Tomographic imaging of OH laser-induced fluorescence in laminar and turbulent jet flames

Abstract

In this paper a new approach for 3D flame structure diagnostics using tomographic laserinduced fluorescence (Tomo-LIF) of the OH radical was evaluated. The approach combined volumetric illumination with a multi-camera detection system of eight views. Single-shot measurements were performed in a methane/air premixed laminar flame and in a nonpremixed turbulent methane jet flame. 3D OH fluorescence distributions in the flames were reconstructed using the simultaneous multiplicative algebraic reconstruction technique. The tomographic measurements were compared and validated against results of OH-PLIF in the laminar flame. The effects of the experimental setup of the detection system and the size of the volumetric illumination on the quality of the tomographic reconstructions were evaluated. Results revealed that the Tomo-LIF is suitable for volumetric reconstruction of flame structures with acceptable spatial resolution and uncertainty. It was found that the number of views and their angular orientation have a strong influence on the quality and accuracy of the tomographic reconstruction while the illumination volume thickness influences mainly the spatial resolution.

The 3D Modeling System for Bioaerosol Distribution Based on Planar Laser-Induced Fluorescence

“…The VLIF technique has also been applied to image 3D concentration fields in the turbulent gaseous free jet using four complementary metal oxide semiconductor (CMOS) cameras [ 17 ]. Furthermore, Li et al have studied the reconstruction of 3D flame structures using VLIF signals from eight camera views [ 18 ].…”

Two-Dimensional Tomographic Simultaneous Multispecies Visualization—Part II: Reconstruction Accuracy

“…Optical emission tomography facilitates the detection of 2D or even 3D distributions of the chemiluminescence emission of laminar and turbulent hydrocarbon flames of any geometry. The development and application of tomographic methods for the reconstruction of flame structures in laminar and turbulent flames have gained a lot of interest in the past decade [1,2], for example, to image the distribution of chemiluminescent species or the volumetric OH-LIF signal [30][31][32][33], as well as the 3D flow field using tomographic particle image velocimetry (tomo PIV) [2,[34][35][36][37]. Floyd et al [6] and Anikin et al [3] were the first to investigate turbulent flames with optical emission tomography.…”

Chaotic Diagnostics in a Biodiesel Combustion System Using PLIF and Nonlinear Time Series Analysis▴

“…OH radical is an important intermediate product in the combustion process. It will show different colors with the progress of the combustion reaction, thus the main areas of the combustion reaction can be identified more accurately [7–9]. Gao et al.…”