Abstract: In a twin wall combustion chamber for a gas turbine engine, the outer wall has impingement holes so that compressed air surrounding the chamber can pass through the holes to impinge on the inner wall, and the inner wall has effusion holes whereby air can effuse into the combustion chamber. The number of effusion holes is greater than the number of impingement holes, the effusion-holes preferably being arranged in groups of seven, comprising six holes equi-spaced around a central seventh hole, each group having an impingement hole in a fixed positional relationship to the central hole, preferably downstream of it.

Abstract: A combustion chamber is supported in a gas turbine engine by a mounting having a first attachment assembly secured to a wall of the combustion chamber, and a second attachment assembly secured to a support structure rigidly mounted from an engine housing. The first attachment assembly includes a pair of clamp surfaces pressed by a spring to grip parallelly-spaced inner and outer surfaces of the wall. Radial thermal expansion and contraction of the wall, relative to the first attachment assembly, are accommodated by allowing radial slippage between the clamp surfaces and the gripping surfaces. The second attachment assembly includes a spring which permits the combustion chamber and the mounting to tilt relative to the support structure. By accommodating both differential radial movement and tilting, the thermal stresses in the material forming the combustion chamber are reduced.

Abstract: A gas turbine combustion includes a combustion chamber mounted within an air supply manifold. The combustion chamber preferably has a fixed downstream portion and a telescopically-movable upstream portion, a burner head provided with a fuel injector, and a primary air inlet from the manifold into the combustion chamber defined between the burner head and an upstream end of the telescopically-movable upstream portion. Movement of the upstream portion of the combustion chamber towards the burner head serves to restrict the primary air inlet while opening a secondary air inlet from the manifold into the combustion chamber downstream of the burner head. Movement of the upstream portion of the combustion chamber away from the burner head serves to open the primary air inlet while restricting the secondary air inlet.