The Impact of Surface Roughness on Transonic Compressor Performance
Ladda ner
Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Applied mechanics (MPAME), MSc
Publicerad
2015
Författare
Chinnaswamy, Sathyavanan
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The increasing necessity for highly efficient engines and flow emission standards has steered the need for research into more efficient design and optimization of gas turbines. Surface roughness in the blades of compressors and turbines is one of the factors causing performance deterioration in gas turbines. This study involves the investigation of surface roughness effects on the performance of a research compressor stage through numerical simulations in a commercial CFD code, ANSYS CFX. An initial numerical study on a NACA airfoil was conducted with roughness and validated with the experimental data. It is followed by the implementation of uniform sand grain roughness over the rotor and stator blades of the compressor stage using the surface roughness model available in ANSYS CFX. Two different cases, one with roughness on the rotor and one with roughness on the stator and rotor combination were done. The results from the study shows the reduction in the main performance parameters such as pressure ratio, efficiency and mass flow in the compressor stage. The flow calculations shows an increase in blockage of the flow in the stage with an increase in surface roughness on the blades. Surface streamlines shows the influence of surface roughness on the separation over the suction side of the stator and the regions near the hub in the rotor.
Beskrivning
Ämne/nyckelord
Maskinteknik , Energi , Grundläggande vetenskaper , Hållbar utveckling , Rymd- och flygteknik , Strömningsmekanik och akustik , Mechanical Engineering , Energy , Basic Sciences , Sustainable Development , Aerospace Engineering , Fluid Mechanics and Acoustics