... inclination angle, achieving a numerical quantification of the influence of induced drag on rotor performance, as a function of both blade element longitudinal and azimuthal positions of the blade itself. Comparison between chord lengths of the blade section interacting with the flow field for the five...

... approach does not enable a correct modeling of the turbulent flow within a wheel space cavity, the authors tried to create an accurate model, taking into account the effects of inner and outer flow extraction, rotor and stator drag, leakages, injection momentum, and finally, the shroud/rim seal effects...

... outflow from a duct, such as an aircraft engine, is demonstrated to have high drag and low noise. The simplest configuration is a ram pressure-driven duct with stationary swirl vanes, a so-called swirl tube. A detailed aerodynamic design is performed using first principles based modeling and high-fidelity...

... for the flow behavior, a simple physical model to estimate the windmill speed of the rotor is developed and is found to be in good agreement with the test data. The utility of this model is that it enables the development of a procedure to predict the internal drag at engine-out conditions, which is discussed...

...J. P. Bons The effects of surface roughness on gas turbine performance are reviewed based on publications in the open literature over the past 60 years. Empirical roughness correlations routinely employed for drag and heat transfer estimates are summarized and found wanting. No single correlation...

...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...

... that have experienced degradation after service. Two different approximations are used to characterize the roughness in the computational model: the discrete element model and full 3D discretization of the surface. The discrete element method considers the total aerodynamic drag on a rough surface...

... drag and heat transfer are calculated and compared between the square and semicircle ribs, showing that two ribs produce nearly the same heat transfer, but the semicircle one yields lower drag than the square one. Contributed by the International Gas Turbine Institute (IGTI) of THE AMERICAN...

...Stephen T. McClain, Assistant Professor,; B. Keith Hodge, Professor,; Jeffrey P. Bons, Associate Professor, The discrete element method considers the total aerodynamic drag on a rough surface to be the sum of shear drag on the flat part of the surface and the form drag on the individual roughness...

... the drag crisis of a cylinder, separation-induced transition on a circular leading edge, and natural transition on a wind turbine airfoil. Turbomachinery test cases include a highly loaded compressor cascade, a low-pressure turbine blade, a transonic turbine guide vane, a 3D annular compressor cascade...

.... It is found that in general the viscous force is relatively small compared to the total blade force, even smaller the unsteady fluctuation of the viscous force and a simple drag coefficient model is quite adequate to model both time mean and dynamic viscous effects. However, for the cases when separations...