Influence of Chord Length and Inlet Boundary Layer on the Secondary Losses of Turbine Blades

Thorsten van Lil, Matthias Voigt, Konrad Vogeler

Gear compressors offer a wide range of application for probabilistic analysis. The combination of a multi shaft compressor with an extra gear, under changing conditions is creating a lot of uncertainties.
The gear's design has to meet the requirements of the compression process, as needed rotation speed of the pinions or the pinion power. These requirements lead to a specific gear with its specific losses. The examination and verification of the internal correlations is one significant objective of the project. A high efficiency of the compression process may be connected with high gear losses, or the other way around.
In addition, probabilistic simulations allow analysing the behaviour of a gear compressor during operation. It is possible to determine sensitivities of output parameters (like end pressure or efficiency) with the local environmental conditions or fabrication tolerances. However, analysing the in-operation-behaviour requires statistical information of the input parameters. To meet these concerns, distribution functions and correlations were identified through statistical analysis of measured data.
In a first step, all used computation tools for pre-designing a gear compressor have been combined in one single automated algorithm. Afterwards, this algorithm has been used for Monte-Carlo-Simulations with Latin-Hyper-Cube as the sampling method. Within this project the in-house tool ProSi is used as the probabilistic software. In a close collaboration with MAN Diesel & Turbo SE, the results will be interpreted and evaluated.

T. van Lil, M. Voigt, K. Vogeler
"Probabilistic analysis of radial gear compressors"
9th International Probabilistic Workshop, Braunschweig, 2011.