Compared to conventional Modular Pulse Converter (MPC) system with the typical structure of symmetrical T-junction, a novel swirling flow exhaust pipe system has its advantages especially in reducing collision loss of high-speed gases near junction and having interference-free scavenging and higher energy utilization. The initial junction configuration in swirling flow exhaust system was determined with reference to T-junction in MPC. In order to analyze and compare its flow behaviors, 3D-flow fields of manifold-type junctions in swirling flow exhaust pipe system were performed with the revised KIVA II code. A non-linear algebraic Relynolds stress (ASM) model was considered in this study and comparisons were made with the standard κ–ε turbulence model. For many cases of parametric studies considered, it is found that junction’s configurations have significant influence on the velocity distribution and swirl intensity. 30° swirling flow junction is found to be unreasonable, 45° junction with oblate rectangular type contraction area is recommended in swirl flow pipe exhaust pipe system.
3D-Particle Dynamic Analyzer (PDA) measurement was introduced to measure the axial and tangential velocity components of swirling flow in main pipe. Comparisons of computed and measured velocities reveal that model predictions are in generally reasonable agreement with the measurements, indicating validity of computational code and reliability of prediction model.