PIV and Rotational Raman-Based Temperature Measurements for CFD Validation of a Perforated Plate Cooling Flow: Part I

Wernet, Mark P.; Georgiadis, Nicholas J.; Locke, Randy J.; Thurman, Douglas R.; Poinsatte, Philip E.

doi:10.2514/6.2020-1230

Cited by 13 publications

(2 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A video demonstration of the RT-BOS system is available (stacks.iop.org/MST/31/017001/mmedia). Figure 3 contains a screenshot of the RT_BOS screen, showing a processed image from a heated supersonic jet flow over a film cooled plate experiment [10]. The background speckle pattern on the 4K monitor does not fill the entire 2448 × 2048 pixel camera field-of-view and only a region-of-interest of the image is processed.…”

Section: Real-time Bos Programmentioning

confidence: 99%

Real-time background oriented schlieren with self-illuminated speckle background

Wernet¹

2019

Meas. Sci. Technol.

View full text Add to dashboard Cite

Background oriented schlieren (BOS) is a widely used technique that provides density gradient information in flow fields of interest. Raw BOS image data provide little, if any, visual indication of the density gradients in the flow. The acquired image data must be processed off-line after the test is completed, providing no indication of the quality of the BOS setup nor any feedback on the operational success of the test. The use of graphical processing units (GPUs) enables real-time acquisition, processing and display of BOS image data. In addition to real-time BOS processing, self-illuminated speckle backgrounds are implemented by incorporating a 4 K monitor into the BOS system. The combination of the real-time processing and a computer controlled/generated background speckle pattern enables self-optimization of the BOS system both prior and during testing.

show abstract

Section: Real-time Bos Programmentioning

confidence: 99%

Real-time background oriented schlieren with self-illuminated speckle background

Wernet¹

2019

Meas. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Vibrational Raman is ineffective in low temperature regimes due to the lack of the anti-Stokes bands; however, pure rotational Raman spectroscopy, which is not dependent upon anti-Stokes lines, has been used to interrogate expanding supersonic flows of CO 2 for measuring temperature (Maté et al 1998). Rotationally resolved Raman has more recently been used to acquire mean and rms temperature measurements in high-temperature flows, from subsonic to supersonic speeds in harsh real-world test facilities (Locke et al 2017;Wernet et al 2018Wernet et al , 2019Wernet et al , 2020. Rotationally resolved Raman scattering is the only technique which is relatively simple to setup/align and robust against the hostile environments found in real-world aerospace simulation facilities; therefore, it was the technique of choice for measuring the gas temperatures in supersonic jet flows of interest.…”

Section: Introductionmentioning

confidence: 99%

Raman temperature and density measurements in supersonic jets

Wernet

Georgiadis

Locke³

2021

Exp Fluids

Self Cite

View full text Add to dashboard Cite

Prediction of flow-field properties in supersonic jets using computational fluid dynamics (CFD) code predictions has become routine; however, obtaining accurate solutions becomes more challenging when there is a significant temperature difference between the jet core and the ambient air and/or compressibility effects are significant. Benchmark sets of flow field property data are required in order to assess current CFD capabilities and develop better modeling approaches for these turbulent flow fields where accurate calculation of temperatures and turbulent heat flux is important. Particle Image Velocimetry, spontaneous rotational Raman scattering spectroscopy, and Background-Oriented Schlieren (BOS) have been previously used to acquire measurements of the mean and root-mean-square (rms) velocities, the mean and rms gas temperatures, and density gradients in subsonic jet flows and film cooling flows. In this work, the ability to measure density is added to the list of measurands available using the acquired Raman spectra. The suite of measurement techniques are now applied to supersonic jet flows. The computation of the local gas pressure in the potential core of an over-expanded jet is demonstrated using the Raman measured gas temperature and density. Additionally, a unique density feature in temperature matched, perfectly expanded jet flow shear layers identified using BOS was verified using the Raman measurement technique. These non-intrusive flow measurements are compared against RANS predictions of the supersonic jet flow properties as a means of assessing their prediction accuracy. Graphic abstract

show abstract

Application of Planar Laser Rayleigh Scattering for Measurement of Gas Temperature Distributions in Effusion Jet Cooled Panels Exposed to High Temperatures

Grasso

Snyder

Cetegen

2021

Journal of Heat Transfer

View full text Add to dashboard Cite

This experimental study examines the use of planar laser Rayleigh scattering to measure instantaneous gas temperature distributions at different heights above the surface of an effusion cooled plate. An experimental test rig was used to model combustor conditions with a bulk crossflow temperature of 1500 K. Carbon dioxide was used as coolant at multiple blowing ratios ranging from 1.12 to 11.1. A "temperature-pegging" methodology was used to process Rayleigh light scattering images to create high resolution and accurate temperature images at heights of 2, 2.75, and 3.5 mm above the surface of a prototypical effusion plate. Measured temperature distributions were used to calculate root mean square (RMS) distributions, and were also converted to film effectiveness maps based on the upstream crossflow gas and effusion coolant temperatures. It is found that film cooling region spreads upstream with increasing effusion jet blowing ratio parameter. The root mean square (RMS) deviation of gas temperatures over each measurement plane show that the RMS fluctuations are low inside and outside the effusion film, but are high near the film edge. At a given height above the effusion panel, the RMS fluctuations decrease in the film region with increasing blowing ratio. Film effectiveness follows similar trends with high film effectiveness region expanding with increasing effusion jet blowing ratios.

show abstract

PIV and Rotational Raman-Based Temperature Measurements for CFD Validation of a Perforated Plate Cooling Flow: Part I

Cited by 13 publications

References 33 publications

Real-time background oriented schlieren with self-illuminated speckle background

Real-time background oriented schlieren with self-illuminated speckle background

Raman temperature and density measurements in supersonic jets

Application of Planar Laser Rayleigh Scattering for Measurement of Gas Temperature Distributions in Effusion Jet Cooled Panels Exposed to High Temperatures

Contact Info

Product

Resources

About