Abstract Transient flow characteristics and dissipation mechanism in pressurized pipeline were investigated based on 1D friction models 3D turbulence models, where the pressure–density model was combined into continuity equation allowing for elasticity of fluid pipes. The applicability realizable k–ε SST (shear stress transport) k–ω verified with comparison to traditional water hammer experimen...

This paper presents a way of modelling turbulence in multiphase flows within the context of the Reynolds-Stress Model. The model has been implemented in the general-purpose unstructured finite volume code Fluent V6. Two multiphase turbulence approaches were considered: mixture and dispersed models. The mixture model solves the Reynolds-stress transport equations on the mixture level only. The d...

Wind energy is one of the clean renewable energy. However, the low frequency (20-200HZ) noise generated from the wind turbine blades, which bothers the residents, becomes the major problem to be developed. It is useful for predicting the aerodynamic noise by flow field and pressure distribution analysis on the wind turbine blades. Therefore, the main objective of this study is to use different ...

Turbulence parameters in the tropo-stratosphere are analyzed using high-resolution balloon temperature measurements collected during the MUTSI (MU radar, Temperature sheets and Interferometry) campaign which took place near the Middle and Upper atmosphere (MU) radar (Japan, 35 N, 136 E) in May 2000. Vertical profiles of the specific dissipation rate of turbulent kinetic energy, ε, and turbulent...

Diverse arrays of modern applications require accurate predictions of complex turbulent flows. These range from flows across aircraft and inside turbomachinery, over the planet for weather prediction and through the heart for cardiac auscultation, etc. Due to the disparate character of these complex flows, predictive methods must be robust so as to be applicable for most of these cases, yet pos...

A quad inserted into a turbulent boundary layer of a flat plate and its effect on average heat transfer and the friction coefficient is studied. To optimize this effect, the edge sizes and distance of the quad from the flat plate are continually modified. In each case, simultaneously the heat transfer enhancement and reduction in skin friction are analyzed. For optimization, the genetic algorit...

Two combustion models for turbulent premixed combustion in the flamelet regime are developed for unsteady simulations. The first model is a convensional G equation flamelet model and the main issues discussed are the subgrid closure. The second model is based on the Linear-Eddy Model. Both models are used in simulation of turbulent stagnation point flames. The heat release and turbulence intens...

Turbulence plays an important role in many chemical engineering processes (fluid flow, mass and heat transfer, chemical reactions) which are dominated by convective transport. Since the direct numerical simulation (DNS) of turbulent flows is still prohibitively expensive, eddy viscosity models based on the Reynolds Averaged Navier-Stokes (RANS) equations are commonly employed in CFD codes. One ...