Chen MM, Dalton C, Zhuang LX (1995) FORCE ON A CIRCULAR-CYLINDER IN AN ELLIPTIC ORBITAL FLOW AT LOW KEULEGAN-CARPENTER NUMBERS. Journal of Fluids and Structures 9(6), 617-638. [In English]

Web link: http://dx.doi.org/10.1006/jfls.1995.1034

Keywords:

viscous oscillatory flow;

Abstract: The flow structure and force acting on a horizontal circular cylinder exposed to uniform orbital flows of varying ellipticity have been determined by a finite-difference solution of the two-dimensional problem using vorticity/stream-function variables. The Keulegan-Carpenter number (KC) for the analysis is two or less with frequency parameter (beta) values of 483 and 2300. For a uniform circular orbital flow, the calculated results are compared to previous analytical and computational results with excellent agreement in most respects. For a uniform elliptical orbital flow, a series of calculations was done for three sets of parameter values, letting only the orbital ellipticity vary from circular to rectilinear. No change in the maximum total force occurred at KC = 0.1 for increasing values of ellipticity, but, for KC of 1 and 1.02, the maximum total force decreased with increasing values of ellipticity (E) at a given value of beta and E has a strong influence on the rate of decrease. The maximum total force also decreased at a given value of E as beta increased for constant KC; this decrease in force may be explained by the difference in flow patterns between the two values of beta. The formation of a small separation and reattachment region is observed for E greater than or equal to 0.8 when KC = 1.02 and beta = 2300; this how feature is evident from the spikes present in the force curve and from the surface vorticity distribution. (C) 1995 Academic Press Limited