Searched for: department%3A%22Control%255C%2B%2526%255C%2BOperations%22
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Pletzer, Johannes (author)
At speeds roughly between five and ten thousand km/h, hypersonic aircraft offer the promise of an extremely fast means of transport. Growing concerns about climate warming, however, direct attention to sustainability. This thesis focuses on atmospheric composition and radiation changes by considering a range of individual hypersonic aircraft...
doctoral thesis 2024
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Pletzer, Johannes (author), Grewe, V. (author)
Hydrogen-powered hypersonic aircraft are designed to travel in the middle stratosphere at approximately 30–40 km. These aircraft can have a considerable impact on climate-relevant species like stratospheric water vapor, ozone, and methane and thus would contribute to climate warming. The impact of hypersonic aircraft emissions on atmospheric...
journal article 2024
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Guarneri, H. (author), Verlaan, M. (author), Slobbe, D.C. (author), Veenstra, J. (author), Zijl, F. (author), Pietrzak, J.D. (author), Snellen, M. (author), Keyzer, L.M. (author), Afrasteh, Y. (author), Klees, R. (author)
Both empirical and assimilative global ocean tidal models are significantly more accurate in the deep ocean than in shelf and coastal waters. In this study, we answered whether this is due to the quality of the models used to reduce tide and surge or the general approach to treat tide and surge as two separate components of the water level...
journal article 2023
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Makaveev, M.K. (author), Snellen, M. (author), Smeur, E.J.J. (author)
This paper puts forward a novel design for an airspeed instrument aimed at small fixed-wing tail-sitter unmanned aerial vehicles. The working principle is to relate the power spectra of the wall-pressure fluctuations beneath the turbulent boundary layer present over the vehicle’s body in flight to its airspeed. The instrument consists of two...
journal article 2023
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Afrasteh, Y. (author), Slobbe, D.C. (author), Verlaan, M. (author), Klees, R. (author), Guarneri, H. (author), Keyzer, L.M. (author), Pietrzak, J.D. (author), Sacher, M. (author), Snellen, M. (author), Zijl, F. (author)
The main objective of this study is to develop and analyze an empirical noise model for model-derived coastal summer mean water levels (SMWLs) and use that to obtain a more realistic quality impact of combining hydrodynamic leveling and Unified European Leveling Network (UELN) data in realizing the European Vertical Reference System (EVRS)....
journal article 2023
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Luesutthiviboon, S. (author), Lima Pereira, L.T. (author), Ragni, D. (author), Avallone, F. (author), Snellen, M. (author)
Experimental results on trailing-edge (TE) noise from a NACA 63<sub>3</sub> –018 airfoil are presented for a chord-based Reynolds number Re<sub>c</sub> range between 2 × 10<sup>5</sup> and 3 × 10<sup>6</sup>. Far-field TE noise from the baseline airfoil with a straight TE and TE serrations is measured with varying Re<sub>c</sub>, angle of...
journal article 2023
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Jeschke, J.M. (author), Sun, D. (author), Jamshidnejad, A. (author), De Schutter, B.H.K. (author)
While Model Predictive Control (MPC) is a promising approach for network-wide control of urban traffic, the computational complexity of the, often nonlinear, online optimization procedure is too high for real-time implementations. In order to make MPC computationally efficient, this paper introduces a parameterized MPC (PMPC) approach for...
journal article 2023
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de Koning, C.M.M. (author), Jamshidnejad, A. (author)
Search-and-rescue (SaR) in unknown environments is a crucial task with life-threatening risks. SaR requires precise, optimal, and fast decisions to be made. Robots are promising candidates expected to execute various SaR tasks autonomously. While humans use heuristics to effectively deal with uncertainties of SaR, optimisation of multiple...
journal article 2023
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Domingos de Azevedo Quadros, F. (author), van Loo, Marijn (author), Snellen, M. (author), Dedoussi, I.C. (author)
Excess nitrogen deposition from anthropogenic sources of atmospheric emissions, such as agriculture and transportation, can have negative effects on natural environments. Designing effective conservation efforts requires knowledge of the contribution of individual sectors. This study utilizes a global atmospheric chemistry-transport model to...
journal article 2023
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Bai, Q. (author), Mestdagh, S.M.F. (author), Snellen, M. (author), Simons, D.G. (author)
To facilitate the conservation of seafloor habitats and planning of offshore activities, there is a growing need for mapping marine benthos in an effective and efficient way. Acoustic data acquired by multi-beam echosounders (MBES) have been extensively used for large-scale and high-resolution seafloor characterization. A deeper understanding of...
