Study on reduction in pressure losses in pipe bends using guide vanes

Abstract

The pipe bends are common elements in pipeline network of mechanical systems. The losses in pipes and bend are generally considered as insignificant and unavoidable. The recent trends in achieving a higher order of performance in machines led to optimization by reduction in minor energy losses. The usage of components with the higher surface finish is the main methodology adopted for minimizing frictional loss. In bends, especially in the case of turbulent flows, the losses are significant when comparing the frictional pipe losses. The viscous interaction between fluid layers is more in bends due to the presence of flow separation secondary swirling motion. The reduction in these interactions can be achieved by installing turning vane (guide vanes) inside the pipe bend. The current literature available lacks detailing of many included flow physics in bends and vaned bends. The present work focuses on flow characteristics on a 90° curved bend. Incompressible isothermal RANS solutions were performed using turbulence treatment with the k − ω SST model. The initial validation study is carried out with available experimental results. The bend downstream velocity distribution and bend wall pressure distribution are carried out. Further, the computational methodology is extended to bend with different vane configurations and for different Reynolds numbers. The velocity, wall pressure, swirl strength, turbulent kinetic energy, etc. are reported for downstream locations. The comparison of pressure loss through different cases and improvements in flow through bend due to the inclusion of vanes are discussed in this work.