Members

The National Aerospace Laboratory NLR is the central institute in the Netherlands for aerospace technology. An independent non-profit organization with a staff of about 950, NLR supports both public and private organizations.

NLR has acquired expert knowledge on gas turbine engines, and has developed test equipment and simulation software. NLR is particulary active in such areas as the evaluation of components, coatings and repair methods; computational fluid dynamics; engine noise; maintenance; and performance and emission analysis.

Service life of components
NLR has been investigating gas turbine component failures and maintenance problems since the 1970s. This work evolved into damage tolerance and life assessments, coating/repair developments and validation, and engine monitoring, to support usage control, overhaul and maintenance.

High-temperature test facilities: 

• fatigue machines capable of simulating service loads at temperatures up to 1100oC; 
• crack-growth monitoring systems; 
• creep- and creep-crack-growth testing machines; 
• vacuum and air-circulating furnaces (max. 1400oC); 
• compressor/erosion rig (600oC, 150m/s, pollutants and eroding agents); 
• burner rig (1650oC, Mach 0.75, pollutants and eroding agents); 
• numerical tools to analyse engine loads including heat transfer from hot gas to turbine parts and resulting thermo-mechanical stresses and component life.

Noise reduction
Engine noise reduction is investigated both by calculations and by tests in wind tunnels and dedicated facilities.

Environmental impact
The impact of air transport on the environment by engine noise and exhaust gas is calculated using various models and methods. Techniques for the measurement of emissions are being developed.

Performance analysis, emission prediction and simulation
NLR's main tool for off-line engine performance analysis is the Gas turbine Simulation Program (GSP), a user-friendly simulation tool running under Windows 95/98/NT. With GSP, any gas turbine configuration, including turbofan, turboshaft, turboprop, recuperated/intercooled cycle, and control system, can be modelled for both steady-state and transient simulation. Effects of operating conditions such as ambient/flight conditions, installation losses, control systems malfunctions, component deterioration and maintenance status on performance and exhaust gas emissions can be analysed in detail. For flight simulators, NLR develops real-time gas turbine models using the Turbine Engine Real Time Simulator (TERTS) environment. With the thermodynamic TERTS model, high-fidelity models are developed for both fixed-wing aircraft and helicopter simulators.