios 1 and 0.09 for the long combustor shows that the first helical mode as well as Kelvin Helmholtz vortices are present with minor changes for both cases. At a contraction ratio of 0.09, some new structures at the jet location and near the combustor wall appear. http://link.aip.org/link/abstract/ASMECP/v2009/i48838/p707/s1 Proc. ASME Turbo Expo 2009: Power for Land, Sea, and Air (GT2009), June 8-12, Orlando, Florida, USA 9780791838495 (DVD), 978-0-7918-4883-8 (online) 10.1115/GT2009-59948 A.Emara A.Lacarelle C. O.Paschereit article Pfeifer2008b Acoustical Society of America Journal 2008 123 3405-+ 10.1121/1.2934112 C.Pfeifer J. P.Moeck L.Enghardt C. O.Paschereit inproceedings Pfeifer2008 2008 2nd International Conference on Jets, Wakes and Separated Flows, Berlin, Sep 16--19, 2008 C.Pfeifer J. P.Moeck L.Enghardt C. O.Paschereit inproceedings Pfeifer2008a 2008 Online-Veröffentlichung 34. Deutsche Jahrestagung für Akustik (DAGA 2008 - Deutsche Arbeitsgemeinschaft für Akustik, Dresden, März 2008) 978-2-9521105-4-9 C.Pfeifer J. P.Moeck L.Enghardt C. O.Paschereit inproceedings Pfeifer2008c 2008 34. Deutsche Jahrestagung für Akustik, Dresden, 10--13 März, 2008 C.Pfeifer J. P.Moeck L.Enghardt C. O.Paschereit inproceedings Pfeifer2007 2007 11th CEAS/ASC Workshop of X3-Noise, 27/28 September, 2007, Istituto Superior Tecnico, Lisbon C.Pfeifer J. P.Moeck C. O.Paschereit L.Enghardt inproceedings Paschereit2007 2007 20 638 Bundesministerium für Verkehr, Bau und Stadtentwicklung Verkehrsblatt-Verlag, Bonn Verkehrsblatt 0042-4013 C. O.Paschereit J. P.Moeck R.Engel inproceedings Moeck2007c 2007 Proceedings of the 14th International Congress on Sound and Vibration, Cairns, Australia 978-0-733-42516-5 J. P.Moeck R.Engel C. O.Paschereit