...Stephen T. McClain; B. Keith Hodge; Jeffrey P. Bons The discrete-element model for flows over rough surfaces considers the heat transferred from a rough surface to be the sum of the heat convected from the flat surface and the heat convected from the individual roughness elements to the fluid...

...Stephen T. McClain; Jason M. Brown The discrete-element model for flows over rough surfaces was recently modified to predict drag and heat transfer for flow over randomly rough surfaces. However, the current form of the discrete-element model requires a blockage fraction and a roughness-element...

...Hugh M. McIlroy, Jr.; Ralph S. Budwig Results are presented of extensive boundary layer measurements taken over a flat, smooth plate model of the front one-third of a turbine blade and over the model with an embedded strip of realistic rough surface. The turbine blade model also included elevated...

... roughness on heat transfer and pressure loss is determined along with the various interactions among these parameters. 12 12 2003 31 08 2004 heat transfer jets rough surfaces boundary layers infrared imaging temperature measurement First presented at the 2001 International...

... transfer rough surfaces turbulence external flows Introduction of roughness by ribs in flow passages is a popular method of enhancing heat transfer in the cooling passages, e.g., of turbine blades and combustors. The heat transfer and fluid flow in ribbed ducts have been extensively studied both...

... roughness but overpredict St for real roughness. These findings expose limitations in the traditional equivalent sandgrain roughness model and the common use of ordered arrays of roughness elements to simulate real roughness surfaces. The elevated freestream turbulence levels produce augmentation ratios...

... turbines cooling film flow rough surfaces coatings heat transfer friction Roughness Spallation Turbine Modern land-based turbine airfoils operate in severe environments with high temperatures and near critical stresses. Highly turbulent combustor exit flows, with significant thermal...

... cooling jets heat transfer rough surfaces Various methods have been developed over the years to keep the airfoil temperatures below critical levels. A main objective in turbine blade cooling design is to achieve maximum heat transfer coefficients while minimizing the coolant flow rate. One...

..., but is not evident in the figures, is an indication of a lower than expected recovery factor for a rough surface. It was observed that measurements with lower wall-to-gas temperature differences gave higher heat transfer rates. The recovery temperatures were calculated using a recovery factor of 0.89. A lower...

... Turbine and Aeroengine Congress and Exhibition, Munich, Germany, May 8–11, 2000. Manuscript received by the International Gas Turbine Institute February 2000. Paper No. 2000-GT-230. Review Chair: D. Ballal. 08 May 2000 01 February 2000 gas turbines heat transfer rough surfaces...

.... Manuscript received by the International Gas Turbine Institute February 2000. Paper No. 2000-GT-222. Review Chair: D. Ballal. 08 May 2000 01 February 2000 gas turbines cooling heat transfer convection rough surfaces jets flow measurement Figures 1 and 2 show...

... boundary layer turbulence aerodynamics cascade systems rough surfaces flow control gas turbines The aerodynamic performance of turbomachinery blading is strongly dependent on the nature of boundary layer development on the blades. The blade boundary layer is responsible for the airfoil...

... rotational flow rough surfaces boundary layers shear flow flow separation pressure control Centrifugal Blower Vaneless Diffuser Rotating Stall Three-Dimensional Boundary Layer Separation Control Rough Wall Suppression of unstable flow, such as rotating stall and surge, is one...

.... The wavelet analysis suggested that transition over rough surfaces may be in bypass mode because the disturbances were shown to be amplified in a broad spectral band. [S0889-504X(00)00302-0] Contributed by the International Gas Turbine Institute and presented at the 44th International Gas Turbine...

... Layer Development along a Turbine Blade With Rough Surfaces ,” ASME J. Eng. Power , 102 , pp. 978 – 983 . Boynton , J. L. , Tabibzadeh , R. , and Hudson , S. , 1993 , “ Investigation of Rotor Blade Roughness Effects on Turbine Performance ,” ASME J. Turbomach. , 115 , pp. 614...

...–10, 1999. Manuscript received by the International Gas Turbine Institute February 1999. Paper No. 99-GT-254. Review Chair: D. C. Wisler. 07 June 1999 01 February 1999 convection heat transfer computational fluid dynamics turbulence rough surfaces gas turbines...