ABSTRACT
The Reynolds Averaged Navier-Stokes (RANS) simulation was employed to predict a turbulent flow of liquid-liquid two-phase system in standard stirred tank. The results calculated by the standard k-ε model and the Renormalization Group (RNG) k-ε model were compared to Particle Image Velocimetry (PIV) data from the literature. The constants of the transports equations were corrected, which could reflect the time-averaged strian rate of the main flow. Multi-dimensional investigation revealed the flaws of RNG k-ε model compared to standard k-ε model in predicting the liquid-liquid two-phase mixing process, which has great guidance for the selection of the turbulence models.
Nomenclature
A | = | Constant |
D | = | Impeller diameter, m |
F | = | Forces of LLP interactions |
N | = | Impeller agitation speed, rpm |
We | = | Impeller Weber number |
d32 | = | Sauter mean diameter, m |
g | = | Gravity |
k | = | Turbulence kinetic energy, m2·s−2 |
p | = | Pressure |
u | = | Velocity |
x | = | Volume fraction |
xsim | = | Simulation data |
xexp | = | Experimental data |
αd,av | = | Average dispersed phase volume fraction |
γ | = | Constant |
ε | = | Turbulence dissipation rate, m2·s−3 |
μ | = | Viscosity, kg·m−1·s−1 |
μt | = | Turbulent viscosity, kg·m−1·s−1 |
ρ | = | Density, kg·m−3 |
ρc | = | Continuous phase density, kg/m3 |
σ | = | Interfacial tension, N/m |
τ | = | Stress tensor |
LLP | = | Liquid-liquid two-phase |
rv | = | Radial velocity |
tv | = | Tangential velocity |
ST | = | Stirred tank |
sts | = | Stirred tanks |
Vin | = | Agitation speed of the rotor region |
Vs | = | Agitation speed of outside region |
Vr | = | Agitation speed of impeller |
P | = | Working pressure |
g | = | Acceleration of gravity |
T | = | Working condition temperature |
Pq | = | The relative pressure |