In this paper, we present a detailed experimental study of turbulence chemistry interactions in the ‘‘DLR_B’’ turbulent jet diffusion flame. The flame operates on mixtures of CH4, H2, and N2 in the fuel stream at Re = 22,800 and is a target flame within the TNF workshop. Extinction and re-ignition events can be tracked in real time and related to the underlying flow field phenomena and temperat...

Sub-Doppler excitation spectroscopy in a collimated cold supersonic beam of 5% NO seeded in argon has been performed with a spectral resolution down to 10 MHz for four vibronic bands within the perturbed B ?X A system of NO . The rotational temperature of about 15 K achieved by adiabatic cooling allows the separation of closely lying vibronic bands which overlap in absorption spectra ...

We explore the detailed structure of heat release and the energy budget for a freely-propagating lean, premixed hydrogen flame. At lean conditions, the flame is thermodiffusively unstable and spontaneously develops the cellular burning structures, characteristic of this type of flame. The instabilities in the system saturate quickly, resulting in robust, slowly evolving cellular burning feature...

This paper presents an experimental study of the influence heat losses on onset thermoacoustic instabilities in methane–air premixed flames propagating a horizontal tube diameter, $D = 10$ mm. Flames are ignited at open end and propagate towards closed undergoing strong oscillations different features owing to interaction with acoustic waves. The frequency oscillation its axial location control...

A novel approach to simultaneously measure the translational temperature, bulk velocity, and density in gases by collecting, referencing, and analyzing nanosecond time-scale Rayleigh scattered light from molecules is described. A narrow-band pulsed laser source is used to probe two largely separated measurement locations, one of which is used for reference. The elastically scattered photons con...

Combustion instabilities in gas turbine has been a major setback in the quest for efficient and clean combustion. Accurate characterisation and prediction of these disturbances is required to suppress them either at the design stage or in a close loop control when the system is in operation. The use of flame transfer functions has been a common approach in different literatures. Flame temperatu...

Premixed methane-air mixture is introduced at the center of two parallel circular quartz plates separated by a millimeter scale distance (<or= 5mm). Two plates are heated with an external heater to create a positive temperature gradient condition along the flow direction. The combustion characteristics of lean methane-air mixtures are investigated at phi=0.67 and phi=0.85 in the laminar flow re...

The effects of strain rate and temperature on the dynamic behavior of Fe-based high temperature alloy was studied. The strain rates were 0.001-12,000 s(-1), at temperatures ranging from room temperature to 800 °C. A phenomenological constitutive model (Power-Law constitutive model) was proposed considering adiabatic temperature rise and accurate material thermal physical properties. During whic...

The nature of the thermodynamic behavior of Type I superconductor particles, having a cross section less than the Ginzburg-Landau temperature dependent coherence length, ξ(T), is discussed for magnetic field induced adiabatic phase transitions from the superconductive state to the normal state. Argument is advanced supporting the view that when the adiabatic magnetocaloric process is applied to...