3D Instantaneous Reconstruction of Turbulent Industrial Flames Using Computed Tomography of Chemiluminescence (CTC)

A Unterberger,K Mohri,M Röder,A Giese,A Kempf,A Al-Halbouni

doi:10.1155/2018/5373829

Abstract

Computed Tomography of Chemiluminescence (CTC) was used to reconstruct the instantaneous three-dimensional (3D) chemiluminescence field of a high-power industrial flame, which was made optically accessible, for the first time. The reconstruction used 24 projections that were measured simultaneously, in one plane and equiangularly spaced within a total fan angle of 172.5°. The 3D results were examined by plotting both vertical and horizontal slices, revealing highly wrinkled structures with good clarity. The results presented are one of a series of experimental demonstrations of CTC applications to turbulent gaseous flames. The work reveals the potential to use any kind of luminescence measurement, such as emission from heated particles in coal-fired flames, for analysis of the flame shape directly in 3D.

Highlights

The use of fossil fuels such as coal remains to be the main source in today’s power generation and likely to continue being so for the coming decades
Our focus on gaseous flames so far demonstrates the capability of Computed Tomography of Chemiluminescence (CTC) and prepares the technique for application to coal-fired combustion where emissions from heated coal particles will be used for volumetric flame reconstructions [6]
The spectral density detected on the camera pixel corresponds to the sum of the light emitted along the light ray path through the probe volume. This is based on the fundamental radiative transfer equation (RTE), which relates the change in radiation intensity along a ray path to local absorption and volume emission [11, 12]

Summary

Introduction

The use of fossil fuels such as coal remains to be the main source in today’s power generation and likely to continue being so for the coming decades. It is possible to use complex experiments constituting highspeed cameras, lasers, and rotating mirrors, to obtain timeresolved 3D information about species and temperature from multiple quasi-instantaneous light-sheet measurements [1, 2]. This approach is very expensive and challenging. Our focus on gaseous flames so far demonstrates the capability of CTC and prepares the technique for application to coal-fired combustion where emissions from heated coal particles will be used for volumetric flame reconstructions [6]. The CTC was first developed to reconstruct the instantaneous chemiluminescence field of gaseous flames by Floyd [7], and was proven to work using commodity cameras. The setup was completed around the burner and flame reconstructions were achieved, revealing information about the flame shape, which are presented in this paper, for the first time

The CTC Technique

The Experimental Setup

Conclusions

Disclosure