NUMERICAL STUDY OF FULLY-DEVELOPED FLOW A RRANGEMENT IN A WAVY-WALLEDPIPE UNDER LAMINAR CONDITIONS

This study treats the influence of the wavy wall geometry on the inter nal hydrodynamics and the flow arrangement for the case of fully devel oped flow in a pipe under laminar conditions. The Navier-Stokes equati ons are established, for the case of isothermal and axisymmetric liqui d flow in a pipe characterized by a sinusoidal wall profile. The discr etization of these equations is based on a finite difference method. F or the case with vorticity and stream function as variables, the selec ted method is an algebraic transformation of the non-orthogonal coordi nates. In addition, an orthogonal mathematical field is obtained from a complex physical field. The calculation process is controlled by use of the Neumann limiting conditions and a comparison is made with the results found in the literature (flow conditions without remixing). Th e present work is also carried out to predict the best sinusoidal wall profile to obtain a large remixing effect. It is noted that the wavy wall geometry directly affects the flow arrangement: the fluid flow is fully disturbed along the radial direction for weak hydrodynamic cond itions (Re < 100), whereas for stronger conditions (Re greater-than-or -equal-to 100) this influence is only noticed near to the wavy wall. T hese results define the area of application of this wall geometry if a recirculating effect is required.