Volumetric imaging of turbulent reactive flows at kHz based on computed tomography

Li, Xuesong; Ma, Lin

doi:10.1364/oe.22.004768

Cited by 65 publications

(25 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two major factors causing such disagreement included the reconstruction algorithm and measurement error caused by pulse-to-pulse variation of the laser intensity. First, according to our numerical simulations using phantoms, the reconstruction algorithm was able to solve the VLIF problem within 1~2% accuracy with error-free projections (here accuracy was defined following [24] as the overall difference between the reconstructed distribution and the phantom relative to the overall magnitude of the phantom). The current algorithm was based on the iteration of the ART, and alternative algorithms (e.g., based on simulated annealing [31,32]) are being explored to improve the reconstruction accuracy.…”

Section: Tomographic Reconstructionmentioning

confidence: 99%

“…Because the LIF signals are generated volumetrically, the images captured by the cameras are line-of-sight integrated (which are termed projections). A tomographic algorithm [22][23][24][25][26][27] is then employed to reconstruct the 3D distribution of the target species based on such projection measurements, as elaborated in Sections 2 immediately below.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Single-shot volumetric laser induced fluorescence (VLIF) measurements in turbulent flows seeded with iodine

Wu¹,

Xu²,

Lei³

et al. 2015

Opt. Express

Self Cite

View full text Add to dashboard Cite

This work reports the experimental demonstration of single-shot visualization of turbulent flows in all three spatial dimensions (3D) based on volumetric laser induced fluorescence (VLIF). The measurements were performed based on the LIF signal of iodine (I 2 ) vapor seeded in the flow. In contrast to established planar LIF (PLIF) technique, the VLIF technique excited the seeded I 2 vapor volumetrically by a thick laser slab. The volumetric LIF signals emitted were then simultaneously collected by a total of five cameras from five different orientations, based on which a 3D tomographic reconstruction was performed to obtain the 3D distribution of the I 2 vapor in the target flow. Single-shot measurements (with a measurement duration of a few ns) were demonstrated in a 50 mm × 50 mm × 50 mm volume with a nominal spatial resolution of 0.42 mm and an actual resolution of ~0.71 mm in all three dimensions (corresponding to a total of 120 × 120 × 120 voxels). 249-256 (1996). 18. M. Zhang, J. Wang, W. Jin, Z. Huang, H. Kobayashi, and L. Ma, "Estimation of 3D flame surface density and global fuel consumption rate from 2D PLIF images of turbulent premixed flame," Combust.

show abstract

Section: Tomographic Reconstructionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Single-shot volumetric laser induced fluorescence (VLIF) measurements in turbulent flows seeded with iodine

Wu¹,

Xu²,

Lei³

et al. 2015

Opt. Express

Self Cite

View full text Add to dashboard Cite

show abstract

“…The authors believe that the tomography approach will play a significant role in pursuing the ultimate goal of performing multi-dimension optical diagnostics and that comparing with other approaches is also crucial. 243 This chapter will cover several key perspectives of the tomography approach such as reconstruction algorithms, experimental apparatus, and tomography applications in combustions.…”

Section: Tomography Techniquesmentioning

confidence: 99%

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

Ehn

Zhu

et al. 2017

Appl Spectrosc

Self Cite

View full text Add to dashboard Cite

Gaining information of species, temperature, and velocity distributions in turbulent combustion and high-speed reactive flows is challenging, particularly for conducting measurements without influencing the experimental object itself. The use of optical and spectroscopic techniques, and in particular laser-based diagnostics, has shown outstanding abilities for performing non-intrusive in situ diagnostics. The development of instrumentation, such as robust lasers with high pulse energy, ultra-short pulse duration, and high repetition rate along with digitized cameras exhibiting high sensitivity, large dynamic range, and frame rates on the order of MHz, has opened up for temporally and spatially resolved volumetric measurements of extreme dynamics and complexities. The aim of this article is to present selected important laser-based techniques for gas-phase diagnostics focusing on their applications in combustion and aerospace engineering. Applicable laser-based techniques for investigations of turbulent flows and combustion such as planar laser-induced fluorescence, Raman and Rayleigh scattering, coherent anti-Stokes Raman scattering, laser-induced grating scattering, particle image velocimetry, laser Doppler anemometry, and tomographic imaging are reviewed and described with some background physics. In addition, demands on instrumentation are further discussed to give insight in the possibilities that are offered by laser flow diagnostics.

show abstract

“…Similar to the scanning approach, the tomography approach can be used in combination with a range of signal generation mechanisms, ranging from absorption spectroscopy [16,17] , Mie scattering [18,19] , chemiluminescence [20][21][22] , and particle imaging velocimetry (PIV) [23] . In contrast to the scanning approach, higher temporal resolution (up to 20 kHz [24] ) in larger measurement volumes (on the order of 10 × 10 × 10 cm 3 [20] ) have been reported for the tomography approach because these techniques do not require the physical scanning of the illumination laser sheet. A comprehensive comparison of all the techniques in both categories, though highly valuable in the authors' opinion, is beyond the scope of the current paper.…”

Section: Introductionmentioning

confidence: 99%

3D flame topography and curvature measurements at 5 kHz on a premixed turbulent Bunsen flame

Lei

et al. 2016

Combustion and Flame

Self Cite

View full text Add to dashboard Cite

a b s t r a c tThis work reports the measurements of three-dimensional (3D) flame topography and curvature of a premixed turbulent Bunsen flame at a rate of 5 kHz, using a technique combining chemiluminescence and tomography. Line-of-sight images of chemiluminescence (termed projections ) of the target flame were recorded by six cameras from different orientations simultaneously at 5 kHz. Based on these projections, a tomography algorithm reconstructed the 3D flame structure, based on which 3D curvature was then calculated. Due to the 3D nature of the data, statistics of flame properties can then be extracted both in temporal and spatial domains. Probability density function (PDF) of flame topography was extracted from a series of 3D measurements, and the PDFs of the flame at different spatial locations were examined. Furthermore, the instantaneously measured 3D flame topography also enabled the calculation of 3D flame curvature (or 2D curvature along an arbitrary orientation). The PDFs of curvature in 2D and 3D were then extracted and compared. These results provide quantification of the flame surface shape in 3D (cylindrical, elliptic, or hyperbolic), illustrating the utility of 3D diagnostics to fully resolve the dynamics of turbulent flames.

show abstract

Volumetric imaging of turbulent reactive flows at kHz based on computed tomography

Cited by 65 publications

References 29 publications

Single-shot volumetric laser induced fluorescence (VLIF) measurements in turbulent flows seeded with iodine

Single-shot volumetric laser induced fluorescence (VLIF) measurements in turbulent flows seeded with iodine

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

3D flame topography and curvature measurements at 5 kHz on a premixed turbulent Bunsen flame

Contact Info

Product

Resources

About