Comprehensive study of flow instabilities and sound wave generation in the wake of perforated plates.

Modern gas-fired heating systems for household applications make increasingly use of forced draft surface combustion because of their low-NOx emission capability. With surface combustion, a premixed mixture of gas and air is forced through a perforated plate or a metal/ceramic fiber mat, and the flame is spread out on the downstream side of the surface. Although this technique yields very low NOx emission, its wide spread application is limited by the occurrence of thermo-acoustic instability.This project proposes a study of a new abatement technique for perforated plate burners.When a fluid flows through a perforated plate with high solidity, flow instabilities occur in the immediate wake of the perforated plate. These flow instabilities manifest themselves through the occurrence of abrupt, high-amplitude fluctuations of the axial through-flow velocity. There exists strong evidence that these velocity fluctuations are responsible for the noise problem. We propose to study the physics behind these flow instabilities.

Keywords:Flow mechanics

Disciplines:Mechanics, Thermodynamics, Electrical power engineering, Energy generation, conversion and storage engineering