PHYSICAL PROBLEM DESCRIPTION


 
 

        A model of an idealised CAN type gas turbine combustion chamber (combustor) is studied. The combustion chamber, whose dimentions are shown in Figure 1, has three sets of air inlets placed circumferentially at the combustor head to promote maximum mixing and flame stabilisation. Swirling air enters the primary combustion zone through the two sets of inlets nearest to the axis of symmetry.

        Non-swirling air enters the upper inlet and thense the primary, secondary and dilution zones via five injection holes on the liner. The liner, which separates the cooling passage from the main combustion area, is represented in the model by baffle cells. Air is assumed to be composed of 23.2% oxygen and 76.8% nitrogen, by mass, and to be at a pressur of 1 bar and temperature of 293 K.

        Only a sixty-degree sector of the combustor is simulated (Figure 2). this is achived using STARCD's cyclic boundry option, which allows the transmission of information across boundaries of this type. Gaseous fuel is supplied through an inlet at the combustor head whilist liquid fuel is injected as droplets from a single injector located on the axis. The physical properties of air and fuels and details of the individual simulations are presented in corresponding places.
 
 

Figure 1 : Combustion chamber geometry