Experimental study of the flow across an elliptic cylinder at subcritical Reynolds number
Department of Mechanical Engineering, Hakim Sabzevari University, Sabzevar, Iran
* e-mail: M.J.EzadiYazdi@semnan.ac.ir
Accepted: 15 October 2018
Published online: 20 December 2018
In this work, an incompressible flow across an elliptic cylinder with an axial ratio of 0.5 was experimentally studied in a low-turbulence horizontal wind tunnel at two Reynolds numbers: and . Hot-wire anemometry measurements were carried out in the cylinder wake to obtain turbulence intensity, average stream-wise velocity, higher-order central moments of velocity signals (i.e. skewness and flatness), and dimensionless vortex shedding frequency for the two Reynolds numbers. The obtained results showed that, the turbulence intensity profiles in the wake become broader as one moves toward downstream and peak turbulence intensities occur at points of high velocity gradient along the velocity profile. With increasing the Reynolds number, lower turbulence intensity and velocity defect parameters were observed within the near-wake zone. It was further observed that, upon the increase in Reynolds number at constant axial ratio, the wake became narrower with its Strouhal number (associated with the Kármán vortex) remaining constant. In addition, the drag coefficient decreased with increasing the Reynolds number. When it came to the drag coefficient, the results of the present research were in good agreement with other experimental works.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2018