Category: Axial Flow Air Compressors

The degree of reaction, Rd, is defined as the ratio of pressure rise in the rotor blades to the pressure rise in the compressor stage. Pressure rise in the rotor blades  Pressure rise in the compressor stage For 50% degree of reaction,  From Eqs (15.8) and (15.9), we have Therefore, with 50% degree of reaction, the blades are symmetrical.…

Figure 15.5 shows the velocity triangles for one stage of an axial flow compressor. All angles are measured from the axial direction. The blade velocity u is taken to be same at blade entry and exit as the air enters and leaves the blades at almost equal radii. Due to the diffusion process in the moving blades, vr2 < vr1 but va2 > va1. The…

When an object is placed within a fluid stream, a force is exerted on the object which may be inclined to the flow direction. The component of this force parallel to the direction of flow is called the drag and the normal component is called the lift, as shown in Fig. 15.2. Consider an aerofoil section…

The axial compressor is generally driven by an internal combustion engine or a turbine. The work input to the rotor shaft is transferred by the rotor moving blades to the air, thus accelerating it. The space between the moving blades form diffuser passages so that the velocity of air relative to the blades is decreased…

The cross-section of a typical axial flow compressor is shown in Fig. 15.1. It consists of adjacent rows of moving and fixed blades. The moving blades are mounted on the rotating drum and the fixed blades are fixed to the casing or stator. One stage of the compressor comprises a row of moving blades, followed by…

In an axial flow compressor, the air flows throughout the compressor parallel to its axis. Axial flow compressor has many merits over centrifugal compressor and is particularly suitable for super charging of internal combustion engines, turbojets, and gas turbines.