Numerical Investigation on Primary Atomization of the Fuel Spray in Diesel Engines

2012 ◽  
Vol 516-517 ◽  
pp. 634-637
Author(s):  
Zhi Xia He ◽  
Li Li Tian ◽  
Ju Yan Liu

In addition to the aerodynamic effects, turbulence and cavitation play an important role on the primary atomization. Different spray breakup models were analysized and evaluated though simulation of spray with them and then a new model of coupling the nozzle cavitating and turbulence flow to the spray primary breakup was put forward. The numerical simulation results with all these different spray primary breakup models were comparied with the experimental data and then the new model were proved to be much better. The study may effectively help establish the accurate spray breakup model.

2012 ◽  
Vol 256-259 ◽  
pp. 2543-2547
Author(s):  
Yi Min Xu ◽  
Yao Wang ◽  
Ji Rui Hou ◽  
Hua Qiang Wu ◽  
Xian Dong Liu ◽  
...  

For a flow chute with complex boundary conditions, such as with an anti-arc section, the flow behaviors and characteristics of aeration after the aerator are more complex than that in the straight chute. Based on the k~ε turbulence flow model together with VOF method, flow velocity fields over the aerator on the chute with anti-arc section were numerical simulated. Model experiments were investigated to verify the simulation results. Comparison shows that the calculation results agree well with the observed experimental data. Some factors including radius of the anti arc, aerator’s height and takeoff angel which influence aerated flow are discussed.


2011 ◽  
Vol 19 (03) ◽  
pp. 177-183 ◽  
Author(s):  
JIN-BO CHEN ◽  
QING-GANG QIU

The technique of horizontal-tube falling film has been used in the cooling and heating industries such as refrigeration systems, heating systems and ocean thermal energy conversion systems. The comprehensive performance of evaporator is directly affected by the film distribution characteristics outside tubes. In this paper, numerical investigation was performed to predict the film characteristics outside the tubes in horizontal-tube falling film evaporator. The effects of liquid flow rate, tube diameter and the circular degree of tube on the film thickness were presented. The numerical simulation results were compared with that of the empirical equations for calculating the falling film thickness, and agreements between them were reasonable. Numerical simulation results show that, at the fixed fluid flow density, the liquid film is thicker on the upper and lower tube and the thinnest liquid film appears at angle of about 120°. The results also indicate that, when the fluid flow density decreases to a certain value, the local dryout spot on the surface of the tube would occur. In addition, the film thickness decreases with the increases of the tube diameter at the fixed fluid flow density.


2000 ◽  
Author(s):  
Fahua Gu ◽  
Abraham Engeda ◽  
Mike Cave ◽  
Jean-Luc Di Liberti

Abstract A numerical simulation is performed on a single stage centrifugal compressor using the commercially available CFD software, CFX-TASCflow. The steady flow is obtained by circumferentially averaging the exit fluxes of the impeller. Three runs are made at design condition and off-design conditions. The predicted performance is in agreement with experimental data. The flow details inside the stationary components are investigated, resulting in a flow model describing the volute/diffuser interaction at design and off-design conditions. The recirculation and twin vortex structure are found to explain the volute loss increase at lower and higher mass flows, respectively.


2014 ◽  
Vol 529 ◽  
pp. 102-107
Author(s):  
Hai Bo Luo ◽  
Ying Yan ◽  
Xiang Ji Meng ◽  
Tao Tao Zhang ◽  
Zu Dian Liang

A 7.8m/s vertical drop simulate of a full composite fuselage section was conducted with energy-absorbing floor to evaluate the crashworthiness features of the fuselage section and to predict its dynamic response to dummies in future. The 1.52m diameter fuselage section consists of a high strength upper fuselage frame, one stiff structural floor and an energy-absorbing subfloor constructed of Rohacell foam blocks. The experimental data from literature [6] were analyzed and correlated with predictions from an impact simulation developed using the nonlinear explicit transient dynamic computer code MSC.Dytran. The simulated average acceleration did not exceed 13g, by contrast with experimental results, whose relative error is less than 11%. The numerical simulation results agree with experiments well.


2016 ◽  
Vol 10 (4) ◽  
pp. 310-315 ◽  
Author(s):  
Sławomir Duda ◽  
Damian Gąsiorek ◽  
Grzegorz Gembalczyk ◽  
Sławomir Kciuk ◽  
Arkadiusz Mężyk

Abstract This paper presents a novel mechatronic device to support a gait reeducation process. The conceptual works were done by the interdisciplinary design team. This collaboration allowed to perform a device that would connect the current findings in the fields of biomechanics and mechatronics. In the first part of the article shown a construction of the device which is based on the structure of an overhead travelling crane. The rest of the article contains the issues related to machine control system. In the prototype, the control of drive system is conducted by means of two RT-DAC4/PCI real time cards connected with a signal conditioning interface. Authors present the developed control algorithms and optimization process of the controller settings values. The summary contains a comparison of some numerical simulation results and experimental data from the sensors mounted on the device. The measurement data were obtained during the gait of a healthy person.


2013 ◽  
Vol 589-590 ◽  
pp. 3-7
Author(s):  
Kui Hu Cui ◽  
Cheng Zu Ren ◽  
Guang Chen

In this paper, an advanced 3D FE model was established using ABAQUS Explicit to simulate the process of milling aluminum-alloy 7075-T7451. Taking the end edge and the side edge of single flute into consideration, the model simulated the interaction between the spiral flute and wokpiece at full depth of cut. In addition, by defining automatic element deletion criterion and locally refining mesh, this model realized chip separating from workpiece without defining of cutting layer. The simulation results were compared with experimental data to verify the correctness of the simulation model.


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