Experimental study of friction stress on the wall of a cylindrical tube in an oscillating turbulent flow of a liquid

Results of experiments where the nonstationary friction stress in an oscillating flow in a cylindrical tube was measured by a mechanical sensor within rather wide ranges of frequency (1–160Hz) and Reynolds number (1.7·10⁴–1.2·10⁵) are presented. A technique is suggested for calculating dynamic characteristics for the friction stress within three ranges of frequency, for which quasistationary and quasilaminar models of flow and a model for the intermediate frequency range are applicable. On the basis of experimental data, an approximation relation for the transmission ratio of the friction stress as a function of the dimensionless frequency is suggested. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 4, pp. 704–711, July–August, 2000.