Study on local drag reduction effects of wedge-shaped components in elbow and T-junction close-coupled pipes
elbow and T-junction close-coupled pipe, drag reduction, CFD, SST k-ω model
Close-coupled pipes are widely used in energy supply systems and the resistance in close-coupled pipes is an important factor in the energy loss and the system instabilities. In this paper, the drag reduction effect influenced by the wedge-shaped components in elbow and T-junction close-coupled pipes is investigated with the help of experimental and numerical methods. Based on physical drag reduction technologies, additional wedge-shaped components are placed in a close-coupled pipe with 32 mm inner diameter and the distance between the elbow and T-junction is 1.125 times of the inner diameter. The flow fields in the pipe are obtained by particle image velocimetry (PIV) and computational fluid dynamics (CFD). Also, the local drag reduction effects of the wedge-shaped components with different heights are discussed by adopting the SST k-ω model. The results reveal that the wedge-shaped drag reduction component with suitable height can reduce the resistance in elbow and T-junction close-coupled pipes. It is found that, in general, the largest height of wedge-shaped drag reduction components should not exceed 1/4 pipe inner diameter in HVAC field.
Tsinghua University Press
Angui Li, Xi Chen, Lei Chen et al. Study on local drag reduction effects of wedge-shaped components in elbow and T-junction close-coupled pipes. Build Simul, 2014, 7(2): 175–184.