TY - JOUR

T1 - Systematic Roughness Variation to Model the Influence of Skewness on Wall Bounded Flows

AU - Kurth, Sebastian

AU - Cengiz, Kenan

AU - Möller, Daniel

AU - Wein, Lars

AU - Seume, Joerg R.

N1 - Funding Information: The authors would like to thank the BMWi and DFG for the support. The authors would also like to thank the North-German Supercomputing Alliance (HLRN) for the HPC resources that have contributed to the development of the research results presented here. Funding Information: Federal Ministry for Economic Affairs and Energy (BMWi) within their aviation research program (LuFo) under the funding code 20T1719C Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) within the Collaborative Research Center (CRC) 871 “Regeneration of Complex Capital Goods.

PY - 2023/6/14

Y1 - 2023/6/14

N2 - In recent years, the research on roughness has focused on various roughness features, rather than the roughness height only, in order to improve the understanding of roughness effects on wall bounded flows. A special focus is placed on the skewness of the roughness height profile. The skew-ness measures whether the height profile is dominated by negative or positive roughness elements. Surfaces with both features can be found on worn blades: On the leading edge, roughness is caused by the impact of particles resulting in a negative skewness. Rough surfaces around the trailing edge, however, develop due to depositions leading to a positive skewness. In this paper, rough surfaces taken from a compressor blade of an aero engine are systematically varied to investigate the isolated effect of skew-ness on aerodynamic losses. By direct numerical simulations of a periodic flow channel. The results show that the skewness has a major influence on loss generation. Based on these results, an existing model which essentially uses the shape-and-density parameter, is extended by a skewness factor. The modified correlation predicts the influence of the rough surfaces investigated well.

AB - In recent years, the research on roughness has focused on various roughness features, rather than the roughness height only, in order to improve the understanding of roughness effects on wall bounded flows. A special focus is placed on the skewness of the roughness height profile. The skew-ness measures whether the height profile is dominated by negative or positive roughness elements. Surfaces with both features can be found on worn blades: On the leading edge, roughness is caused by the impact of particles resulting in a negative skewness. Rough surfaces around the trailing edge, however, develop due to depositions leading to a positive skewness. In this paper, rough surfaces taken from a compressor blade of an aero engine are systematically varied to investigate the isolated effect of skew-ness on aerodynamic losses. By direct numerical simulations of a periodic flow channel. The results show that the skewness has a major influence on loss generation. Based on these results, an existing model which essentially uses the shape-and-density parameter, is extended by a skewness factor. The modified correlation predicts the influence of the rough surfaces investigated well.

KW - DNS

KW - modeling

KW - roughness

KW - skewness

KW - wall bounded flows

UR - http://www.scopus.com/inward/record.url?scp=85162931143&partnerID=8YFLogxK

U2 - 10.33737/jgpps/163089

DO - 10.33737/jgpps/163089

M3 - Article

AN - SCOPUS:85162931143

VL - 7

SP - 177

EP - 187

JO - Journal of the Global Power and Propulsion Society

JF - Journal of the Global Power and Propulsion Society

ER -