Wonnam Lee

Quantitative measurements of soot particles in a laminar diffusion flame using a LII/LIS technique

Methods to investigate soot formation are studied experimentally with a co-flow burner. In this study, the soot volume fraction, soot particle diameter and number density in a laminar diffusion flame are measured using LII/LIS (laser-induced incandescence/laser-induced scattering) techniques. For the purpose of quantification, validation tests needed to be conducted before the LII/LIS techniques were applied to measure soot formation, and the development of algorithm was also required to analyse the raw data. In the present study, extinction and scattering tests with a co-flow burner were performed to acquire calibration data. From these results, we decided the optimal laser beam intensity and obtained the LII signal from the diffusion flame. In addition, the algorithm for the LII/LIS simultaneous measurement was developed and applied to this algorithm to measure the soot volume fraction in the diffusion flame.

Fuel Transfer Function Measurements in Modulated Liquid Jets

Results are presented from an experimental study of the effect of operating conditions on the fuel transfer function of a modulated liquid jet injected into a high velocity crossflow. This injection configuration is commonly used in a variety of liquid-fueled gas turbine combustion systems. The transfer function relates the rate at which fuel is injected into the crossflow to the Mie scattering intensity of droplets at a given downstream location. The time-varying rate of liquid injection into the test section is measured using a high speed rotating patternator. From a spectral analysis of the input and output functions, correlations are developed to predict the phase and gain of the fuel transfer function. Experiments are conducted over a range of jet and crossflow conditions in order to determine the effect of operating conditions on the fuel transfer function.© 2004 ASME

A Study on the Soot Particle Measurement in Co-Flow Diffusion Flame Using a Laser Diagnostics and a Thermocouple

The temperature and soot particle measurement technique in a laminar diffusion flame has been studied to investigate the characteristics of soot particle with temperature using a co-flow burner. The temperature distribution in the flame were measured by rapid insertion of a R-type thermocouple and the soot particles by LEM/LIS techniques. In these measurement, soot volume fraction, number density and soot diameters were analyzed experimentally. As a results, the spacial distributions of particle volume fraction, soot diameter, and number density are mapped throughout the flame using the Rayleigh theory for the scattering of light by particles. A laser extinction method was used to measure the soot volume fraction and laser induced scattering method was used to measure the soot particle diameter and number density. Also, we measured temperature without the effect of soot particles attached to the thermocouple junction, which is close to the nozzle. In this result, we found that upstream zone has a unstable flowing in co-flow diffusion flame and the y-axis temperature of flame has a uniform temperature distribution in the most soot volume fraction zone.