Turbulent flame speed and thickness: phenomenology, evaluation, and application in multi-dimensional simulations

Effects of premixed flames on turbulence and turbulent scalar transport

Temperature measurements by light-scattering methods

Two-thermocouple probe for fluctuating temperature measurement in combustion : Rational estimation of mean and fluctuating time constants

The structure and radiation of an ethanol pool fire

This paper investigates the utility and accuracy of the use of fine-wire thermocouples for time resolved thermometry in turbulent flames. The problem, if course, is that there is no unique time constant in a turbulent flame with widely fluctuating temperature. An analytical formulation is presented which shows that while little error may be expected in determination of r.m.s. values of temperature, there may be a substantial error made in deduction of the mean temperature, under certain circumstances. Experimentally, in a premixed methane-air flame, a comparison is made of a time resolved compensated thermocouple measurement with a simultaneous measurement by molecular Rayleigh scattering, and the results compared with the theoretical predictions. The thermocouple, compensated through a single time constant, behaved admirably, under these conditions.

Time Resolved Thermometry by Simultaneous Thermocouple and Rayleigh Scattering Measurements in a Turbulent Flame

Measurements are described of the correlations between fluctuations in velocity, static pressure and temperature in a premixed turbulent jet flame. Two component laser velocimetry, thermocouples and a cooled microphone Pitot probe are employed along with appropriate response compensation and spectral analysis techniques to obtain the correlations from time-resolved measurements. Axial and radial surveys of the flame are presented. Evidence is found of counter-gradient diffusion in some regions of the flame. The pressure-velocity correlation is seen to be negative, and its values are comparable to those of other quantities entering the turbulent kinetic energy balance.

S. B. S. Chandran

Papers

Time Resolved Thermometry by Simultaneous Thermocouple and Rayleigh Scattering Measurements in a Turbulent Flame

Scalar-velocity correlations in a turbulent premixed flame