Browsing NTNU Open by Author "Hearst, R. Jason"
Now showing items 1-20 of 29
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A comparative study of the velocity and vorticity structure in pipes and boundary layers at friction Reynolds numbers up to 10^4
Zimmerman, Spencer; Philip, Jimmy; Monty, Jason P; Talamelli, A.; Marusic, Ivan; Ganapathisubramani, Bharathram; Hearst, R. Jason; Bellani, Gabriele; Baidya, Rio; Samie, Milad; Zheng, X; Dogan, Eda; Mascotelli, Lucia; Klewicki, Joe (Journal article; Peer reviewed, 2019)This study presents findings from a first-of-its-kind measurement campaign that includes simultaneous measurements of the full velocity and vorticity vectors in both pipe and boundary layer flows under matched spatial ... -
A comparison of lab-scale free rotating wind turbines and actuator disks
Helvig, Sanne de Jong (Master thesis, 2020)Planar particle image velocimetry ble gjennomført oppstrøms og i den nærliggende vaken til en roterende vindturbinmodell i laboratorieskala og aktuatordisker av samme dimensjon i en vindtunell. Den innkommende strømningen ... -
Aerodynamics of an airfoil with leading-edge icing
Vinnes, Magnus Kyrkjebø; Hearst, R. Jason (Peer reviewed; Journal article, 2021)Two super duplex stainless steels (SDSS) with different W content, namely UNS S32750 (W-free) and UNS S39274 (2.1 wt.% W), were tested in simulated crevice corrosion environments to determine the influence of W on their ... -
An experimental study of the effects of turbulence on the performance of a wind turbine model with forward and backward swept blades
Wærness, Tarald (Master thesis, 2021)Den aerodynamiske ytelsen til en vindturbinmodell med fremover- og bakoverbøyde blader ble undersøkt eksperimentelt i en vindtunnel. Et aktivt turbulensgitter produserte homogen og isotrop turbulens med turbulensintensiteter ... -
Collision of dynamic jamming fronts in a dense suspension
Peters, Ivo R.; Hearst, R. Jason; Rømcke, Olav (Peer reviewed; Journal article, 2021)Dynamic jamming is a phenomenon whereby a dense suspension switches from a fluidlike to a solidlike state when subjected to sufficient stress and deformation. Large enough systems show that this transition is accompanied ... -
A comparison of lab-scale free rotating wind turbines and actuator disks
Helvig, Sanne de Jong; Vinnes, Magnus Kyrkjebø; Segalini, Antonio; Worth, Nicholas; Hearst, R. Jason (Peer reviewed; Journal article, 2021)Planar particle image velocimetry was conducted upstream and in the near-wake of a lab-scale free-rotating wind turbine model and compared to several actuator disks with the same dimensions. The Reynolds number of the ... -
Development of a supersonic jet experiment
Hillestad, Johannes Næsset (Master thesis, 2020)Hensikten med dette prosjektet var å designe et supersonisk frijet-eksperiment. Dette eksperimentet skal brukes som en laboratorieøvelse for studenter i faget TEP4135 Fluidmekanikk 2. Mens hovedkomponentene som inngår i ... -
Experimental and numerical icing penalties of an S826 airfoil at low Reynolds numbers
Hann, Richard; Hearst, R. Jason; Sætran, Lars Roar; Bracchi, Tania (Peer reviewed; Journal article, 2020)Most icing research focuses on the high Reynolds number regime and manned aviation. Information on icing at low Reynolds numbers, as it is encountered by wind turbines and unmanned aerial vehicles, is less available, and ... -
Experimental study of channel flow with sinusoidal walls using stereo-PIV
Holum, Sander (Master thesis, 2021)Et eksperiment har blitt designet for å utforske resultatene til Brostrøm, Holum, Akselsen og Ellingsen i første omgang, og masteroppgaven kan bli sett på som en fortsettelse av dette arbeidet (Brostrøm, 2020, ... -
Experimental study of the mutual interactions between waves and tailored turbulence
Smeltzer, Benjamin Keeler; Rømcke, Olav; Hearst, R. Jason; Ellingsen, Simen Andreas Ådnøy (Peer reviewed; Journal article, 2023)When surface waves interact with ambient turbulence, the two affect each other mutually. Turbulent eddies get redirected, intensified and periodically stretched and compressed, while the waves suffer directional scattering. ... -
