CENTRIFUGAL STAGE PERFORMANCE PREDICTION AND VALIDATION FOR HIGH MACH NUMBER APPLICATIONS
Steve Kowalski is an Aero-Thermo Engineer in the Research and Development Department of DresserRand. His responsibilities include the design, development and analysis of aerodynamic components of centrifugal compressors. He has been employed at Dresser-Rand since 2007. He holds a B.S. degree from Michigan State University (Mechanical Engineering, 2002) and an M.S. degree from Michigan State University (Mechanical Engineering, 2005). Prior to joining Dresser-Rand, he worked as a teaching/research assistant at Michigan State University.
遠心圧縮機の旋回失速に関する研究 : 第2報, 羽根なしディフューザ入口形状の影響
Rotating stall induced in a vaneless diffuser is examined. Combination of several low specific speed impellers and three types of diffusers with different inlet shape are tested. In the lower specific speed stages, the critical inlet flow angle for rotating stall depends not only on diffuser width ratio b/r2, and contraction ratio b/b2, but also on the inlet shape of the diffuser. As the inlet shape parameter Δr/r2 becomes smaller than value of 0.1, the critical inlet flow angle becomes larger than the predicted value by the Senoo method. The empirical prediction formula of critical inlet flow angle in the first report is corrected by considering the influence of inlet shape. Influence of inlet shape on rotating stall phenomenon is also shown.
CFD simulation of hydrodynamics and heat transfer in gas phase ethylene polymerization reactors
Abstract The hydrodynamics and temperature of a two-dimensional gas–solid fluidized bed of gas phase olefin polymerization reactor had been studied. A two-fluid Eularian Computational Fluid Dynamics (CFD) model with closure relationships according to the kinetic theory of granular flow has been applied in order to simulate the gas–solid flow. Fluidization regime and gas–solid flow pattern were investigated using three different drag models. Model predictions of bed pressure drop were compared with corresponding experimental data reported in the literature to validate the model. The predicted values were in reasonable agreement with the experimental data. The temperature behavior of fluidized bed with various drag models was investigated. The temperature gradient in the primary section of the bed was much larger than the gradient in other sections and the effect of all drag models on temperature gradient along the bed was approximately similar.