A STUDY OF FLAMMABILITY LEAN LIMIT FOR A BLUFF BODY STABILIZED FLAME

Abstract

An experimental investigation has been carried out on the effect of mainstream velocity, blockage ratio, and flameholder shape on the lean limit of flammability. These tests employed different blockage ratio (0.25 and 0.5) and different shapes of bluff body (cone, flat plate, cylinder and sphere). The approach stream velocity was varied up to 15 m/s. The fuel employed was natural gas. The results showed that increasing the mainstream velocity has an adverse effect on lean limit of flammability, increasing the blockage ratio widens the range of stability for cylindrical and spherical stabilizers, but has an opposite effect in case of cone and plate, and the shape of bluff body affects the lean limit of flammability through its effect on the recirculation zone shape and size.