Surface Roughness Effects on External Heat Transfer of a HP Turbine Vane

Autor:	Sigmar Wittig, Matthias Stripf, Achmed Schulz
Rok vydání:	2005
Předmět:	Materials science Meteorology Turbulence Mechanical Engineering Reynolds number Mechanics Surface finish Heat transfer coefficient Physics::Fluid Dynamics Boundary layer symbols.namesake Roughness length Heat transfer Surface roughness symbols
Zdroj:	Journal of Turbomachinery. 127:200-208
ISSN:	1528-8900 0889-504X
Popis:	External heat transfer measurements on a highly loaded turbine vane with varying surface roughness are presented. The investigation comprises nine different roughness configurations and a smooth reference surface. The rough surfaces consist of evenly spaced truncated cones with varying height, diameter and distance, thus covering the full range of roughness Reynolds numbers in the transitionally and fully rough regimes. Measurements for each type of roughness are conducted at several freestream turbulence levels (Tul = 4% to 8.8%) and Reynolds numbers, hereby quantifying their combined effect on heat transfer and laminar-turbulent transition. In complementary studies a trip wire is used on the suction side in order to fix the transition location close to the stagnation point, thereby allowing a deeper insight into the effect of roughness on the turbulent boundary layer. The results presented show a strong influence of roughness on the onset of transition even for the smallest roughness Reynolds numbers. Heat transfer coefficients in the turbulent boundary layer are increased by up to 50% when compared to the smooth reference surface.Copyright © 2004 by ASME
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::dcd0260dff4b4932ac3a41dea0dc6aa2 https://doi.org/10.1115/1.1811101 Zobrazit plný text záznamu