Turbulence characteristics of a fan-stirred combustion vessel

Flame surface properties of premixed flames in isotropic turbulence: Measurements and numerical simulations

“…2; nevertheless, experimental uncertainties (95 % confidence) of z are less than 20%. A correlation of present measurements, and an earlier correlation of Fansler and Groff [27], also are shown on the plot. points, with u' and v' being velocity fluctuations along and normal to the x axis.…”

“…Results were obtained at the center as well as +30 mm from the center of the chamber at pressures of 1 and 3 atm. A correlation for ~' at the center of the chamber for pressures of 1, 3, and 5 atm, reported by Fansler and Groff [27], is also shown on the plot. The two sets of measurements are in good agreement, yielding a nearly linear increase of ~' with fan speed and relatively small effects of pressure.…”

“…Velocity statistics of the unburned gas were measured to provide parameters needed to numerically simulate the velocity field. Fansler and Groff [27] also measured turbulence properties in this combustion chamber and their results will be compared with present findings wherever possible.…”

“…Finally, ~'/~' was generally within 10% of unity over the same region, indicating reasonably isotropic turbulence. Probability density functions of velocity fluctuations, u' and v', also satisfied Gaussian probability density functions within experimental uncertainties [25,27]. Temporal power spectral densities of vertical fluctuations are plotted as a function of frequency in Fig.…”

“…The fans directed their flow toward the walls of the chamber and were driven by variable-speed synchronous motors. Fansler and Groff [27] show that this arrangement provides an isotropic flow field in the central region of the chamber.…”