This file was created by the Typo3 extension sevenpack version 0.7.16 --- Timezone: CET Creation date: 2023-01-27 Creation time: 08-47-43 --- Number of references 10 article Lommel2021 Indoor Air 2021 31 6 1860--1873 The SARS-CoV-2 pandemic has created a great demand for a better understanding of the spread of viruses in indoor environments. A novel measurement system consisting of one portable aerosol-emitting mannequin (emitter) and a number of portable aerosol-absorbing mannequins (recipients) was developed that can measure thespread of aerosols and droplets that potentially contain infectious viruses. The emissionof the virus from a human is simulated by using tracer particles solved in water. The recipients inhale the aerosols and droplets and quantify the level of solved tracer particles in their artificial lungs simultaneously over time. The mobile system can be arranged in a large variety of spreading scenarios in indoor environments and allows for quantification of the infection probability due to airborne virus spreading. This study shows the accuracy of the new measurement system and its ability to compare aerosol reduction measures such as regular ventilation or the use of a room air purifier. aerosol, infection transmission, measurement system, respiratory droplets, virus spread https://www.researchgate.net/publication/352223190_Novel_measurement_system_for_respiratory_aerosols_and_droplets_in_indoor_environments 10.1111/ina.12860 M.Lommel V.Froese M.Sieber M.Jentzsch T.Bierewirtz Ü.Hasirci T.Rese J.Seefeldt S.Schimek U.Kertzscher C. O.Paschereit article Yücel_2020 Journal of Engineering of gas turbines and power 2020 143 1 8 Shockless explosion combustor (SEC) is a promising concept for implementing pressure gain combustion into a conventional gas turbine cycle. This concept aims for a quasi-homogeneous auto-ignition that induces a moderate rise in pressure. Since the ignition is not triggered by an external source but driven primarily by chemical kinetics, the homogeneity of the auto-ignition is very sensitive to local perturbations in equivalence ratio, temperature, and pressure that produce undesired local premature ignition. Therefore, the precise injection of a well-defined fuel profile into a convecting air flow is crucial to ensure a quasi-homogeneous ignition of the entire mixture. The objective of this work is to demonstrate that the injected fuel profile is preserved throughout the entire measurement section. For this, two different control trajectories are investigated. Optical measurement techniques are used to illustrate the effect of turbulent transport and dispersion caused by boundary layer effects on the fuel concentration profile. Results from line-of-sight measurements by tunable diode laser absorption spectroscopy indicate that the transport of the fuel-air mixture is dominated by turbulent diffusion. However, comparisons to numerical calculations reveal the effect of dispersion toward the bounds of the fuel concentration profile. The spatially resolved distributions of the fuel concentration inside the combustor gained from acetone planar laser induced fluorescence (PLIF) replicates a typical velocity distribution of turbulent pipe flow in radial direction visualizing boundary layer effects. Comparing both methods provides deep insights into the transport processes that have an impact on the operation of the SEC. GTP-20-1504 Combustion chambers, fuels, lasers, air flow, cycles, explosions, fluorescence https://asmedigitalcollection.asme.org/gasturbinespower/article/143/1/011008/1091867/Investigation-of-the-Fuel-Distribution-in-a https://doi.org/10.1115/1.4049220 F.Yücel F.Habicht A.Jaeschke F.Lückoff C. O.Paschereit K.Oberleithner article Tschepe_2019 IMechE 2019 8 13 This paper presents the results of experimental investigations on the aerodynamic drag of roof-mounted insulators for use on low- and high-speed trains. Wind tunnel investigations at different Reynolds numbers in the subcritical, critical, and supercritical flow regime were performed, in addition to investigations using wall-mounted cylinders. Furthermore, the impact of insulator sheds made of flexible material was analyzed. For a better understanding of the aerodynamic behavior of the insulators when mounted on trains, different boundary conditions representing realistic configurations as found on the roof of trains were simulated. From the measured drag, the energy demand to overcome the aerodynamic resistance of different types of insulators was calculated. Depending on the above mentioned boundary conditions, a noticeable contribution of the insulators to the entire train’s aerodynamic drag could be observed. With flexible insulator sheds, a further increased air resistance was observed with the onset of fluttering. Similar to the cylinder, the aerodynamic behavior of the insulators depends on the respective Reynolds number. https://journals.sagepub.com/doi/10.1177/0954409719867537 10.1177/0954409719867537 TschepeJ. MaaßT.-J. NayeriC. N. PaschereitC. O. article Tschepe2019 ETR 2019 7 5 Aerodynamics referring to energy saving of modern rail vehicles and hyperloops The present article shows that aerodynamics plays an important role and has a large proportion in the rail vehicles’ energy consumption. It is about 40 – 50 % in high-speed rails or freight transports. While in the passenger transport energy savings of approximately 6 – 8 % is possible by aerodynamics measures, the potential in freight transport shall be even 8 – 10 %. In order to use this possibility sensibly, a greater consideration of the life-cycle-costs for freight and regional rails in the tendering process is necessary. TschepeJ. NayeriC. N. HechtM. article Jentzsch_2019 ARC, AIAA 2019 1 6 https://arc.aiaa.org/doi/pdf/10.2514/6.2019-2164 10.2514/6.2019-2164 M.Jentzsch H. J.Schmidt R.Woszidlo C. N.Nayeri C. O.Paschereit 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 incollection Jozefik2015 2015 127 197-211 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 Z.Jozefik A. R.Kerstein H.-J.Schmidt inproceedings Geiser2014a 2014 AIAA paper no. 2015-2476 AIAA Aviation, 13th AIAA/CEAS Aeroacoustics Conference, 16-20 June 2014, Atlanta, Georgia, USA 978-1-62410-285-1 10.2514/6.2014-2476 G.Geiser H.Nawroth A.Hosseinzadeh F.Zhang H.Bockhorn P.Habisreuther J.Janicka C. O.Paschereit W.Schroeder conference nawroth2013e 2013 Euromech Colloquium 546: Combustion Dynamics and Combustion Noise, May 13-16, 2013, Menaggio, Italy A.Hosseinzadeh H.Nawroth J.Janicka C. O.Paschereit conference nawroth2013f 2013 Euromech Colloquium 546: Combustion Dynamics and Combustion Noise, May 13-16, 2013, Menaggio, Italy G.Geiser A.Hosseinzadeh H.Nawroth F.Zhang J.Schröder J.Janicka C. O.Paschereit P.Habisreuther H.Bockhorn