Numerical Analysis Of Flow Field In Turbine And Safety Valve By CFD

Computational Fluid Dynamics (known as CFD for short) is generally adopted in engineering practice, which has greatly stimulated academic research. The flow field in turbine has been simulated in this dissertation by using FLUENT, and a transient simulation of two-phase flow in safety valve also has been completed with CFX. The principal research work is listed as follows:(1) In the simulation of turbine, the impacts of wake on interior flow field between blades are investigated in detail, where the relevant velocity fields and pressure fields have been presented.(2) The effect of installation angle of the blades and inlet conditions on interior flow field has been analyzed separately. The efficiency of turbine is decreased with the reduction of Reynolds number, and the causes of efficiency loss have also been discussed in this dissertation.(3) The suitability of the two-phase models and cavitation models is discussed; a transient simulation of two-phase flow in safety valve with an inlet vessel has been completed, and many important phenomena of the flow in the safety valve are analyzed by using the obtained results.(4) Comparison on the interior flow field with and without cavitation show that the simulation with cavitation is more suitable for fact, and the cavitation also has been analyzed.