First-principles Analysis of SiC/Al Composites Interface
Issue:
Volume 5, Issue 4, December 2019
Pages:
91-95
Received:
30 August 2019
Accepted:
7 October 2019
Published:
17 October 2019
Abstract: The interface of SiCp/Al composites is an important factor affecting the properties of materials, Different interface layers have different interface bonding strengths, which have different effects on the properties of SiCp/Al composites. In this paper, the possible binding energy of interface in SiCp/Al composites is studied, then the influence of the interfacial binding energy on the SiCp/Al composites is analyzed, and the method of controlling the interface of SiCp/Al composites is proposed. Firstly, three interface models that may exist in SiCp/Al composites were constructed in Material Studio software, and the model structure was optimized, then the first-principles simulation of the optimized interfaces model of SiCp/Al composites was carried out, and the interfacial bonding energy of SiC-Al, SiC-SiO2-Al and SiC-Al2O3-Al was calculated respectively. The order of the interfacial binding energy was: SiC(100)-Al(100) < SiC(100)-SiO2 (100)-Al(100) < SiC(100)-Al2O3 (100)-Al(100). It can be known from the simulation results that the interfacial bonding energy of the interface layer containing the oxide is large, since the oxide can improve the wettability between the matrix and the reinforcement. Therefore, in order to obtain a well-bonded SiCp/Al composite, the SiC particles are usually surface-modified to regulate the interface of the SiCp/Al composite. Thereby, the SiCp/Al composite material with high interface bonding strength and excellent performance is obtained.
Abstract: The interface of SiCp/Al composites is an important factor affecting the properties of materials, Different interface layers have different interface bonding strengths, which have different effects on the properties of SiCp/Al composites. In this paper, the possible binding energy of interface in SiCp/Al composites is studied, then the influence of...
Show More
Design System Development for a Fuel Cell Centrifugal Compressor
Cheng Xu,
Lei Chen,
Ryoichi Amano
Issue:
Volume 5, Issue 4, December 2019
Pages:
96-101
Received:
22 September 2019
Accepted:
22 October 2019
Published:
5 November 2019
Abstract: Centrifugal compressors have been used in many areas of the machinery. The centrifugal compressor design is very complex, and a unique design system needs to be developed. A centrifugal compressor design system should be easy to use in interface and also flexible for inputs and outputs. The design tool also needs to be able to predicate the compressor performance in a fairly accurate level. In this study, a centrifugal compressor design system which was developed in the past is further improved and developed. Current design system includes initial parameter studies, meanline analysis, throughflow calculation, impeller design, diffusser design, volute design, and structure analysis. The main improvements of the design system are adding the interface to allow users easy to use, adding the input and output capabilities and modifying few correlations. Current design system can predict the blade loading and compressor performance better compared with original design system. A fuel cell low flow and low specific speed centrifugal compressor is designed by using current design system and the prototype compressor is built. The compressor performance tests were conducted. The experimental results are compared with numerical analysis. The experiments are in good agreements with calculations. The results demonstrate that the centrifugal compressor design is successful and the design system can be used for the future centrifugal compressor designs.
Abstract: Centrifugal compressors have been used in many areas of the machinery. The centrifugal compressor design is very complex, and a unique design system needs to be developed. A centrifugal compressor design system should be easy to use in interface and also flexible for inputs and outputs. The design tool also needs to be able to predicate the compres...
Show More
MHD Mixed Convection Flow in a Lid Driven Enclosure with a Sinusoidal Wavy Wall and a Heated Circular Body
Kakali Chowdhury,
Abdul Alim
Issue:
Volume 5, Issue 4, December 2019
Pages:
102-110
Received:
19 August 2019
Accepted:
28 October 2019
Published:
6 November 2019
Abstract: MHD mixed convection flow in a lid driven enclosure with a sinusoidal wavy wall and heated circular body located at the center of the enclosure is studied numerically using finite element analysis. The upper wall is moving with a uniform velocity by unity, and other walls are in no slip condition. The enclosure vertical walls are insulated while the heated circular body inside the enclosure is maintained at a uniform temperature higher than the upper wall and lower wavy surface. Calculations are carried out through solving governing equations for different parameters by using finite element method. The investigation is conducted for various values of Richardson number Ri and Prandtl number Pr. The heat transfer characteristics and flow pattern inside the enclosure are presented in the form of streamlines and isothermal contours. Heat transfer rate in terms of the average Nusselt number and average fluid temperature inside the enclosure are presented for different parameters. The results indicate that the average Nusselt number at the heated surface and average temperature of the fluid inside the enclosure are strongly dependent on the configuration of the system under different geometrical and physical conditions.
Abstract: MHD mixed convection flow in a lid driven enclosure with a sinusoidal wavy wall and heated circular body located at the center of the enclosure is studied numerically using finite element analysis. The upper wall is moving with a uniform velocity by unity, and other walls are in no slip condition. The enclosure vertical walls are insulated while th...
Show More
