GT2008-51068 IMPROVEMENT OF PERFORMANCE PREDICTION BY AUTOMATED ASSIMILATION OF GAS TURBINE COMPONENT MAPS

ABSTRACT The performance data of most Siemens heavy-duty gas turbines which have been built in the last 20 years are stored in so-called typefiles. These typefiles contain the description of the thermodynamic operating behavior for each gas turbine type using several component maps, e.g., for the compressor, the turbine and the combustion chamber. In addition to all available high-accuracy performance test results, modern IT technology enables the user to handle a tremendous volume of measured data via remote access. This allows the user to determine and to guarantee the performance of modifications and upgrades with sufficient precision, even for older gas turbine types. The method for automated generation of typefiles based on the entire volume of available data and its corresponding Matlab ® based software solution are the focus of this contribution. Although this method offers a very promising source of data from various sites, the obtainable data sets usually do not cover the entire temperature and rotational speed range that is necessary to create a map suitable for all requisite operating conditions. Thus, theoretically-based additional information combined with special extrapolation methods are necessary

Comparison of Periodic Flow Fields in a Radial Pump among CFD, PIV, and LDV Results

The interaction between the impeller and the diffuser is considered to have a strong influence on the unsteady flow in radial pumps. In this paper, the unsteady flow in a low specific speed radial diffuser pump has been simulated by the CFD code CFX-10. Both Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV) measurements have been conducted to validate the CFD results. Both the phase-averaged velocity fields and the turbulence fields obtained from different methods are presented and compared, in order to enhance the understanding of the unsteady flow caused by the relative motion between the rotating impeller and the stationary diffuser. The comparison of the results shows that PIV and LDV give nearly the same phase-averaged velocity fields, but LDV predicts the turbulence much clearer and better than PIV. CFD underestimates the turbulence level in the whole region compared with PIV and LDV but gives the same trend

Parametric study of a novel groove design for dry gas seals

This paper presents a performance analysis of a novel bidirectional groove design for dry gas seals. The scope of analysis includes the impact of important groove design parameters on the dry gas seal performance. The leakage flow and the axial stiffness and damping force coefficients are taken into account for performance assessment. For varying geometry the pressure field in the lubrication gap of the application is estimated. Based on these pressure fields the performance parameters are calculated. The utilized method to predict the fluid flow through the lubrication gap is founded on the Reynolds theory of lubrication. This two dimensional approach is based on the assumptions of a laminar viscous flow field with isothermal conditions and takes aerostatic as well as aerodynamic effects into account. The 2D approach is solved by a finite difference approximation. The aim of the contribution is to recommend geometrical parameters to ensure large static stiffness and damping force coefficients while still allowing for low seal leakage rates.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016