Effect of Intake Port Bend Angle on Flow Field Inside the Cylinder of a DI Diesel Engine

2007 ◽  
Author(s):  
B. Jayashankara ◽  
V. Ganesan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Diesel Engine ◽  
Flow Field ◽  
Design Tool ◽  
Turbulent Intensity ◽  
Cfd Modeling ◽  
Bend Angle ◽  
Intake Port ◽  
Di Diesel Engine

This paper presents the computational fluid dynamics (CFD) modeling to study the effect of intake port bend angle on the flow field inside the cylinder of a direct injection (DI) diesel engine under motoring conditions. The flow characteristics of the engine are investigated under transient conditions. A single cylinder DI diesel engine with two direct intake ports whose outlet is tangential to the wall of the cylinder and two exhaust ports has been taken up for the study. Effect of intake port bend angle (20°, 30°, and 40°) on the flow field inside the cylinder has been investigated at an engine speed of 1000 rpm. The pre-processor GAMBIT is used for model preparation and commercial computational fluid dynamics code STAR-CD has been used for solution of governing equations and post processing the results. CFD results during both intake and compression strokes have been compared with experimental results of Payri et-al [7, 8]. The predicted swirl ratio, radial velocity and turbulent intensity variations at different crank angles and at different locations are discussed. Distribution of velocity and turbulence intensity inside the cylinder is also discussed. It is observed that the intake ports with 20° bend angle produce maximum swirl and also results in a slight decrease in volumetric efficiency compared to intake ports with 30° and 40° bend angles and there is no appreciable variation in turbulent intensity. Hence, for the better performance of a DI diesel engine, it is concluded that the intake ports with 20° bend angle is most appropriate and CFD is an effective design tool to develop more efficient DI diesel engines.

Simulation and Experimental Investigation of Variable Swirl Intake Port in DI Diesel Engine Using CFD

2006 ◽  
Author(s):  
J. David Rathnaraj ◽  
B. Jefferson Raja Bose ◽  
Michael N. Kumar
Keyword(s):  
Fluid Dynamics ◽  
Diesel Engine ◽  
Flow Field ◽  
Diesel Engines ◽  
Experimental Validation ◽  
Swirl Flow ◽  
Intake Port ◽  
Swirl Ratio ◽  
Port Design ◽  
Di Diesel Engine

Knowledge of the flow phenomena inside the cylinder is necessary for optimum design of the intake port and the piston cavity configurations. Recent trends in direct injection diesel engines have increased the need for clear understanding of the flow field, especially the swirl characteristics. The swirl flow is an essential parameter which affects the air fuel mixing, combustion efficiency and therefore the engine performance. The purpose of this study is to investigate the combustion, emission, spray and flow field phenomena of a D I diesel engine and to come up with a geometrical shape for a port and valve or valves that produce the optimum swirl ratio. The percentage opening of a helical port for the DI diesel engine is simulated and studied using Computational Fluid Dynamics with experimental validation. Steady flow rig experiments are most widely used to evaluate the swirl ratio of an intake port design. The three dimensional developing flow patterns are needed throughout the compression and combustion stroke to understand the various experimental results. Flow is simulated by solving governing equations, viz., conservation of mass and momentum using the simple-algorithm. Turbulence has been modeled by standard kφ–φ∈ model with standard wall treatment. The predictive accuracy of the calculation method is compared with detailed mass flow rate and paddle rpm measurements. The results are in good agreement with experimental results and clearly predict the under predictability of the paddle swirl meter in lower lifts. Emission standards, which demand large reduction in NOx and PM emission, require a more comprehensive study of all elements that contribute to emission formulation. The combustion chamber is subject of research and development in an effort to achieve optimized combustion system. The intake port fluid dynamics contribute to the fuel air mixing which in turn is the most important parameter for the control of fuel burning rate for diesel engines. The intake port fluid dynamics also significantly affects ignition delay, the magnitude and timing of the diffusion burn, the magnitude of the premixed burn and emission of nitrous oxide and soot. According to the Modulated Kinetics (MK) concept, which improves the emission performance of diesel engines, a D I Diesel engine requires higher intake swirl in the part-load region. The computations are used to optimize the swirl flow characteristics of an intake port system over a wide range of operating conditions. In this study, the numerical simulation of the helical intake port and variable swirl intake port for two-valve DI Diesel engines are discussed with experimental validation. The improvement of swirl generation capacity of the port design according to the stringent emission norms are also studied.

Extent, capacity and possibilities of computational fluid dynamics as a design tool for pump intakes: a review

2018 ◽  
Vol 18 (5) ◽  
pp. 1518-1530 ◽  
Author(s):  
Jie Zhang ◽  
Tien Yee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Design Tool ◽  
Cfd Modeling ◽  
Cfd Simulations ◽  
Pump Station ◽  
Computational Fluid Dynamics Cfd ◽  
Future Direction ◽  
Computational Resources

Abstract Flow near pump intakes is three-dimensional in nature, and is affected by many factors such as the geometry of the intake bay, uniformity of approach flow, critical submergence, placements and operation combinations of pumps and so on. In the last three decades, advancement of numerical techniques coupled with the increase in computational resources made it possible to conduct computational fluid dynamics (CFD) simulations on pump intakes. This article reviews different aspects involved in CFD modeling of pump station intakes, outlines the challenges faced by current CFD modelers, and provides an attempt to forecast future direction of CFD modeling of pump intakes.

