A5010277024- Fluid Dynamics and Turbulent Flows
- Aerodynamics and Acoustics in Jet Flows
- Wind and Air Flow Studies
- Computational Fluid Dynamics and Aerodynamics
- Combustion and flame dynamics
- Turbomachinery Performance and Optimization
- Particle Dynamics in Fluid Flows
- Gas Dynamics and Kinetic Theory
- Heat Transfer Mechanisms
- Advanced Sensor Technologies Research
- Aerodynamics and Fluid Dynamics Research
- Meteorological Phenomena and Simulations
- Cyclone Separators and Fluid Dynamics
- Rocket and propulsion systems research
- Radiative Heat Transfer Studies
- Flow Measurement and Analysis
- Advanced Aircraft Design and Technologies
- Acoustic Wave Phenomena Research
- Vehicle emissions and performance
- Advanced Combustion Engine Technologies
- Advanced Measurement and Metrology Techniques
- Optical measurement and interference techniques
- Spectroscopy and Laser Applications
- Fluid Dynamics and Vibration Analysis
- Scientific Measurement and Uncertainty Evaluation
Virginia Tech
2016-2025
Carle Foundation Hospital
2023
University of Illinois Urbana-Champaign
2023
George Washington University
2015
Applied University Research (United States)
2007-2010
This article presents a review of historical and recent developments in the understanding equilibrium non-equilibrium turbulent boundary layers at incompressible high-Reynolds number conditions. The most fundamental equations concepts are first introduced to provide basis context for material reviewed. focusses on findings concerning mean flow turbulence stress fields, as well major elements instantaneous structure. Zero pressure gradient smooth wall rough described, forming following formed...
A wide variety of models and methods for the prediction surface pressure spectrum beneath turbulent boundary layers is presented assessed. thorough review made current state art in empirical analytical models; predictions zero, adverse, favorable, nonequilibrium gradient are examined using a steady Reynolds-averaged Navier–Stokes (RANS) subset boundary-layer benchmark flow case. The existing show either an inability to adapt conditions or oversensitivity model inputs, producing nonphysical...
Abstract This paper investigates depolarization influences on detected filtered Rayleigh scattering (FRS) signals to understand, in general, when it is necessary model both the polarized and depolarized portion of signal, sufficient just portion. The effectiveness robustness spectroscopic FRS (i.e., frequency scanning method (FSM)) driven by ability accurately these across full range operating conditions for instrument. Due molecular process, polarization scattered laser light will be...
Abstract Producing a screen for use in generating an accurate, complex total pressure distortion, involves solving two distinct problems. First, the basic loss characteristics of wire mesh screens must be established. Second, interaction between multiple regions with different coefficients (as seen screen) accurately accounted for. Both tasks solved effectively to design accurate screen. For first goal, we present comprehensive data set correlations losses generated by mesh, stacked on top...
Abstract Well defined multi-property measurements are crucial for the quantification of flow within all facilities. Conventionally, these collected using physically intrusive pressure and temperature probes which introduce undesired perturbation to measurement. More recently, optical techniques have been employed supplement probe measurements, with most applications requiring particles be seeded into flow. In this contribution, advancements required integrate a molecular filtered Rayleigh...
NATO AVT-RTG-349 was dedicated to the validation of computational fluid dynamics (CFD) methods based on Reynolds-Averaged Navier-Stokes (RANS) equations and statistical turbulence models for non-equilibrium turbulent-boundary-layer flows at high Reynolds numbers. This paper describes discusses errors uncertainties arising in comparison RANS simulation results with experimental data from wind-tunnel experiments. These are associated CFD grid discretization, physical modelling, measurement...
Computational fluid dynamics was used to study the flow through a scaled, mixed-compression, high-speed inlet with rotating cowl at Mach 4.0 conditions. First, steady Reynolds-averaged Navier–Stokes computations were undertaken range of popular turbulence models including Spalart–Allmaras model, realizable cubic and Menter shear stress transport (SST) model assess impact on operating state. It found that two models, SST predicted become unstarted angle where experimental data indicated...
An experimental study of the spatial distribution integral eddy speeds in heated, supersonic free jets is presented. The physics such are immediate interest to noise-reduction approaches for tactical aircraft jet noise. In these flows, noise produced has a strong influence from speeds, particularly radiation peak directions, due Mach wave contributions. measurements obtained using time-resolved Doppler global velocimetry instrument experimentally indicate key mechanism role heating reduction...
An experimental investigation is made of smooth wall turbulent boundary layers under a family continually varying streamwise pressure gradient distributions. In general, the effects these cases on layer are found to be nonlocal and dependent upstream history effects. However, friction Reynolds number grows independent applied appears only origin layer. Special attention paid statistics fluctuating immersed surface, it that there spectral-region-dependent relationship between pressure,...
An advanced laser-Doppler measurement technique has been developed for fully resolved three-component particle position and velocity vector measurements in turbulent flows. The instrument deemed the 'comprehensive' velocimeter employs a novel optical arrangement to measure multiple-component sub-measurement-volume-scale seed positions simultaneously with of conventional velocimetry (LDV). In current paper, effectiveness resolution capabilities is considered, which allows statistics at...
There is a present need for simulating and measuring the inlet swirl distortion generated by airframe/engine system interactions to identify potential degradation in fan performance operability full-scale, ground testing environment. Efforts are described address this developing characterizing methods complex, prescribed patterns. A relevent profile was novel new method, dubbed StreamVane measured small scale tunnel using stereoscopic particle image velocimetry (PIV) as precursor generation...
It is shown experimentally that thermal nonuniformity can reduce peak supersonic jet noise while keeping static thrust levels equivalent. A generated by introducing an unheated stream on the centerline of a plenum containing heated air. This axisymmetric arrangement was studied with hypothesis convection and structure plume turbulence could be changed perturbations induced nonuniformity. The results for ideally expanded overexpanded jets indicate reductions in narrowband spectral sound...
View Video Presentation: https://doi.org/10.2514/6.2022-0696.vid This paper describes a collaborative experimental and computational study of smooth wall boundary layers in systematic family favorable adverse pressure gradients. The objective is to advance turbulence modeling these flows, particular the effects gradients that can be classified as non-equilibrium. collaboration component larger NATO AVT-349 Research Task Group. Experiments under this effort are conducted at Virginia Tech...