STAC4T Streamfunction Throughflow Analysis Code for Turbines [Developer Guide]

Kurzfassung

This report describes the application of the 2D throughflow program STAC4T and provides many details and background information for future developers. A more comprehensive overview specifically designated for users of the program is given in the accompanying report DLR-IB 225 - 2015 A 02 A. In contrast to the throughflow program SLC4T, which is based on the streamline curvature method and capable to compute supersonic flows, this program is based on the matrix or streamfunction method. Thus, backflows as they occur in diffusors or at part load can be computed. The program computes the axisymmetric flow quantities at finite elements along the S2m plane through the turbine. Currently, only the Traupel loss correlations are implemented. Pre-processing tools for grid generation and an interface with DLR's BladeGenerator are explained as well as output options, which can also be used as inital solution for TRACE. Due to it's fast computation speed, the computations of complete performance maps is possible and can be used for optimizations of turbine designs for a broad performance range.