Boundary conditions on a compliant wall in the turbulent flow
V.M. Kulik
Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: compliant coating, turbulent flow, boundary conditions, optimal parameters, value of deformation, velocity pulsations
Abstract
It is shown that with an increase in elasticity modulus of the coating material from 0.01 MPa to 100 MPa the pulsation velocity of coating surface changes not more than by 30 % and equals 0.17–0.24 of the value of dynamic flow velocity, and this can change significantly Reynolds stresses in the near-wall area. According to performed analysis, it was found out that the deformation value of the compliant coatings within the velocity range, optimal for their interaction with the turbulent flow, is only several units of the viscous scale. Moreover, these deformations are very gentle: the ratio of amplitude of deformation to wavelength is less than 10–3. It is assumed that while modeling the interaction between the compliant coating and turbulent flow it is not necessary to transfer the boundary conditions to the moving coating surface. Perhaps, it will be sufficient to determine the velocity of wall motion over the undisturbed coating surface.
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