in order to comply with stringent pollutant emissions regulations, a detailed analysis of the engine combustion and emission is required. in this field, computational tools like cfd and engine cycle simulation play a fundamental role. therefore, the goal of the present work is to simulate a high speed di diesel engine and study the combustion and major diesel engine emissions with more details,...

This work presents an approach to the analysis of duct-augmented wind turbines using Computational Fluid Dynamics (CFD). The main objective is find optimum duct shape and design that gives maximum boost performance turbines. A surrounding rotor able increase power coefficient above Betz limit, so it has attracted great attention for many years. In this work, extensive augmented presented, consi...

The Ahmed body is one of the most studied 3D automotive bluff bodies and variation its slant angle rear upper surface generates different flow behaviours, similar to a standard road vehicles. In this study we extend geometrical evaluate influence underbody diffuser which are commonly applied in high performance race cars improve downforce. Parametric studies performed on two baseline configurat...

In this paper, numerical investigation of upward two phase flow of air-water has been studied. Different conditions of flow regimes including annular, wispy annular, slug, churn and bubbly are simulated based on Hewitt and Roberts map, and a good agreement between the experimental data of the map and the numerical simulation has been observed. Accordingly, a proper CFD model in CFD software of ...

This study focuses on the effect of surface coating on the impellers and diffusers in improving the efficiency of mixed flow submersible borewell pumps. It consists of two parts. In the first part, a 3 stage pump was constructed with uncoated bronze impellers and cast iron diffusers having a surface roughness value of 2.5μm Ra and tested for pump performance. Then the same 3 stage pump was test...

This study demonstrated how to use two simplified methods, the box and momentum methods, to simulate complex diffusers in room airflow modeling by computational fluid dynamics. The two methods require additional flow information that is not available from product catalogues of diffuser manufacturers. This information includes the distribution of discharge air velocity, box size, and flow direct...

Flow control has a tremendous technological and economic impact, such as aerodynamic drag reduction on road vehicles which translates directly into fuel savings, with consequent in greenhouse gas emissions operating costs. In recent years, machine learning also been used to develop new approaches flow place of more laborious methods, parametric studies, find optimal parameters few exceptions. T...

We develop a reduced order model for large-scale unsteadiness (vortex shedding) in a two-dimensional diffuser and study the mechanisms of active flow separation control. This model can estimate the vortex shedding frequency for inviscid flows by accounting for the accumulated vorticity flux in the diffuser. The model can also predict the stagnation pressure loss, which consists of two parts: A ...

Surface-Piercing Propellers (SPPs) have been widely used in high speed craft due to some desirable features such as high efficiency, omission of resistance of equipment attached to the propeller and proper functioning of cavitation. Unlike the submerged propellers, theoretical methods have no significant application on simulation of SPPsbecause of problems related to modeling of these propeller...