The attachments only provided the set-up for the simulation. They are as follows:
Flow Physics
Solver: Transient and gravity (-9.81m/s2) turned on
Operating condition: 2MPa, 303 deg C, 0kg/m3
Turbulence model: k-omega SST, turbulence damping =10
Multiphase model: Eulerian-Multi-Fluid VOF, Explicit formulation, sharp interface, interfacial diffusion turned on, 0.25 Courant, 1e-06 volume fraction cutoff, 2 phase (ideal gas and water as materials), Cp-piecewise-polynomial. Drag coefficient - anisotropic-drag, surface tension turned on, surface tension coefficient -1.406, interfacial area - ia-symmetric
Boundary condition: For Inlet-gas: turbulent intensity-5%, hydraulic diameter-0.21m, mass flow rate-7.620921kg/s, mass-flow inlet
For Inlet-liquid: turbulent intensity-5%, hydraulic diameter-0.21m, mass flow rate: 276.6256kg/s, volume fraction-1, mass-flow inlet
For outlet: Pressure-outlet, turbulent intensity-5%, hydraulic diameter-0.21m, backflow volume fraction-0
For wall: stationary wall, no-slip condition
Solution methods:
Solution control: pressure-3, density-1, body forces-1, momentum-0.7, TKE-0.8, SDR-0.8, TV-1, Energy-0.5
Residuals
Initialization:
Firstly, the solution was initialize with the liquid in the domain. A time-step size of 1e-04 to 1e-06 was used to reduce the global courant number further down but the simulation stopped with the error below.
There are also messages like turbulent viscosity larger than 1.000000.
However, when i initialized the solution with the gas, the solution converged even in reverse flow condition. Anyway i am not comfortable with initializing the solution from the inlet-gas. I also changed the turbulence multi-phase model to "per phase". Also, the interfacial modelling was changed to sharp/dispersed and the volume fraction formulation to implicit. Lastly, for this case, all the spatial discretization was changed to QUICK. These changes were done when the solution was initialized with gas. However, I want to initialize from the inlet-liquid. In this case the liquid fills the domain at first while gas goes through the center
Flow Physics
Solver: Transient and gravity (-9.81m/s2) turned on
Operating condition: 2MPa, 303 deg C, 0kg/m3
Turbulence model: k-omega SST, turbulence damping =10
Multiphase model: Eulerian-Multi-Fluid VOF, Explicit formulation, sharp interface, interfacial diffusion turned on, 0.25 Courant, 1e-06 volume fraction cutoff, 2 phase (ideal gas and water as materials), Cp-piecewise-polynomial. Drag coefficient - anisotropic-drag, surface tension turned on, surface tension coefficient -1.406, interfacial area - ia-symmetric
Boundary condition: For Inlet-gas: turbulent intensity-5%, hydraulic diameter-0.21m, mass flow rate-7.620921kg/s, mass-flow inlet
For Inlet-liquid: turbulent intensity-5%, hydraulic diameter-0.21m, mass flow rate: 276.6256kg/s, volume fraction-1, mass-flow inlet
For outlet: Pressure-outlet, turbulent intensity-5%, hydraulic diameter-0.21m, backflow volume fraction-0
For wall: stationary wall, no-slip condition
Solution methods:
Solution control: pressure-3, density-1, body forces-1, momentum-0.7, TKE-0.8, SDR-0.8, TV-1, Energy-0.5
Residuals
Initialization: Firstly, the solution was initialize with the liquid in the domain. A time-step size of 1e-04 to 1e-06 was used to reduce the global courant number further down but the simulation stopped with the error below.
There are also messages like turbulent viscosity larger than 1.000000.However, when i initialized the solution with the gas, the solution converged even in reverse flow condition. Anyway i am not comfortable with initializing the solution from the inlet-gas. I also changed the turbulence multi-phase model to "per phase". Also, the interfacial modelling was changed to sharp/dispersed and the volume fraction formulation to implicit. Lastly, for this case, all the spatial discretization was changed to QUICK. These changes were done when the solution was initialized with gas. However, I want to initialize from the inlet-liquid. In this case the liquid fills the domain at first while gas goes through the center
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