Three-Dimensional Simulation of the Intake Port Combination Effect on Intake Flow Characteristic in a Highly Intensified Diesel Engine

2013 ◽  
Vol 744 ◽  
pp. 211-214
Author(s):  
Hong Meng Li ◽  
Guo Xiu Li ◽  
Yuan Jing Hou ◽  
Yu Song Yu

In this paper, the three-dimensional CFD method is used in numerical simulation of the highly intensified diesel engine intake process. The effect of different intake flow compound modes on the highly intensified diesel engine is studied (Including compounded port with helical and tangential intake port, compounded port with two helical intake ports and compounded port with two tangential intake ports). By contrasting the instantaneous flow field, flow characteristic and inlet ability of the three compound modes, the pattern of influence on the inlet flow characteristics by compound modes is analyzed. The results indicate that the combinations of the intake port greatly affect the swirl rate and the inlet ability. The interference of the two helical intake ports is serious, causing more inlet loss. The two helical intake ports have the weakest inlet ability among the three types of intake ports. However, two helical intake ports can cause higher swirl rate. Two tangential intake ports inlet ability is the most excellent, but its swirl rate is the lowest.

2021 ◽  
pp. 163-172
Author(s):  
Junxiang Gao ◽  
Xiaoliang Gao ◽  
Wei Zou

Taking the lubrication system of rotary tillage engine as the research object, this paper makes a three-dimensional simulation study on the oil flow characteristics in the lubricating oil passage. The oil supply of the oil pump shall be greater than the circulating oil required by the lubrication system to ensure the lubrication of the rotary cultivator. Lubrication system is an important part to ensure the reliability and durability of rotary cultivator. The key component to achieve its performance is the oil pump. The geometric model of lubricating oil flow field in rotary tiller lubrication system is established by using FLUENT software. The results show that the pressure drop in the lubricating oil passage of the main bearing is the largest under the same working conditions. In the oil passage of the cylinder head, the pressure drop of the front main oil passage is the largest and the oil discharge is the largest. Add 1.6mm oil pump rotor on the basis of the thickness of the original oil pump rotor, the oil flow at the connecting rod nozzle reaches the flow index of the original rotary cultivator, and there is no cylinder pulling phenomenon of the rotary cultivator.


Author(s):  
A. Abd El-Sabor Mohamed ◽  
Saleh Abo-Elfadl ◽  
Abd El-Moneim M. Nassib

The in-cylinder airflow motion is an important factor that severely affects combustion efficiency and emissions in diesel engines. It is greatly affected by the inlet port and valve geometries. A diesel engine cylinder with a helical–spiral inlet port is used in this study. An ordinary inlet valve and shrouded inlet valve having different shroud and orientation angles are used to study the shroud effect on the swirl and tumble motion inside the engine cylinder. Four shroud angles of 90 deg, 120 deg, 150 deg, and 180 deg are used. With each shroud angle, four orientation angles of 0 deg, 30 deg, 60 deg, and 90 deg are also used. Three-dimensional simulation model using the shear stress transport (SST) k–ω model is used for simulating air flow through the inlet port, inlet valve, and engine cylinder during both the intake and compression strokes. The results showed that increasing the valve shroud angle increases the swirl, and the maximum increase occurs at a valve shroud angle of 180 deg and orientation angle of 0 deg with a value of 80% with respect to the ordinary valve. But it decreases the volumetric efficiency, and the maximum decrement occurs at valve shroud of 180 deg and orientation angle of 90 deg with a value of 5.98%. Variations of the shroud and orientation angles have very small effect on the tumble inside the engine cylinder.


Author(s):  
Qingguang Chen ◽  
Zhong Xu ◽  
Yulin Wu ◽  
Yongjian Zhang

Flow characteristics of turbulent impinging jets issuing, respectively, from a rectangular and a square nozzles have been investigated numerically through the solution of three-dimensional Navier-Strokes equations in steady state. Two geometries with two nozzle-to-plate spacings of four and eight times of hydraulic diameters of the jet pipes, and two Reynolds numbers of 20000 and 30000 have been considered with fully developed inlet boundary conditions. An RNG based k–ε turbulence model and a deferred correction QUICK scheme in conjunction with the wall function method have been applied to the prediction of the flow fields within semi-confined spaces. A common feature revealed by the computational results is the presence of a toroidal recirculation zone around the jet. An adverse pressure gradient is found at the impingement surface downstream the stagnation point. Boundary layer separation will occur if the gradient is strong enough, and the separation manifests itself as a secondary recirculation zone at the surface. In addition, three-dimensional simulations reveal the existence of two and four pronounced streamwise velocity off-center peaks at the cross-planes near to the impingement plate, respectively, in the rectangular and square impinging jet flows. These peaks are found forming at the horizontal planes where the wall jets start forming accompanied by two or four pairs of counter-rotating vortex rings. It is believed that the formation of the off-center velocity peaks is due to the vorticity diffusion along the wall jet as the jet impinges on the target plate.


2014 ◽  
Vol 1079-1080 ◽  
pp. 926-929
Author(s):  
Dan Han ◽  
Qian Wang ◽  
Bing Huan Li ◽  
Guo Jun Zhang ◽  
Shuo Wang

Intake port is an important part of the gasoline engine, its structure will influence the gas flow characteristics which directly affects the performance of the engine [1]. In this paper, three-dimensional CFD calculation and structural optimization were used to research the performance of gasoline engine. Firstly, the method of laser scanning and UG software were used to reverse modeling engine exhaust port and get the three-dimensional model. Secondly, after setting boundary conditions and turbulence models, the air flowing through the intake ports were simulated by FLUENT software respectively. Finally, based on numerical methods, the pressure field, velocity field were shown. The results of the simulation of flow field characteristics analysis show that the simulation and experimental results are in good agreement.


2020 ◽  
pp. 004051752098258
Author(s):  
Malik YH Saty ◽  
Nicholus Tayari Akankwasa ◽  
Jun Wang

The compact spinning system with a lattice apron utilizes air-flow dynamics to condense fibers in a bunch and enhance the yarn properties. One of the main challenges with this method is the lack of a comprehensive understanding of the air-flow field's effect in the condensing zone. This work presents a numerical and experimental investigation of the effects of three-dimensional (3D) printed guiding devices on the air-flow characteristics and yarn properties. Firstly, the 3D numerical model of the compact spinning system was set up based on the compact spinning machine geometrical dimensions. Secondly, different 3D prototypes were developed, simulated, and analyzed using computational fluid dynamics based on ANSYS software. The prototypes (A-type, B-type, and C-type), selected according to the simulation results, were then 3D printed to enable further experimental investigation. Air-flow analysis results in the air-suction flume area exhibiting a very high negative pressure, and the centerline zone was characterized by high velocity. Experimental results revealed that the three yarns spun with guiding devices had better strength, hairiness, and evenness than those spun without a guiding device. The model developed can be further improved and utilized for commercial purposes and is anticipated to improve compact spun yarn properties significantly.


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