A comparison of component zooming simulation strategies using streamline curvature

Abstract

Typically gas turbine engine component characteristics are represented via non-dimensional maps of experimental or default data. In those cases where actual component characteristics are not available and default characteristics are used instead, conventional engine cycle simulation tools can deviate substantially at off-design and transient conditions. Similarly, when real component characteristics are available, conventional tools cannot predict the performance of the engine at other than nominal conditions satisfactorily, or account for the impact of changes in component geometry. Component zooming simulation strategies allow the performance characteristics of an isolated gas turbine engine component, resolved from a detailed, high-fidelity analysis, to be transferred to an engine system analysis carried out at a lower level of resolution. This study looked into the direct comparison of three, well-established zooming strategies utilizing a two-dimensional streamline curvature component model and a low fidelity cycle program. The validated performance of a two-dimensional, low-pressure, compressor model was integrated with a notional, two-spool, low-bypass ratio, military engine model, according to the ‘de-coupled’, ‘iterative’, and ‘fully integrated’ approaches to high-fidelity analysis. The two-dimensional model was used in the engine cycle analysis to provide a more accurate, physics- and geometry-based estimate of fan performance. Although large differences in the simulated engine performance were not observed as expected, this analysis provided a very valuable insight as to the actual speed of execution, practicality, applicability, and potential of the zooming strategies mentioned above. More importantly, this research effort established the necessary methodology and technology required towards a full, two-dimensional engine cycle analysis at an affordable computational resource in the very short term.