Experimentelle Untersuchungen einer axialen Strömungsmaschinenstufe mit Vor- und Nachleiträdern

FKM 1997
Issue No. 200
Project No. 143 report
Abstract:

In centrifugal pump and blower construction, adjustable guide vanes are primarily used to control specific high-speed turbomachinery, and occasionally in compressor construction. This effective but expensive type of control is contrasted with the considerably more economical control by guide vane adjustment in terms of investment and maintenance. However, guide vane misregulation (pre-rotation control) only leads to high efficiency in a small sub-range of the adjustment map. Outside this range, a rapid loss of efficiency can be observed as a result of high guide vane losses. The aim of this project was to develop new, low-loss and reliable guide vanes for the economical swirl control of axial flow machines. A comparatively simple way to avoid increased losses in the guide vanes is to use variable geometry guide vanes. These were realized in the form of aerodynamically high-quality profiles with mechanical flaps for the leading edge and in the form of a tandem trailing edge with adjustable vanes for the trailing edge. The research project was carried out in two stages. Firstly, a new design method for the realization of the new blade concepts was developed on the basis of two-dimensional grid investigations. In the second section, guide vanes for use in an axial centrifugal pump stage were created from the newly found vane profiles and investigated experimentally. By using a variable-geometry guide vane in an axial centrifugal pump stage, the operating range could be considerably extended with relatively high efficiencies in both the co- and counter-swirl range. The guide vanes used proved to be superior to conventional guide vanes in terms of both flow technology and operational reliability.
Scope of report:
157 p., 88 illus, 52 lit.
Start of work:
to a) 30.09.1993 to b) 31.08.1994
End of work:
to a) 01.01.1990 to b) 01.01.1991
Funding body:
BMWi / AIF No. 8080 and 9004
Research institute:
a) Technische Universität Braunschweig Institute of Fluid Mechanics (lead institute) Bienroder Weg 3 38106 Braunschweig
b) Technische Universität Berlin Institute of Mechanical Engineering Department of Hydraulic Fluid Machinery and Fluid Mechanics Straße des 17. Juni 135 10623 Berlin Prof. Dr.- lng.
H. Siekmann
Editor and author:
a) Dr.-lng. S. Bross zu
b) Dipl.-lng. G. Ebinger
Chairman of the working group:
Dipl. -Ing. P . Hergt KSB AB, Frankental
Chairman of the Advisory Board
Prof. Dr.-lng. habil. U. Stark: KSB AG, Frankenthai Prof. Dr.-lng. H. Kipphan Heidelberger Druckmaschinen AG, Heidelberg