Design and Numerical Investigation to Predict the Flow Pattern of Non-axisymmetric Convergent Nozzle:A Component of Turboexpander

• 作者: Debashis Panda Manoj Kumar Ranjit Kumar Sahoo Rasmikanti Biswal Suraj Kumar Behera
• 来源期刊: 交通与运输工程:英文版
• 学科: 物理学
• 关键词: FLUID flow PATTERN NON-AXISYMMETRIC NOZZLE air CFD turboexpander
• 年，卷（期）: 2019,（6）
• 页码范围: 264-281
• 页数: 18页
• 分类号: O35

摘要

Current work proposes a novel design methodology using curve-fitting approach for a non-axisymmetric airfoil convergent nozzle used in small-sized cryogenic turboexpander.The curves used for designing the nozzle are based on a combination of fifth and third order curve at upper and lower surface respectively.Four different turbulence model such as k-ε,SST,BSL and SSG Reynolds stress turbulence model is used to visualize and compare the fluid flow characteristics and thermal behaviors at various cross-sections.It is interesting to observe that the Mach number obtained at the outlet of the nozzle is highest and temperature drop is maximum for SSG model under similar boundary conditions.It is also observed that the designed nozzle with curve fitting approach is appropriate for impulse type turbine with a small amount of reaction.The key feature of this implementation is to obtain subsonic velocity at the nozzle exit and reduce the irreversible losses through the nozzle,which can affect the performance of a turboexpander.