Design of a novel flat-cloth airway in powder tank based on Taguchi optimization

Author(s):  
Fei Wang ◽  
Hao Yan ◽  
Yishan Zeng ◽  
Wei Xu ◽  
Haozhou Zang ◽  
...  

The fluidized bed is a key structure in the field of material transportation and is widely used in special automobile and construction powder transportation. A novel flat-cloth airway structure for powder unloading was proposed based on the traditional fluidized bed in this study. To analyze the uniformity of the velocity distribution ( Vu) in the fluidized bed and clarify the interaction mechanism between the geometric structure of the fluidized bed and airflow, 16 geometric structures of the fluidized bed for powder unloading were designed. Different schemes of the fluidized bed were numerically calculated by computational fluid dynamics, and the advantages of each scheme were analyzed by the Taguchi method and multiple regression. The length of the annular vortexes at the inlet of the airways becomes shorter than before as the number of airways increases. Airway height ( H), airway angle ( θ) and airway arc length ( L) exert statistically significant effects. Specifically, H (Delta = 6.45 rank =1) has the greatest effect on signal-to-noise ratios, L (Delta = 2.60 rank =2) has the second greatest effect and θ (Delta = 1.82 rank =3) has the least effect. The optimal combination of geometrical parameters of the fluidized bed is 15 mm H, 51° θ and 200 mm L.

Author(s):  
Fei Wang ◽  
Hao Yan ◽  
Yishan Zeng ◽  
Wei Xu ◽  
Haozhou Zang ◽  
...  

The gas–solid fluidized bed is the key structure of industrial fluidization, and it is widely used in fields such as chemical reactors and industrial material conveying. To study the uniformity of velocity distribution ( Vu) in a fluidized bed and clarify the interaction mechanism between the geometric structure of the air chamber and the gas flow, in this paper, 16 novel chamber structures for powder unloading were designed based on the Taguchi method. Computational fluid dynamics was used to simulate the different chamber schemes, and the effects of various geometric factors on the response were analyzed based on the Taguchi method. The effect of the novel optimization model for powder unloading was verified by tests. The results show that the optimal combination of geometrical parameters is air chamber capacity ( V) at level 4, separation ratio ( K) at level 1 and clearance of splitter plate ( δ) at level 1, and δ has the greatest effect on the Vu1 and Vu2 in the fluidized bed. With the increase in δ and K, the velocity of the airflow away from the inlet side increases, and the area of the vortex near the splitter plate increases. Compared with the baseline model, the fluidized bed with the novel air chamber can effectively reduce the residual rate of powder unloading.


Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2042
Author(s):  
Redha Boubenia ◽  
Patrice Le Moal ◽  
Gilles Bourbon ◽  
Emmanuel Ramasso ◽  
Eric Joseph

The paper deals with a capacitive micromachined ultrasonic transducer (CMUT)-based sensor dedicated to the detection of acoustic emissions from damaged structures. This work aims to explore different ways to improve the signal-to-noise ratio and the sensitivity of such sensors focusing on the design and packaging of the sensor, electrical connections, signal processing, coupling conditions, design of the elementary cells and operating conditions. In the first part, the CMUT-R100 sensor prototype is presented and electromechanically characterized. It is mainly composed of a CMUT-chip manufactured using the MUMPS process, including 40 circular 100 µm radius cells and covering a frequency band from 310 kHz to 420 kHz, and work on the packaging, electrical connections and signal processing allowed the signal-to-noise ratio to be increased from 17 dB to 37 dB. In the second part, the sensitivity of the sensor is studied by considering two contributions: the acoustic-mechanical one is dependent on the coupling conditions of the layered sensor structure and the mechanical-electrical one is dependent on the conversion of the mechanical vibration to electrical charges. The acoustic-mechanical sensitivity is experimentally and numerically addressed highlighting the care to be taken in implementation of the silicon chip in the brass housing. Insertion losses of about 50% are experimentally observed on an acoustic test between unpackaged and packaged silicon chip configurations. The mechanical-electrical sensitivity is analytically described leading to a closed-form amplitude of the detected signal under dynamic excitation. Thus, the influence of geometrical parameters, material properties and operating conditions on sensitivity enhancement is clearly established: such as smaller electrostatic air gap, and larger thickness, Young’s modulus and DC bias voltage.


