ID 328

Estimating turbulent kinetic energy and dissipation with internal flow loss coefficients

 

Abstract:

Estimating the turbulent kinetic energy at the nozzle outlet is necessary to model turbulent jet breakup. We identified errors in a model of nozzle turbulence developed by Huh et al. which made the model inaccurate. To develop an improved model, we derived a generalized form of the Bernoulli equation for non-cavitating flows. The equation can be used to estimate turbulent kinetic energy, k, and dissipation, ε, in internal flows given loss coefficients or friction factors and a turbulence model. The equation allows turbulent kinetic energy and dissipation to be estimated without computational fluid dynamics. The estimates can be used as-is where turbulent kinetic energy or dissipation are desired, or as a more accurate boundary condition for computational fluid dynamics. A model for fully developed pipe flow is developed and compared against experimental data. A nozzle turbulence model which could replace Huh et al.'s is also developed, but the model has not been validated due to a lack of experimental data.