Translational Flow Past a Cylinder

In chemical technology and power engineering, equipment containing heat exchanging pipes and various cylindrical links immersed into moving fluid is often used. The estimation of the hydrodynamic action on these elements is based on the solution of the plane problem on the flow past a cylinder. 

Low Reynolds numbers. In [216, 382] the problem on a circular cylinder of radius a in translational flow of viscous incompressible fluid with velocity Ul at low Reynolds numbers was solved by the method of matched asymptotic expansions. The study was carried out on the basis of the Navier-Stokes equations (1.1.4) in the polar coordinates 1Z, 6. Thus, the following expression for the stream function was obtained for IZ/a 1  

By using the stream function (2.7.1), one can calculate the drag coefficient 

Comparison with experimental data shows that formula (2.7.2) can be used for 0 Re 0.4 [485]. 

Nonseparating flow past a cylinder at moderate Reynolds numbers. According to experimental data [486], a nonseparating flow past a circular cylinder is realized at Re 2.5. At such Reynolds numbers, one can use the following approximate formula for calculating the drag coefficient [94]  

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