Influence of the Mach number on the Performances of the Exit Cone after the Last Turbine Stage
Year: 2015
Type: article
Abstract: Using CFD the computational investigation of two axisymmetric and axiradial cones (diffusers) typical for the exhaust branch pipes of steam turbines was carried out in the wide range of the pressure variation at the entrance of the cones with available tip-clearance leakage. As the pressure decreased the Mach number at the cone entrance increased. It has been established that in subsonic modes the cone with continuous external by-pass without the circular blade had the flow without separation and considerably lower values of loss coefficients in comparison with the diffuser that has a projection of the internal by-pass and the circular blade. At trans-sonic rates the coefficients of total losses of both studied cones are increased reaching the values that exceed 1 and have similar values; however the coefficients of internal losses and exit velocity losses differ significantly. The obtained results allow us to extend somewhat the database for the designers that are involved in the solution of problems related to the design of outlet branch pipes for flow rates approaching the sound velocity.
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2906839915