Pressure Gradient Effects on the Performance of Riblets Installed on Aircraft Surfaces
- 1 March 2022
- journal article
- research article
- Published by American Institute of Aeronautics and Astronautics (AIAA) in Journal of Aircraft
- Vol. 59 (2), 447-457
- https://doi.org/10.2514/1.c036409
Abstract
A method for estimating the drag reduction performance of riblets installed on the surfaces of an aircraft was extended to take the effect of the pressure gradient over the aircraft into account. This method simply and roughly estimates the effectiveness of riblets applied to arbitrary surfaces of any aircraft by fusing wind tunnel test data and computational fluid dynamics analysis. The drag reduction rate is calculated from the relationships between friction drag reduction , wall-normalized riblet spacing , and Clauser pressure gradient parameter . To obtain this relationship, a wind tunnel test with straight riblets in an adverse pressure gradient was carried out. The resulting shift in the value in the intercept of the log-law region of the mean velocity profile for riblet cases indicates that the drag reduction effect decreases as the Clauser parameter increases. Based on these results, an approximate surface for the relationship between , , and was proposed, and the drag reduction performance of riblets installed on the surfaces of a conceptual aircraft was estimated. The total drag reduction rates estimated by the extended method considering pressure gradient effects and the original method case were both about 2%, which indicates that the effects of the pressure gradient on the aircraft on overall riblet performance are small.
Keywords
This publication has 30 references indexed in Scilit:
- Structure of turbulent boundary layer subjected to adverse pressure gradientInternational Journal of Heat and Fluid Flow, 1998
- Experiments on drag-reducing surfaces and their optimization with an adjustable geometryJournal of Fluid Mechanics, 1997
- Turbulent boundary layer in an adverse pressure gradient - Effectiveness of ribletsAIAA Journal, 1996
- Regeneration mechanisms of near-wall turbulence structuresJournal of Fluid Mechanics, 1995
- Turbulent drag reduction mechanism above a riblet surfaceAIAA Journal, 1994
- Direct numerical simulation of turbulent flow over ribletsJournal of Fluid Mechanics, 1993
- Resistance of a grooved surface to parallel flow and cross-flowJournal of Fluid Mechanics Digital Archive, 1991
- Effects of Longitudinal Pressure Gradients on Turbulent Drag Reduction with RibletsPublished by Springer Science and Business Media LLC ,1990
- Riblets as a Viscous Drag Reduction TechniqueAIAA Journal, 1983
- An evaluation of theories for predicting turbulent skin friction andheat transfer on flat plates at supersonic and hypersonic Mach numbersAIAA Journal, 1971