Flow field and performance of a vertical-axis wind turbine on model buildings
Jooss, Yannick; Bolis, Roberto; Bracchi, Tania; Hearst, R. Jason (Journal article, 2022)The placement of a scaled-down Savonius (drag) vertical-axis wind turbine on model buildings is analysed experimentally by the use of turbine performance and flow field measurements in a wind tunnel. The set-up consists ... -
The impact of upstream turbulence on a plane jet
Kamruzzaman, Md; Rømcke, Olav; Hearst, R. Jason (Peer reviewed; Journal article, 2021)The influence of upstream turbulence on the flow produced by a plane jet is investigated experimentally with hot-wire anemometry and smoke flow visualisation. An innovative active grid, where each wing can be independently ... -
In the wake of turbulence: A study on the effects of freestream turbulence on the flow around simple and complex geometries
Li, Leon (Doctoral theses at NTNU;2022:155, Doctoral thesis, 2022)With the growing demand of global energy consumption and a need to reduce pollution caused by energy production from fossil fuels, renewable sources of energy are becoming increasingly necessary for the future sustainable ... -
The influence of freestream turbulence on the temporal pressure distribution and lift of an airfoil
Li, Leon; Hearst, R. Jason (Journal article; Peer reviewed, 2021)To gain insight on how freestream turbulence (FST) affects the aerodynamics of an airfoil in a systematic manner, the present study investigates a NREL S826 airfoil subjected to seven different incoming flows with varying ... -
Optimization of a MAV helicopter for realistic flight conditions
Lolland, Filip Grevle (Master thesis, 2021)I denne masteroppgaven blir luftmotstand på små luftfarkost (MAV) helikoptre undersøkt ved bruk av numeriske strømningsberegniger(CFD) med den åpne kildekoden OpenFOAM® og med eksperimenter i den store vindtunnelen til ... -
Performance and wake of a Savonius vertical‐axis wind turbine under different incoming conditions
Aliferis, Alexander D; Jessen, Marius Stette; Bracchi, Tania; Hearst, R. Jason (Journal article; Peer reviewed, 2019)In this study, the performance, drag, and horizontal midplane wake characteristics of a vertical‐axis Savonius wind turbine are investigated experimentally. The turbine is drag driven and has a helical configuration, with ... -
PIV of the Flow Over a NREL S826 Airfoil Subjected to Different Ice Accretions
Vinnes, Magnus Kyrkjebø; Li, Leon; Hearst, R. Jason (Chapter, 2019). The results have been compared to previously acquired force measurements. For streamlined ice accretions, increased surface roughness and changes to the combined airfoil-ice geometry lead to reduced aerodynamical performance ... -
Response of the temporal turbulent boundary layer to decaying free-stream turbulence
Kozul, Melissa; Hearst, R. Jason; Monty, Jason P; Ganapathisubramani, Bharathram; Chung, Daniel (Peer reviewed; Journal article, 2020)The turbulent boundary layer developing under a turbulence-laden free stream isnumerically investigated using the temporal boundary layer framework. This studyfocuses on the interaction between the ... -
Robust features of a turbulent boundary layer subjected to high-intensity free-stream turbulence
Hearst, R. Jason; Dogan, Eda; Ganapathisubramani, Bharathram (Journal article; Peer reviewed, 2018)The influence of the large scale organisation of free-stream turbulence on a turbulent boundary layer is investigated experimentally in a wind tunnel through hot-wire measurements. An active grid is used to generate ... -
The significant impact of ribs and small-scale roughness on cylinder drag crisis
Skeide, Arne Kilvik; Bardal, Lars Morten; Oggiano, Luca; Hearst, R. Jason (Peer reviewed; Journal article, 2020)The impact of flow-normal ribs and small-scale surface roughness on the drag and vortex shedding of a circular cylinder was investigated. Three rib heights, four relative rib spacings and three different forms of microroughness ...