Three-dimensional numerical simulation analysis on the combustion and emission characteristics of small non-road Diesel Engine fueled with bio-diesel

Author(s):  
Yin Bifeng ◽  
Guan Tao ◽  
Liu Shengji ◽  
Wei Qiang
2019 ◽  
Vol 35 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Qiang Shi ◽  
Hanping Mao ◽  
Xianping Guan

Abstract. To analyze the droplet deposition under the influence of the flow field of an unmanned aerial vehicle (UAV), a hand-held three-dimensional (3D) laser scanner was used to scan 3D images of the UAV. Fluent software was used to simulate the motion characteristics of droplets and flow fields under the conditions of a flight speed of 3 m/s and an altitude of 1.5 m. The results indicated that the ground deposition concentration in the nonrotor flow field was high, the spray field width was 2.6 m, and the droplet deposition concentration was 50 to 200 ug/cm2. Under the influence of the rotor flow field, the widest deposition range of droplets reached 12.8 m. Notably, the droplet deposition uniformity worsened, and the concentration range of the droplet deposition was 0 to 500 ug/cm2. With the downward development of the downwash flow field, the overall velocity of the flow field gradually decreased, and the influence interval of the flow field gradually expanded. In this article, the droplet concentration was verified under simulated working conditions by a field experiment, thereby demonstrating the reliability of the numerical simulation results. This research could provide a basis for determining optimal UAV operating parameters, reducing the drift of droplets and increasing the utilization rate of pesticides. Keywords: Unmanned aerial vehicle (UAV), Aerial application, Downwash flow field, Droplet deposition, Simulation analysis.


2012 ◽  
Vol 562-564 ◽  
pp. 1438-1441
Author(s):  
Li Hua Fu ◽  
Juan Juan Jiang ◽  
Dai Xing Zhang ◽  
Hai Quan Li ◽  
Hua Song ◽  
...  

In this article, the Pro/Engineer virtual prototyping technology is used for three dimensional entity modeling, assembly, and simulation analysis of 1000KN·m large backstop in four design plans to confirm the integrity and assembling of backstop. By using the ANSYS/LS-DYNA software, it makes numerical simulation analysis of the backstop in non-return process, and through the analysis comparison to the simulation result, it obtains the optimization design plan of the 1000KN·m backstop.


2013 ◽  
Vol 464 ◽  
pp. 375-380 ◽  
Author(s):  
Ling Liu ◽  
Chong Xin Liu ◽  
Yi Fan Liao

In this paper, a new five-dimensional hyperchaotic system by introducing two additional states feedback into a three-dimensional smooth chaotic system. With three nonlinearities, this system has more than one positive Lyapunov exponents. Based on the fractional derivative theory, the fractional-order form of this new hyperchaotic system has been investigated. Through predictor-corrector algorithm, the system is proved by numerical simulation analysis. Simulation results are provided to illustrate the performance of the fractional-order hyperchaotic attractors well.


2013 ◽  
Vol 634-638 ◽  
pp. 1655-1658
Author(s):  
Qiu Bo Huang ◽  
Qing Jie Liu ◽  
Sheng Ju Zang

The separation efficiency, separation factor, flow and other parameters are closely related in terms of horizontal spiral sedimentation centrifuge. This article takes lwb350 horizontal spiral sedimentation centrifuge for example, with the help of FLUENT software, the relationship among the separation efficiency and the working speed as well as feed flow is analyzed through the numerical simulation of solid-liquid separation, which can provide reference for the application of simulation analysis and research on properties of spiral centrifuge.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zizhen Miao ◽  
Shuguang Li ◽  
Jiangsheng Xie ◽  
Runke Huo ◽  
Fan Ding ◽  
...  

Due to its unique technological characteristics, coal mining and production often encounter an acid corrosion environment caused by acid gases. Acid erosion and a series of chemical reactions caused by it often led to the deterioration of coal, rock, support structure, etc. and induced serious safety accidents. To further explore the macro-mesoscopic damage evolution law and failure mechanisms of rock masses under corrosion conditions through numerical simulation, a zonal refined numerical model that can reflect the acid corrosion characteristics of sandstone is established based on CT and digital image processing (DIP). The uniaxial compression test of corroded sandstone is simulated by ABAQUS software. Comparing the numerical simulation results with the physical experiment results, we found that the three-dimensional finite element model based on CT scanning technology can genuinely reflect sandstone’s corrosion characteristic. The numerical simulation results of the stress-strain curve and macroscopic failure mode of the acid-corroded sandstone are in good agreement with the experimental results, which provides a useful method for further studying the damage evolution mechanism of the acid-corroded rock mass. Furthermore, the deformation and damage evolution law of the corroded sandstone under uniaxial compression is qualitatively analyzed based on the numerical simulation. The results show that the rock sample’s axial displacement decreases gradually from top to bottom under the axial load, and the vertical variation is relatively uniform. In contrast, the rock sample’s removal gradually increases with the increase of axial pressure, and the growth presents a certain degree of nonuniformity in the vertical. The acid-etched rock sample’s damage starts from both the end and the middle; it first appears in the corroded area. Moreover, with the displacement load increase, it gradually develops and is merged in the middle of the rock sample and forms macroscopic damage.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1527-1530
Author(s):  
Chun Jie Song ◽  
Cheng Fan

Based on a deep understanding of FLAC 3D numerical simulation software and the solid-liquid coupling theory and calculation method, this paper established a mining three-dimensional mechanical model under the pressurized water .Using the numerical simulation method, this paper systematically analysis deformation Laws of stress distribution of mining floor, bottom stress, its plastic zone and floor failure depth. By analyzing water inrush flow-solid coupling seepage problem under the conditions of coal mining, and compares with relevant information, verify the rationality of the existing theories and engineering measures, provide a theoretical basis for seeking security and economic exploitation of technical measures.


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