378
11 Power Gas Turbines
Chap. 15). The reason is realisation of large power per unit of volume and limitation of blade and vane surfaces that need cooling and hot gas protection. The work
coefficient is typically above 2 at the hub ( ψ ≈ 2.20). In Fig. 11.5, the kinematic
parameters are: ψ = 2, ϕ = v a /u = 0.6, R (degree of reaction) = 0.4. The blade speed is
typically around 350 m/s at the hub (this value comes from strength limitations). So,
the stage work is about 250 kJ/kg ( ψ ≈ 2.20). With a compressor pressure ratio until
Fig. 11.6 Rotor of the SGT6-5000F. (Courtesy Siemens Energy)
Fig. 11.5 Vane and blade profiles and velocity triangles of an axial turbine ( ψ = 2, ϕ= 0.6, R = 0.4)
11 Power Gas Turbines
Chap. 15). The reason is realisation of large power per unit of volume and limitation of blade and vane surfaces that need cooling and hot gas protection. The work
coefficient is typically above 2 at the hub ( ψ ≈ 2.20). In Fig. 11.5, the kinematic
parameters are: ψ = 2, ϕ = v a /u = 0.6, R (degree of reaction) = 0.4. The blade speed is
typically around 350 m/s at the hub (this value comes from strength limitations). So,
the stage work is about 250 kJ/kg ( ψ ≈ 2.20). With a compressor pressure ratio until
Fig. 11.6 Rotor of the SGT6-5000F. (Courtesy Siemens Energy)
Fig. 11.5 Vane and blade profiles and velocity triangles of an axial turbine ( ψ = 2, ϕ= 0.6, R = 0.4)