Concerning the features of deformation of a compliant coating by pressure pulsations in a turbulent boundary layer
V.M. Kulik
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: турбулентное течение, вязкоупругие свойства, динамическая податливость, граничные условия, стационарный режим, время установления вынужденных колебаний, turbulent flow, viscoelastic properties, dynamic compliance, boundary conditions, stationary regime, time of stabilization of forced oscillations
Abstract
Deformations of a compliant coating in a turbulent flow, measured previously and calculated in this work, are compared. The calculated spectral density of coating deformations at low frequencies (25-250 Hz) turned out to be almost two orders of magnitude higher than the measured one, and the rms value of the measured deformation was seven times lower than the calculated one. The transitional regime for stabilizing the forced coating oscillations under the action of a pressure wave is calculated. It is shown that the coating almost always works in the transition regime, without reaching the maximum deformation amplitudes that are characteristic of the steady state. It is concluded that it is necessary to use more complex boundary conditions that take into account the non-stationary character of the process because the amplitude of coating deformation varies in a complex way during the lifetime of organized structures moving in a turbulent boundary layer.
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