科技英语写作文献阅读报告

科技英语写作文献阅读报告

姓名：___李清璇____

班级： A(5 ) 班 学号：___[1**********]4___

Title ：Comparison of Construction Method for DEM Simulation of Ellipsoidal Particles

I Introduction

1. Has the writer stated the topic and the purpose of the research? What is the topic? What is the purpose?

Yes.

The topic is compare the construction method of ellipsoidal particles.

The purpose is chose a best representation for ellipsoidal particles.

2. Has the writer expressed his hypothesis or thesis statement? What is the thesis or the hypothesis?

They assume three multielement particle models to represent the ellipsoidal particle.

because of the authors find the real particle is usually non-spherical in shape, so that it is urgently needed to develop the model for simulating non-spherical particles. Each particle consists of several overlapping spheres which are called elements. The advantage of this method is that an essentially analytical method can be used to calculate contact detection and force direction.

3. Has the writer given enough background information?

There are many studies about granular materials flow in moving bed by discrete element model method,but most of them are focused on the spherical particles,and little information on non-spherical particles has been reported yet.

4. Has the writer reviewed pertinent literature?

Actually no.

II Methods

What materials, equipment and methods are used in the research?

The test particle is black soybean.The tracer particle is lima-bean(gray).

The equipment is moving bed and video.

They used discrete element model method .

III Results

1. How did the writer present his data and findings?

Figure ,table

2. What were the findings of the research?

The average kinetic energy during the whole flowing time of 3-intersection-element representation is larger than that of 3-tangent-element representation. And the average kinetic energy of 5-element representation is larger than that of 3-intersection- element representation.

the rotational kinetic energy of 5-element representation is the largest, and that of the 3-tangent-element representation is the smallest. The reason may be the surface of 5-element representation is smoother and it has better rolling performance.

The average collision number of 3-intersection-element and 3-tangent-element representation is almost the same during the whole time interval, and the average collision number of 5-element representation is the largest. The reason is the collision of ellipsoidal particle is based on the collision of the element on the particle. So the more elements there are, the more collision there are.

The deformation is related to the restitution coefficient, contact model, normal stress and element diameter, etc. In the three simulations, the restitution coefficient is fixed value 0.59, and the spring-damping model is chosen as the contact model. So the different element diameter leads to different deformation.

The contact force is related to spring coefficient and element diameter. The spring coefficient is fixed value. So the contact force also depends on the element diameter, and has the same tendency as deformation depicted

It shows 5-element representation takes more computational time than that of the 3-intersection-element representation when the tracer particles discharged from the hopper from 550 mm position.

IV Discussion

1. Did the research support the hypothesis?

yes.

2. What interpretations can be made from the results?

Developing a DEM model to simulate the ellipsoidal particles flowing in the moving bed with continuous feeding and discharging.

V Conclusion

What conclusions has the writer drawn?

The 3-interaction-element representation is chosen in the simulation.