...Weichen Huang; Kechen Wang; Fei Zeng; Wenbin Chen; Wenwu Zhou; Xin Wen; Di Peng; Yingzheng Liu Roughness caused by deposition, erosion, and additive manufacturing can significantly affect gas turbine efficiency. Previous research has often examined film cooling performance under limited roughness...

... the current coupons and datasets from the literature. Arithmetic mean roughness correlations in the literature struggled to predict the cooling performance of AM channels since the bulk roughness statistic did not capture the overall form of the surface morphology. A combination of root mean square roughness...

... such as freestream turbulence, upstream wakes, and surface roughness. These mechanisms have proven to be beneficial in mitigating the separation bubble-related losses in ultra-high-lift blade designs, despite an increase in the loss due to increased turbulent wetted area (TWA). In this work, we adopt a strategy...

..., due to typical roughness induced by AM, current wall models used in steady and unsteady 3D Navier–Stokes simulations do not take into account such characteristics. For the development and assessment of novel wall models for AM, a high-fidelity roughness-resolved large-eddy simulation (RRLES) database...

...Alexander J. Wildgoose; Karen A. Thole; Ramesh Subramanian; Lisa Kersting; Anand Kulkarni By leveraging the additive manufacturing (AM) platform, development time and costs for turbine component testing can be reduced relative to traditional investment casting. Surface roughness is a key...

...Lorenzo Mazzei; Riccardo Da Soghe; Cosimo Bianchini It is well known from the literature that surface roughness significantly affects friction and heat transfer. This is even more evident for additive manufactured (AM) components, which are taking an increasingly important role in the gas turbine...

...Steven R. Mart, Graduate Student; Stephen T. McClain, Assistant Professor; Lesley M. Wright, Assistant Professor Many flows of engineering interest are bounded by surfaces that exhibit roughness with thermal conductivities much lower than common metals and alloys. Depending on the local roughness...

... the roughness peaks and allowed the coolant to stay attached to the model. Increasing the blowing ratio from 0.5 to 2 only expanded the region that the coolant could reach and improved the cooling effectiveness. Though the heat transfer coefficient also increased at high blowing ratios, the net heat flux ratio...

... 1 year of operation). Three-dimensional maps of the deposit-roughened surfaces were created between each test, representing a total of four measurements evenly spaced through the lifecycle of a turbine blade surface. From these measurements the surface topology and roughness statistics were...

... roughness turbines Though the skin friction coefficient was not measured for the roughness models, an empirical correlation proposed by Schlichting was used to estimate its value ( 17 ) 4 c f = [ 2.87 + 1.58 log ( L ∕ k s ) ] − 2.5 This was combined...

...Jeffrey P. Bons Experimental measurements of skin friction c f and heat transfer (St) augmentation are reported for low speed flow over turbine roughness models. The models were scaled from surface measurements taken on actual, in-service land-based turbine hardware. Model scaling factors ranged...

...Jeffrey P. Bons; Robert P. Taylor; Stephen T. McClain; Richard B. Rivir Results are presented for contact stylus measurements of surface roughness on in-service turbine blades and vanes. Nearly 100 turbine components were assembled from four land-based turbine manufacturers. Both coated...