The flow field in a preswirled cooling air supply to a turbine rotor has been investigated by means of CFD-simulations. Coefficients for system efficiency are derived. The influences of various geometrical parameters for different configurations have been correlated with the help of appropriate coefficients. For some of the most important geometrical parameters of the coverplate receiver design recommendations have been found. For the preswirl nozzles the potential of efficiency improvement by contour design is highlighted.

Three important subjects of the physics of air systems have been chosen: Part 1: Labyrinth Seals Part 2: Rotating Holes and Two Phase Flow In these fields many new papers are available. Correlations out of the literature for the discharge coefficients of rotating holes which include the most important parameters are compared and discussed. For two phase flow simple correlations for engineering purposes are recommended, especially for vent lines of aero engines. It is concluded that much more effort is required in order to push knowledge beyond the state of current literature which is partly controversial and not comprehensive enough for computerized engineering.

The flow field in a preswirled cooling air supply to a turbine rotor has been investigated by means of CFD simulations. Coefficients for system efficiency are derived. The influences of various geometric parameters for different configurations have been correlated with the help of appropriate coefficients. For some of the most important geometric parameters of the coverplate receiver, design recommendations have been made. For the preswirl nozzles, the potential of efficiency improvement by contour design is highlighted.