Most indoor airflows are mixed convection. In order to simulate mixed convection accurately and efficiently, this paper uses a two-layer turbulence model. The two-layer model combines a one-equation model for near wall flow together with the standard k-epsilon model for outer-wall flow. The model has been used to predict the mixed convection by displacement ventilation in an office. The compute...

In this study, modeling of a fuel jet which has been injected by high pressure into a low-pressure tank are investigated. Due to the initial conditions and the geometry of this case and similar cases (like CNG injectors in internal combustion engines (ICE)), the barrel shocks and Mach disk are observed. Hence a turbulence and transient flow will be expected with lots of shocks and waves. Accord...

Flow separation at water intake is the main cause of head loss and flow discharge reduction. &#10As a result, study of shape and size of separation is very essential when designing an optimum water intake. Water intake is normally built with a 90 degree angle to the main channel flow direction. However, the flow structure in this type of water intake consists of large separation size along wit...

The Yakhot and Orszag RNG theory of turbulence has generated a number of scaling law constants in reasonable quantitative agreement with experiments. The theory itself is highly mathematical, and its assumptions and approximations are not easily appreciated, particularly since several rather unconventional artifices are employed. The present paper reviews the RNG theory and recasts it in more c...

Flow separation at water intake is the main cause of head loss and flow discharge reduction. As a result, study of shape and size of separation is very essential when designing an optimum water intake. Water intake is normally built with a 90 degree angle to the main channel flow direction. However, the flow structure in this type of water intake consists of large separation size along with ...

With the increase of computer power and advancement of modeling software, the study of turbulent gas-particle flow problems using computational fluid dynamics (CFD) techniques is gradually becoming attractive in the engineering field. Two basic CFD approaches are used to simulate the gas-particle flow, i.e. the Eulerian-Lagrangian model and the EulerianEulerian model. The aim of this thesis is ...

1. Objective The objective is to understand and extend a recent theory of turbulence based on dynamic renormalization group (RNG) techniques. The application of RNG methods to hydrodynamic turbulence has been explored most extensively by Yakhot and Orszag (1986). They calculate an eddy viscosity consistent with the Kolmogorov inertial range by systematic elimination of the small scales in the f...