汽车废热发电系统中喷管的流速场数值模拟

Numerical Simulation of Flow Velocity Fluid in Nozzle in the Automobile Waste Heat Generation System

采用有限元法通过控制容积方程对三种渐缩型喷管(锥型喷管、整流型喷管、变截面型喷管)中流体流动进行数值模拟.计算结果表明:在相同工况下,当λ=b/a=0.16时,锥型喷管出口流速最大,回流最小.计算结果表明,对废热发电系统中汽轮机喷管,特别是有机工质低沸点朗肯双循环系统所用的汽轮机喷管的设计有参考价值.

The finite element method is adopted to numerically simulate the flow velocity fluid in three kinds of nozzles （cone- shaped nozzle, rectified nozzle, variational section nozzle） through the control volume equation. The results indicate that velocity in the outlet is the biggest and backflow is the smallest in conical jet nozzle under the same operating condition, when λ = b/α = 0. 16. The computed results will have reference value for the waste heat generation system nozzle, especially for the steam turbine nozzle used in Rankine double circulation system with the organic working substance low boiling point.