Drag reduction in a rectangular duct using riblets

Autor:	AR Moore, MV Lowson
Rok vydání:	1995
Předmět:	Drag coefficient Materials science Turbulence Aerospace Engineering Reynolds number Mechanics External flow Fully developed symbols.namesake Parasitic drag Drag symbols Duct (flow) Simulation
Zdroj:	The Aeronautical Journal. 99:187-193
ISSN:	2059-6464 0001-9240
DOI:	10.1017/s0001924000028360
Popis:	An experimental investigation has been made into the effects of riblets on the drag in a rectangular duct of aspect ratio 10. It has been found that a maximum drag reduction of approximately 10% occurs in fully developed turbulent flow. This figure is larger than the 6–8% drag reduction usually found for external flow. The maximum drag reduction occurred when the height of the riblets was between 7 and 13 wall units. Analysis of the developing region of the flow has shown a maximum drag reduction of approximately 8% at a wall unit value of 13, consistent with results in external flows. The effects of riblets on transition has also been investigated. It was found that riblets delayed transition by 2–4% in critical Re as measured by peak flatness, and caused some extension in the length of the transition process, so that the completion of transition was delayed by between 4–8%, with the stronger effect at the lower Reynolds numbers.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c1c2835bfc25989598626d38441f313a https://doi.org/10.1017/s0001924000028360 Zobrazit plný text záznamu