DRAG COEFFICIENTS UNDER TURBULENT FLOW OF A VISCOUS FLUID IN THE ANNULAR GAP OF TWO COAXIAL CYLINDRICAL TUBES

The problem of the theoretical description of the dynamics of turbulent fluid flow in two coaxial cylindrical pipelines is considered with the purpose of determining the dependence of the resistance to movement on its viscosity and the ratio of their magnitudes. The dependences of the drag coefficients on the Reynolds number are theoretically investigated for various roughnesses of the pipe surface and various ratios of their diameters.