Flow field prediction in full-scale Carrousel oxidation ditch by using computational fluid dynamics

2010 ◽  
Vol 62 (2) ◽  
pp. 256-265 ◽  
Author(s):  
Yin Yang ◽  
Yingying Wu ◽  
Xiao Yang ◽  
Kai Zhang ◽  
Jiakuan Yang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Full Scale ◽  
Hydrodynamic Performance ◽  
Cfd Modeling ◽  
Oxidation Ditch ◽  
Wall Model ◽  
Moving Wall ◽  
Carrousel Oxidation Ditch

In order to optimize the flow field in a full-scale Carrousel oxidation ditch with many sets of disc aerators operating simultaneously, an experimentally validated numerical tool, based on computational fluid dynamics (CFD), was proposed. A full-scale, closed-loop bioreactor (Carrousel oxidation ditch) in Ping Dingshan Sewage Treatment Plant in Ping Dingshan City, a medium-sized city in Henan Province of China, was evaluated using CFD. Moving wall model was created to simulate many sets of disc aerators which created fluid motion in the ditch. The simulated results were acceptable compared with the experimental data and the following results were obtained: (1) a new method called moving wall model could simulate the flow field in Carrousel oxidation ditch with many sets of disc aerators operating simultaneously. The whole number of cells of grids decreased significantly, thus the calculation amount decreased, and (2) CFD modeling generally characterized the flow pattern in the full-scale tank. 3D simulation could be a good supplement for improving the hydrodynamic performance in oxidation ditch designs.

scholarly journals Studies on variable swirl intake system for DI diesel engine using computational fluid dynamics

2008 ◽  
Vol 12 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Rathnaraj Jebamani ◽  
Narendra Kumar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Diesel Engine ◽  
Steady Flow ◽  
High Speed ◽  
Mixing Time ◽  
Operating Conditions ◽  
Swirl Ratio ◽  
Partial Load ◽  
Di Diesel Engine

It is known that a helical port is more effective than a tangential port to attain the required swirl ratio with minimum sacrifice in the volumetric efficiency. The swirl port is designed for lesser swirl ratio to reduce emissions at higher speeds. But this condition increases the air fuel mixing time and particulate smoke emissions at lower speeds. Optimum swirl ratio is necessary according to the engine operating condition for optimum combustion and emission reduction. Hence the engine needs variable swirl to enhance the combustion in the cylinder according to its operating conditions, for example at partial load or low speed condition it requires stronger swirl, while the air quantity is more important than the swirl under very high speed or full load and maximum torque conditions. The swirl and charging quantity can easily trade off and can be controlled by the opening of the valve. Hence in this study the steady flow rig experiment is used to evaluate the swirl of a helical intake port design for different operating conditions. The variable swirl plate set up of the W06DTIE2 engine is used to experimentally study the swirl variation for different openings of the valve. The sliding of the swirl plate results in the variation of the area of inlet port entry. Therefore in this study a swirl optimized combustion system varying according to the operating conditions by a variable swirl plate mechanism is studied experimentally and compared with the computational fluid dynamics predictions. In this study the fluent computational fluid dynamics code has been used to evaluate the flow in the port-cylinder system of a DI diesel engine in a steady flow rig. The computational grid is generated directly from 3-D CAD data and in cylinder flow simulations, with inflow boundary conditions from experimental measurements, are made using the fluent computational fluid dynamics code. The results are in very good agreement with experimental results.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

Construction Ventilation Scheme Optimization of Underground Main Powerhouse Based on CFD

2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Air Flow ◽  
Scheme Optimization ◽  
Pressure Distributions ◽  
Air Volume ◽  
Computational Fluid Dynamics Cfd ◽  
Traditional Construction ◽  
Ventilation Scheme

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.

scholarly journals Effect of Doppler flow meter position on discharge measurement in surcharged manholes

2017 ◽  
Vol 77 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Haoming Yang ◽  
David Z. Zhu ◽  
Yanchen Liu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Flow Regimes ◽  
Flow Meter ◽  
Flow Meters ◽  
Flow Discharge ◽  
Doppler Flow ◽  
Sewer Systems ◽  
Computational Fluid Dynamics Cfd

Abstract Determining the proper installation location of flow meters is important for accurate measurement of discharge in sewer systems. In this study, flow field and flow regimes in two types of manholes under surcharged flow were investigated using a commercial computational fluid dynamics (CFD) code. The error in measuring the flow discharge using a Doppler flow meter (based on the velocity in a Doppler beam) was then estimated. The values of the corrective coefficient were obtained for the Doppler flow meter at different locations under various conditions. Suggestions for selecting installation positions are provided.

The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulent Model ◽  
Simulation Results ◽  
Rsm Model ◽  
Dynamics Method ◽  
Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

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