The Map Fitting Tool Methodology: Gas Turbine Compressor Off-Design Performance Modeling

Abstract

This paper describes the structure and the implementation of an extended parametric representation of compressor characteristics for a modern object oriented gas turbine performance simulation software (PROOSIS). The proposed methodology is the map fitting tool (MFT) methodology. The proposed MFT methodology for modeling the off design performance of gas turbine turbomachinery components (fans, compressors, and turbines) is based on a concept conceived and developed collaboratively by General Electric (GE) and NASA. This paper provides a short description of both BETA and MFT compressor maps, as well as the development of compressor component models in PROOSIS capable of using both types of maps for off design compressor performance prediction. The work presented in this paper is the outcome of a collaborative effort between Snecma Moteurs and Cranfield University as part of the European Cycle Program of the EU FP6 collaborative project—VIVACE. A detailed description of the MFT map methodology is provided with a “step-by-step” calculation procedure. Synergies between compressor MFT and compressor BETA calculations are also highlighted and a description of how these two components have been integrated into an object oriented simulation software with component hierarchy is also presented. Advanced parametric representations of fan and turbine characteristics have also been developed within PROOSIS. However, a description of these methodologies is beyond the scope of this publication. Additionally, a comparison between the advantages and disadvantages between BETA and MFT maps is an interesting debate. However, this is also beyond the scope of this paper.

Enhanced Component Analytical Solution for Performance Adaptation and Diagnostics of Gas Turbines

“…After an extensive evaluation of the existing compressor analytical solution in ref. [25,27,28] for expressing the mathematical analytical relationship between normalized rotational speed ( η c ), the most mathematically robust approach was the component analytical solution in ref. [25].…”

“…Drummond et al [26] explored the shape quantitative features of component maps and related the quantitative features with thermophysical phenomena. Jones et al [27] and Sethi et al [28] proposed a backbone compressor map fitting method using the quasi-physics-based scheme. In 2002, Zhang et al derived the explicit analytical solutions of part-load performances of a constant rotating speed single-shaft gas turbine and its cogeneration [25].…”

Local and Global Analysis of a Variable Pitch Fan Turbofan

“…Compressor map points are thereby represented in terms of their offset from the backbone line. For more details on the MFT map parameters, and their relation to the standard map parameters, see GE (1984) and Sethi et al (2013).…”

The Jet Propulsion Library: Modeling and simulation of aircraft engines

“…Other methods to capture the compressor performance characteristics are described in the literature. One example is the Map Fitting Tool (MFT) method (Sethi et al, 2013). While Jet Propulsion Library currently only implements the R-line or beta line methodology, the objectoriented structure allows for the convenient addition of such additional map format in the future.…”