Abstract: A gas-fuelled burner, especially for gas turbines powered by low calorific value fuel, is provided with restrictors to slow the incoming fuel from inlets to a similar mass mean velocity as the air provided through inlets, thereby reducing turbulence and improving combustion. The restrictors and outlet passages carrying the fuel to the combustion pre-chamber are located in vanes of a radial inlet swirler so as to alternate with the air inlets. The geometry is such that the respective flows emerge tangentially to a notional circle centered on the combustion pre-chamber of the turbine. The circle is preferably between 0.7 and 1.0 times the diameter of the actual pre-chamber. The ratio of the area of the restrictor to that of the outlet passage may lie between 1:1.1 and 1:1.7, preferably 1:1.4.

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 gas-fuelled burner, especially for gas turbines powered by low calorific value fuel, is provided with restrictors to slow the incoming fuel from inlets to a similar mass mean velocity as the air provided through inlets, thereby reducing turbulence and improving combustion. The restrictors and outlet passages carrying the fuel to the combustion pre-chamber are located in vanes of a radial inlet swirler so as to alternate with the air inlets. The geometry is such that the respective flows emerge tangentially to a notional circle centered on the combustion pre-chamber of the turbine. The circle is preferably between 0.7 and 1.0 times the diameter of the actual pre-chamber. The ratio of the area of the restrictor to that of the outlet passage may lie between 1:1.1 and 1:1.7, preferably 1:1.4.

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.