Investigation on methods to improve heat loadprediction of the SGT-600 gas turbine
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
In modern gas turbines, with the increase of inlet gas temperature to raise thework output, the importance of accurate aero-thermal analysis has become of vitalimportance. These analysis are required for temperature prediction throughoutthe turbine and to predict the thermal stresses and to estimate the cooling requiredfor each component.In the past 20 years, computational fluid dynamics (CFD) methods have becomea powerfool tool aero-thermal analysis. Due to reasons including numericallimitation, flow complications caused by blade row interactions and the effect offilm cooling, using simple steady state CFD methods may result in inaccuratepredictions. Even though employing transient simulations can improve the accuracyof the simulations, it will also greatly increase the simulation time and cost.Therefore, new methods are constantly being developed to increase the accuracywhile keeping the computational costs relatively low. Investigating some of thesedeveloped methods is one of the main purposes of this study.A simplification that has long been applied in gas turbine simulations hasbeen the absence of cooling cavities. Another part of this thesis will focus onthe effect of cooling cavities and the importance of including them in the domain.Therefore, all transient and steady state simulations have been examined for twocases; a simplified case and a detailed case. The results are then compared tothe experimental measurements to evaluate the importance of their presence inthe model. The software used to perform all simulations is the commercial codeANSYS CFX 15.The findings suggest that even though including cooling cavities would improvethe results, the simulations should be run in transient. One important finding wasthat when performing transient simulations, especially the Time Transformationmethod, not only is the pitch ratio between every subsequent blade row important,but also the pitch ratio between the stators is highly influential on the accuracyof the results.
Place, publisher, year, edition, pages
2016. , 82 p.
Gas Turbine, CFD, Turbomachinery, High Pressure Turbine, Heat Load, Time Transformation, Profile Transformation, Mixing Plane
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:liu:diva-124552ISRN: LIU-IEI-TEK-A–15/02403–SEOAI: oai:DiVA.org:liu-124552DiVA: diva2:899894
Siemens Industrial Turbomachinery AB
Subject / course
Applied Thermodynamics and Fluid Mechanics
2015-11-09, A310, Hus A, Campus Valla, Linköping, 13:15 (English)
N. Nadali, Hossein, Postdoctor
Karlsson, Matts, Professor