A5043696262- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Particle Dynamics in Fluid Flows
- Meteorological Phenomena and Simulations
- Aerodynamics and Acoustics in Jet Flows
- Gas Dynamics and Kinetic Theory
- Heat Transfer Mechanisms
- Fluid Dynamics and Vibration Analysis
- Plant Water Relations and Carbon Dynamics
- Aerospace and Aviation Technology
- Atmospheric aerosols and clouds
- Plasma and Flow Control in Aerodynamics
- Laser-induced spectroscopy and plasma
- Mechanical Circulatory Support Devices
- Combustion and Detonation Processes
- Atmospheric and Environmental Gas Dynamics
- Air Traffic Management and Optimization
- Cardiac Structural Anomalies and Repair
- Medical Imaging Techniques and Applications
- Scientific Computing and Data Management
- Computational Fluid Dynamics and Aerodynamics
- Vacuum and Plasma Arcs
- Advanced Aircraft Design and Technologies
- Turbomachinery Performance and Optimization
- Magnetic confinement fusion research
University of Kentucky
2015-2024
Allegheny General Hospital
2009-2022
Duke University
2022
Texas A&M University – Texarkana
2020
Royal Military Academy
2020
Allegheny Health Network
2019
Culham Science Centre
2013-2017
Western University
1999-2013
Princeton University
2007-2010
University of Ottawa
2006-2008
Both the inherent intractability and complex beauty of turbulence reside in its large range physical temporal scales. This scales is captured by Reynolds number, which nature many engineering applications can be as 10(5)-10(6). Here, we report measurements over an unprecedented numbers using a unique combination high-pressure air facility new nanoscale anemometry probe. The results reveal previously unknown universal scaling behavior for turbulent velocity fluctuations, remarkably similar to...
The 2014–2016 JET results are reviewed in the light of their significance for optimising ITER research plan active and non-active operation. More than 60 h plasma operation with first wall materials successfully took place since its installation 2011. New multi-machine scaling type I-ELM divertor energy flux density to is supported by principle modelling. relevant disruption experiments modelling reported a set three mitigation valves mimicking setup. Insights L–H power threshold Deuterium...
A nanoscale thermal anemometry probe (NSTAP) has been developed to measure velocity fluctuations at ultra-small scales. The sensing element is a free-standing platinum wire, 100 nm × 2 μm 60 μm, suspended between two current-carrying contacts and the sensor an order of magnitude smaller than presently available commercial hot wires. constructed using standard semiconductor MEMS manufacturing methods, which enables many probes be manufactured simultaneously. Measurements were performed in...
Abstract Measurements of the streamwise component turbulent fluctuations in fully developed smooth and rough pipe flow are presented over an unprecedented Reynolds number range. For numbers $R{e}_{\tau } \gt 20\hspace{0.167em} 000$ , stress closely follows scaling mean velocity profile, independent roughness, same spatial extent. This observation extends findings a logarithmic law turbulence as reported by Hultmark, Vallikivi & Smits ( Phys. Rev. Lett. vol. 108, 2012) to include flows....
Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of development and application these systems, improving knowledge best practices for accurate measurement is critical achieving scientific goals. We present results from an intercomparison data Lower Atmospheric Process Studies at Elevation-a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. evaluate a total 38 individual sUAS with 23 unique sensor platform...
ABSTRACT Because unmanned aircraft systems (UAS) offer new perspectives on the atmosphere, their use in atmospheric science is expanding rapidly. In support of this growth, International Society for Atmospheric Research Using Remotely-Piloted Aircraft (ISARRA) has been developed and convened annual meetings “flight weeks.” The 2018 flight week, dubbed Lower Profiling Studies at Elevation–A Team Experiment (LAPSE-RATE), involved a 1-week deployment to Colorado’s San Luis Valley. Between 14 20...
A correction for streamwise Reynolds stress data acquired with insufficient spatial resolution is proposed wall-bounded flows. The method based on the attached eddy hypothesis to account filtering effects at all wall-normal positions. This analysis reveals that outside near-wall region effect scales inversely distance from wall, in contrast commonly assumed scaling viscous length scale. new formulation shown work very well taken over a wide range of numbers and wire lengths.
Abstract Five separate data sets on the mean velocity distributions in Princeton University/ONR Superpipe are used to establish best estimate for value of von Kármán’s constant flow a fully developed, hydraulically smooth pipe. The profiles were taken using Pitot tubes, conventional hot wires and nanoscale thermal anemometry probes. was found vary significantly due measurement uncertainties velocity, friction wall distance, number points included analysis. Kármán turbulent pipe is be $0.40...
