Investigation of 2D Invisid Condensation Flow in Convergent Divergent Nozzle with Heating Source Term in Convergent Section

Wetness loss is a thermodynamic loss، which is due to irreversible heat transfer between the liquid and vapour phase during condensation. Formation and subsequent behavior of the liquid decreases the performance of turbine last stages. This phenomenon has a major effect on the efficiency of steam turbines. In this study، the steady compressible condensation flow field with heat transfer in a two dimensional of convergent divergent nozzle has been studied. The ANSYS FLUENT V14. 5 software is used to calculate flow properties. The CFD coded 2D- approximate Eulerian- Eulerian multi- phase method for non- equilibrium condensation in transonic steam flow is used to capture nucleation phenomenon in the wet steam flow. Density based finite- volume discritization is employed and flow is considered inviscid. To examine heat transfer effects on the condensation flow in the convergent section of nozzle، a thermal source is used. The perfect gas equation of state is used to calculate the pressure and the properties of steam condensation. The pressure distribution over the nozzle and the average radius of droplets in adiabatic case are compared with both experimental and analytical data and show a good agreement. After verifying the model، the condensation flow with volumetric heat transfer is studied. The results show that by adding volumetric heating in convergent section of the nozzle the condensation shock strength decreases and even is omitted which cause to reduce droplets produced during the condensation flow.