journal article 2023
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Marão Patrício, M.L. (author), Jamshidnejad, A. (author)
Interactive machines should establish and maintain meaningful social interactions with humans. Thus, they need to understand and predict the mental states and actions of humans. Based on Theory of Mind (ToM), in order to understand and interact with each other, humans develop cognitive models of one another. Our main goal is to provide a...
journal article 2023
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Mestdagh, S.M.F. (author), Bai, Q. (author), Snellen, M. (author)
Detailed knowledge of both the sedimentological and ecological characteristics of the seafloor is essential when undertaking bottom-disturbing activities, but can be a challenge to obtain. Through backscatter data at different frequencies, collected with a multi-spectral multi-beam sonar, information on the structure of both the sediment...
conference paper 2023
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Bai, Q. (author), Mestdagh, S.M.F. (author), Snellen, M. (author), Amiri Simkooei, A. (author)
Acoustic classification using single-beam and multi-beam echosounders has been widely applied in characterizing seabed sediments. Although previous studies have shown a better discrimination of fine and coarse sediments using multi-spectral echosounder data, analysis regarding comprehensive seabed sediment properties is still needed. In this...
conference paper 2023
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Afrasteh, Y. (author), Slobbe, D.C. (author), Sacher, M. (author), Verlaan, M. (author), Klees, R. (author), Guarneri, H. (author), Keyzer, L.M. (author), Pietrzak, J.D. (author), Snellen, M. (author)
All realizations of the European Vertical Reference System (EVRS) computed so far are solely based on geopotential differences obtained by spirit leveling/gravimetry. As such, there are no direct connections between height benchmarks separated by large water bodies. In this study, such connections are added by means of model-based...
journal article 2023
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Mourão Bento, H.F. (author), VanDercreek, Colin (author), Avallone, F. (author), Ragni, D. (author), Sijtsma, P. (author), Snellen, M. (author)
Aeroacoustic tests in closed wind tunnels are affected by reflections in the tunnel circuit and background noise. Reflections can be mitigated by lining the tunnel circuit. The present study investigates if lining exclusively the most accessible segment of a closed wind tunnel circuit, in particular the test section, is an approach which...
conference paper 2023
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Van der Grift, R.C. (author), Snellen, M. (author), Simons, D.G. (author)
Accurate modelling of aircraft noise in different weather conditions is crucial for the reliability of noise predictions and their application worldwide. In best-practice aircraft noise models, such as Doc.29, the change in expected sound level on the ground due to changing atmosphere is modelled with a simplified propagation calculation. The...
conference paper 2023
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Sijtsma, P. (author), Brouwer, Harry (author), Snellen, M. (author)
The fan-stator stage of turbofan engines is one of the main regions of broadband noise generation. The trend of increasing bypass ratios will make fan-stator broadband noise even more significant, as jet noise will decrease and nacelles will become shorter, thus leaving less space for liners. Within the fan-stator stage there are several...
conference paper 2023
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Luesutthiviboon, S. (author), Meirelles Pereira, L. (author), Ragni, D. (author), Avallone, F. (author), Snellen, M. (author)
The authors would like to provide the following corrections and clarifications to the article titled “Aeroacoustic Benchmarking of Trailing-edge Noise from a NACA 633–018 Airfoil with Trailing-edge Serrations” which has been published in the AIAA Journal Vol. 61, No. 1, and can be accessed online via https://doi.org/10.2514/1.J061630. The first...
journal article 2023
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Altena, A. (author), Luesutthiviboon, S. (author), de Croon, G.C.H.E. (author), Snellen, M. (author), Voskuijl, M. (author)
Due to technological advances in the drone industry, security threats induced by unmanned aerial vehicles (UAVs) are becoming more relevant. Fast and accurate localisation systems need to be designed. One approach is localisation of UAVs by their sound using acoustic techniques. So far, a systematic performance assessment of acoustic...
conference paper 2023
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Suys, T. (author), Hwang, S. (author), de Croon, G.C.H.E. (author), Remes, B.D.W. (author)
We present a novel controller for fixed-wing UAVs that enables autonomous soaring in an orographic wind field, extending flight endurance. Our method identifies soaring regions and addresses position control challenges by introducing a target gradient line (TGL) on which the UAV achieves an equilibrium soaring position, where sink rate and...
conference paper 2023
Searched for: department%3A%22Control%255C%2B%2526%255C%2BOperations%22
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