Combustion-induced turbulence is studied in explosions of methane/air a steel sphere with optical access. Rms turbulent velocities, u', created by four peripheral variable speed fans, were measured Particle Image Velocimetry, PIV, which indicated near-uniform, isotropic turbulence, small mean velocities. The gaseous expansion near-spherical propagating flame generated radially outwards velocity...

The design and operation of a novel optically accessible high-pressure combustion apparatus is presented. The apparatus provides optical access for the direct observation of the morphology and development of premixed reaction fronts at elevated pressures. A chamber-in-chamber design with an innovative connecting system allows for safe, constant-pressure measurements, alleviating the extreme ove...

Localized wrinkles of thin premixed flames subject to hydrodynamic instability and geometrical stretch of uniform intensity (S) are studied. A stretch-affected nonlinear and nonlocal equation, derived from an inhomogeneous Michelson-Sivashinsky equation, is used as a starting point, and pole decompositions are used as a tool. Analytical and numerical descriptions of isolated (centered or multic...

High-repetition-rate, burst-mode lasers can achieve higher energies per pulse compared with continuously pulsed systems, but the relatively few number of laser pulses in each burst has limited the temporal dynamic range of measurements in unsteady flames. A fivefold increase in the range of timescales that can be resolved by burst-mode laser-based imaging systems is reported in this work by ext...

Received ; accepted – 2 – ABSTRACT We present a statistical model which shows the influence of turbulence on a thermonuclear flame propagating in C+O white dwarf matter. Based on a Monte Carlo description of turbulence, it provides a method for investigating the physics in the so-called distributed burning regime. Using this method we perform numerical simulations of turbulent flames and show t...

A study of the structure and radiation properties of round turbulent carbon monoxide/air diffusion flames is described. Measurements of mean and fluctuating streamwise velocity and mean temperatures, concentrations of major gas species, spectral radiation intensities, and radiant heat fluxes were made. The measurements were used to evaluate predictions based on the laminar flamelet concept and ...

A Photon Monte Carlo method combined with a composition PDF method is employed to model radiative heat transfer in combustion applications. Turbulence–radiation interactions (TRIs) can be fully taken into account using the proposed method. Sandia’s Flame D and artificial flames derived from it are simulated and good agreement with experimental data is found. The effects of different TRI compone...