A numerical investigation of developing flow and heat transfer in a curved pipe

Abstract

PurposeThis article aims to study numerically three dimensional developing incompressible flow and heat transfer in a fixed curved pipe.Design/methodology/approachA projection algorithm based on the second order finite difference method is used for discretizing governing equations written in the toroidal coordinate system.FindingsThe effects of curvature and governing non‐dimensional parameters consisting of Reynolds, Prandtl, and Dean numbers on the flow field, entrance length, and heat transfer are studied in detail. The numerical results indicate that the entrance length depends only on the Reynolds number for the curvature ratios greater than 1/7 and therefore, Dean number is not a pertinent parameter in this range.Research limitations/implicationsFor heat transfer analysis, two different thermal boundary conditions, i.e. constant wall temperature and constant heat flux at the wall are implemented. The results are calculated for the Dean numbers in the range of 76‐522 and for the two prandtl numbers of 0.5 and 1.Practical implicationsThe results can be used in designing heat exchangers, piping systems, and cooling of gas turbine blades.Originality/valueThe numerical results obtained here concentrate on the detailed investigation of flow and temperature field at the entrance region by a quantitative analysis of hydrodynamic and thermal entrance length. The effects of different thermal boundary conditions and different inlet profiles on the flow and temperature fields are studied in the circular curved pipe for the first time.