Abstract Well-resolved streamwise velocity spectra are reported for smooth- and rough-wall turbulent pipe flow over a large range of Reynolds numbers. The turbulence structure far from the wall is seen to be unaffected by roughness, in accordance with Townsend’s number similarity hypothesis. Moreover, energy within region follow classical inner outer scaling behaviour. While an overlap between two scalings associated ${ k}_{x}^{- 1} $ law observed near ${R}^{+ } \approx 3000$ , behaviour...
Abstract This article reports on one component of a larger study measurement the zero-pressure-gradient turbulent flat plate boundary layer, in which detailed investigation was conducted suite corrections required for mean velocity measurements performed using Pitot tubes. In particular, shear across tube and blockage effects occur when is close proximity to wall were investigated from tubes five different diameters, two facilities, at Reynolds numbers ranging ${\mathit{Re}}_{\theta } =...
This paper describes the components and usage of an unmanned aerial vehicle developed for measuring turbulence in atmospheric boundary layer. A method computing time-dependent wind speed from a moving velocity sensor data is provided. The physical system built to implement this using five-hole probe described along with approach used combine different on-board sensors allow extraction as function time position. demonstrated three flights two vehicles (UAVs) lower layer during transition...
Velocity measurements were performed in a wing-tip vortex wandering free-stream turbulence using two four-wire hot-wire probes. Vortex was well represented by bi-normal probability density with increasing resulting increased amplitude of wandering. The most dominant wavelength found to remain unaffected conditions. Two-point velocity used reconstruct the profile frame reference vortex. Increasing intensity increase rate decay peak circumferential while radial location this remained...
New measurements of the streamwise component turbulence intensity in a fully developed pipe flow at Reynolds numbers up to 145 000 indicate that magnitude near-wall peak is invariant with number location and magnitude. The results agree previous data have sufficient spatial resolution avoid filtering effects, but stand contrast similar obtained boundary layers, where displays prominent dependence, although its position fixed same as flow. This indicates interaction between inner outer...
Multi-point velocity measurements have been performed in turbulent pipe flow at Re D = 1.5 × 10 5 and combined with cross-spectral proper orthogonal decomposition analysis to elucidate information on the structure of large- very-large-scale motions outer layer wall-bounded flows. The results indicate that large-scale (LSM) may be composed detached eddies a wide range azimuthal scales, whereas logarithmic they are attached. (VLSM) large radial concentrated around single mode make smaller...
Two-point hot-wire measurements of streamwise velocity were performed in the logarithmic and wake regions turbulent pipe flow for Reynolds numbers, based on diameter, ranging from 7.6 × 10 4 to 8.3 6 at four wall-normal positions with azimuthal probe separation. The correlations found be consistent presence very large-scale coherent low-wavenumber, low-momentum fluid observed previous studies wall-bounded flows independent changing number surface roughness effects. At edge layer scale...
Concentrations of airborne chemical and biological agents from a hazardous release are not spread uniformly. Instead, there regions higher concentration, in part due to local atmospheric flow conditions which can attract agents. We equipped ground station two rotary-wing unmanned aircraft systems (UASs) with ultrasonic anemometers. Flights reported here were conducted 10 15 m above level (AGL) at the Leach Airfield San Luis Valley, Colorado as Lower Atmospheric Process Studies Elevation—a...
Abstract Uncrewed aircraft system (UAS) observations collected during the 2018 Lower Atmospheric Process Studies at Elevation—a Remotely Piloted Aircraft Team Experiment (LAPSE-RATE) field campaign were assimilated into a high-resolution configuration of Weather Research and Forecasting Model using an ensemble Kalman filter. The benefit UAS was assessed for terrain-driven (drainage upvalley) flow event that occurred within Colorado’s San Luis Valley (SLV) independent observations. analysis...
Abstract. Unmanned aircraft systems (UASs) offer innovative capabilities for providing new perspectives on the atmosphere, and therefore atmospheric scientists are rapidly expanding their use, particularly studying planetary boundary layer. In support of this expansion, from 14 to 20 July 2018 International Society Atmospheric Research using Remotely piloted Aircraft (ISARRA) hosted a community flight week, dubbed Lower Profiling Studies at Elevation – Remotely-piloted Team Experiment...
The three-dimensional nature of turbulent vortex shedding from a square cylinder in the vicinity solid wall is investigated for Reynolds number 18 900 as function gap height, S/D. Spanwise surface pressure measurements on faces and are complemented by velocimetry data. It observed that parallel oblique modes arise naturally. dislocations clearly related to variations angle. Dislocations occur with increasing probability height decreased S/D≈0.7. strongly associated Type A instabilities...