Investigation of the effects of reynolds number on the unsteady flow physics of airfoil dynamic stall

Rohit Gupta, Phillip J. Ansell

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A series of wind-tunnel experiments were conducted on a dynamically pitching airfoil at Rec = 0.5 × 106 and 1 × 106 in order to understand the effects of Reynolds number on the unsteady flow physics associated with dynamic stall. An NACA 0012 airfoil was dynamically pitched about the quarter-chord axis following a linear ramp maneuver at ω+ = 0.05. A series of high-frequency unsteady surface pressure measurements were acquired in order to investigate the time-dependent behavior of the flow in the immediate vicinity of the airfoil at two transition Reynolds numbers. These surface pressure measurements actively displayed the evolution of the airfoil boundary layer, leading-edge laminar separation bubble, and the dynamic stall vortex at the corresponding Rec. Detailed time-frequency analysis of surface pressure measurements was performed in order to identify the dominant frequencies associated with the unsteady laminar separation bubble. This analysis was also used to study the evolution of the length scales associated with flow structures near the airfoil leading edge, which emerged prior to the formation of the dynamic stall vortex. Finally, TR-PIV measurements were acquired to compare the evolution of the off-body flow field, with particular emphasis on understanding the development of the dynamic stall vortex at Rec = 0.5 × 106 and 1 × 106.

Original languageEnglish (US)
Title of host publicationAIAA Aerospace Sciences Meeting
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624105241
StatePublished - 2018
Externally publishedYes
EventAIAA Aerospace Sciences Meeting, 2018 - Kissimmee, United States
Duration: Jan 8 2018Jan 12 2018

Publication series

NameAIAA Aerospace Sciences Meeting, 2018


OtherAIAA Aerospace Sciences Meeting, 2018
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Aerospace Engineering


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