The study concerns with the interactions for LPG fuel which issues from an annulus area between two swirling air stream, one of them inside the fuel ring and the other outside it. There are six burners are classified according the air flow and the direction of flow. Each burner has two swirlers; the inner one has six swirl numbers. The outer one has six swirl numbers. The study is divided into two main parts. The first is experimental, and it concerns with the lean blow-off limits, Temperature distribution, and species concentration along the combustor center line. The second part is a numerical method; it was used to study the cold flow field inside the combustor.