at the present work, the effect of cold exhaust gas recirculation (egr) on combustion and pollution of a dual fuel engine has been investigated by cfd code fire. the turbulent flow within the combustion chamber is simulated using the k-ε turbulence model, which is modified for engine flows. “wave” and “eddy break up” models are employed to predict combustion and spray process. the calculations ...

The non linear eddy viscosity models are good candidates for the simulation of turbulent flows of industrial interest. In fact these models allow to avoid the complexity of the second-order closure models, and to capture more physics than the classical two equation turbulence models based on the Boussinesq hypothesis. Non linear κ-ε turbulence models have been developed by the authors, in the f...

Numerical simulation of the turbulent flow around a triangular cylinder at Reynolds number of 45,000 is presented in this paper. A body force potential model is used to model the turbulent motion. This approach is able to model non-equilibrium turbulence accurately at a cost and complexity comparable to k-ε models. The numerical method used in this calculation is an unstructured staggered mesh ...

The present investigation concerns the development of advanced scalar turbulence modeling approaches and their application to the calculation of non-isothermal wall-bounded flow phenomena. A new scalar modeling technique based on scalar turbulent scales is proposed and implemented at a second-order modeling approach. Instead of the classical analogy concept between the mechanical and the scalar...

Film-cooling flows are characterized by a row of jets injected at an angle from the blade surface or endwalls into the heated crossflow. The resulting flowfield is quite complex, and accurate predictions of the flow and heat transfer have been difficult to obtain using traditional two-equation turbulence models employed with ReynoldsAveraged Navier–Stokes (RANS) solvers. Recently, a four-equati...

The aim of this paper is numerical and experimental study of the effects of flow hydraulics, pipe structure (particularly elastic behaviour) and submerged jet on leak behaviour. In this regard, experimental tests were performed on a high-pressure circulation set up. Experiments were performed on an old steel pipe and a High Density Polyethylene (HDPE) pipe discharged to the atmosphere in a wide...

This work presents results of flow simulations performed with the commercial code CFX 11.0 in a PWR 5x5 rod bundle segment with a split vane spacer grid. The geometrical configuration and flow conditions used in the experimental studies performed by Karoutas were assumed in the simulations. To make the simulation possible with a limited computational capacity and acceptable mesh refinement, the...

Mist cooling concept has been considered for cooling turbine airfoils for many years. This concept has been proven experimentally as an effective method to significantly enhance the cooling effectiveness with several fundamental studies in the laboratory under low pressure and temperature conditions. However, it is not certain the same performance can be harnessed in the real gas turbine enviro...

The liquid-gas operations in the stirred vessels can be a complex system to analyze because of the presence numerous parameters and operational conditions that effect its performance. Since the past decades, CFD analysis is gaining popularity and even replacing the need for extensive experimentation. The objective of this review is to establish the approaches and equations commonly used in CFD ...