A turbulent premixed flame on fractal-grid generated turbulence

TL;DR

This study investigates how a fractal grid generates turbulence that enhances premixed flame burning rates and increases flame area, differing from standard turbulence decay patterns.

Contribution

It introduces a novel fractal grid turbulence generator and compares its effects on premixed flames to those of standard grids, highlighting increased burning rates.

Findings

Fractal grid turbulence increases flame area and burning rate.

Turbulence intensity peaks at a certain distance from the fractal grid.

Fractal turbulence differs from standard decay patterns.

Abstract

A space-filling, low blockage fractal grid is used as a novel turbulence generator in a premixed turbulent combustion experiment. In contrast to the power law decay of a standard turbulence grid, the downstream turbulence intensity of the fractal grid increases until it reaches a peak at some distance from the grid before it finally decays. The effective mesh size and the solidity are the same as those of a standard square mesh grid with which it is compared. It is found that, for the same flow rate and stoichiometry, the fractal generated turbulence enhances the burning rate and causes the flame to further increase its area. Using a flame fractal model, an attempt is made to highlight differences between the flames established at the two different turbulent fields.