NLR’s primary tool for gas turbine engine performance analysis is the ‘Gas turbine Simulation Program’ (GSP), a component based modeling environment. GSP’s flexible object-oriented architecture allows steady-state and transient simulation of any gas turbine configuration using a user-friendly drag&drop interface with on-line help running under Windows95/98/NT. GSP has been used for a variety of applications such as various types of off-design performance analysis, emission calculations, control system design and diagnostics of both aircraft and industrial gas turbines. More advanced applications include analysis of recuperated turboshaft engine performance, lift-fan STOVL propulsion systems, control logic validation and analysis of thermal load calculation for hot section life consumption modeling. In this paper the GSP modeling system and object-oriented architecture are described. Examples of applications for both aircraft and industrial gas turbine performance analysis are presented.

Combined heat and power (CHP) concepts for small-scale distributed power generation offer significant potential for saving energy and reducing CO2 emissions. Microturbines are an interesting candidate for small CHP systems with advantages in terms of performance, size, noise, and costs. MTT is developing a 3 kW recuperated microturbine for micro CHP applications for large households and for truck combined APU-heating systems. To minimize costs, off-the-shelf automotive turbocharger technology has been used for the turbomachinery. During recent years, turbocharger turbomachinery performance and efficiencies have significantly increased, even for very small sizes. At the same time, efficient high-speed motor-generators have become available at relatively low prices. The development of a concept demonstrator started in May 2008. This program phase included a cycle analysis and component selection study around off-the-shelf turbomachinery, design of a custom combustor, recuperator and generator, and a test program. In this paper, results of the cycle definition, conceptual design and component matching study are presented. Next, the development of a detailed performance model is described and performance prediction results are given. Also, results of the test program and test analysis work are presented. Finally, from the conclusion of the demonstrator phase an outlook is given on the prototype design and performance, which will be the next phase of the development program.

No abstract

For gas turbine engine performance analysis, a variety of simulation tools is available. In order to minimize model development and software maintenance costs, generic gas turbine system simulation tools are required for new modeling tasks. Many modeling aspects remain engine specific however and still require large implementation efforts. One of those aspects is adaptive modeling. Therefore, an adaptive modeling functionality has been developed that can be implemented in a generic component based gas turbine environment. A single component in a system modeling environment is able to turn any new or existing model into an adaptive model without extra coding. The concept has been demonstrated in the GSP gas turbine modeling environment. An object-oriented architecture allows automatic addition of the necessary equations for the adaptation to measurement values. Using the adaptive modeling component, the user can pre-configure the adaptive model and quickly optimize gas path diagnostics capability using experimentation with field data. The resulting adaptive model can be used by maintenance engineers for diagnostics. In this paper the integration of the adaptive modeling function into a system modeling environment is described. Results of a case study on a large turbofan engine application are presented.

Gas-path-analysis (GPA) based diagnostic techniques enable health estimation of individual gas turbine components without the need for engine disassembly. Currently, the Gas turbine Simulation Program (GSP) gas path analysis tool is used at KLM Engine Services to assess component conditions of the CF6-50, CF6-80 and CFM56-7B engine families during post-overhaul performance acceptance tests. The engine condition can be much more closely followed if on-wing (i.e., in-flight) performance data are analyzed also. By reducing unnecessary maintenance due to incorrect diagnosis, maintenance costs can be reduced, safety improved and engine availability increased. Gas path analysis of on-wing performance data is different in comparison to gas path analysis with test cell data. Generally fewer performance parameters are recorded on-wing and the available data are more affected by measurement uncertainty including sensor noise, sensor bias and varying operating conditions. Consequently, this reduces the potential and validity of the diagnostic results. In collaboration with KLM Engine Services, the feasibility of gas path analysis with on-wing performance data is assessed. In this paper the results of the feasibility study are presented, together with some applications and case studies of preliminary GPA results with on-wing data.