Author(s):  
Pengfei Li ◽  
Fuquan Hu ◽  
Xuwei Wang ◽  
Zheng He ◽  
Zhi Gang

Focusing on the general and localized elastoplastic buckling of the cylindrical section of steel containment under axial pressure, nonlinear finite element method (FEM) and small-scaled experiments are applied to analysis. First, FEM analysis is conducted considering nonlinear items caused by geometric shape imperfection and elastoplastic constitutive model by the arc-length method RIKS procedure. Parameter sensitivity of the buckling is revealed. Then, small-scaled experiments are carried out. Buckles status is observed, and key geometrical parameters’ influence are found. The results show that cylindrical buckling under axial pressure is sensitive to geometrical parameters and imperfection. It is necessary to employ more realistic parameters to the FEM analysis via accurate geometrical measurement. This research has reference value for the design and fabrication of AP series steel containment vessel.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 835
Author(s):  
Tianyu Mao ◽  
Fengzhou Fang

The surface with high-aspect-ratio nanostructure is observed to possess the bactericidal properties, where the physical interaction between high-aspect-ratio nanostructure could exert sufficient pressure on the cell membrane eventually lead to cell lysis. Recent studies in the interaction mechanism and reverse engineering have transferred the bactericidal capability to artificial surface, but the biomimetic surfaces mimicking the topographical patterns on natural resources possess different geometrical parameters and surface properties. The review attempts to highlight the recent progress in bactericidal nanostructured surfaces to analyze the prominent influence factors and cell rupture mechanism. A holistic approach was utilized, integrating interaction mechanisms, material characterization, and fabrication techniques to establish inclusive insights into the topographical effect and mechano-bactericidal applications. The experimental work presented in the hydrogel material field provides support for the feasibility of potentially broadening applications in soft contact lenses.


2011 ◽  
Vol 337 ◽  
pp. 294-299
Author(s):  
Morteza Hosseinzadeh ◽  
S. Ali Zamani ◽  
Ali Taheri

During the last few years, several sheet hydroforming processes have been introduced. Despite the advantages of these methods, they have some limitations. Of the processes, the two main ones are the standard hydroforming and hydromechanical deep drawing. A new sheet hydroforming die set was proposed that has the advantages of both processes and eliminates their limitations. In this method, a polyurethane plate was used as a part of the die-set to control the blank holder force. This paper outlines the Taguchi optimization methodology, which is applied to optimize the effective parameters in forming cylindrical cups by the new die set of sheet hydroforming process. The process parameters evaluated in this research are polyurethane hardness, polyurethane thickness, forming pressure path and polyurethane hole diameter. The design of experiments based upon L9 orthogonal arrays by Taguchi was used and analysis of variance (ANOVA) was employed to analyze the effect of these parameters on the forming pressure. The analysis of the results showed that the optimal combination for low forming pressure is harder polyurethane, bigger diameter of polyurethane hole and thinner polyurethane. Finally, the confirmation test was derived based on the optimal combination of parameters and it was shown that the Taguchi method is suitable to examine the optimization process.


2018 ◽  
Vol 12 (4) ◽  
pp. 265-269
Author(s):  
Małgorzata Poniatowska

Abstract An optimization study using the design of experiment technique is described, in which the surface profile height of a freeform surface, determined in coordinate measurements, is the response variable. The control factors are coordinate sampling parameters, i.e. the sampling grid size and the measuring tip diameter. As a result of the research, an optimal combination of these parameters was found for surface mapping with acceptable measurement uncertainty. The presented study is the first stage of optimization of machining error correction for the freeform surface and was intended to take into account mechanical-geometric filtration of surface irregularities caused by these geometrical parameters. The tests were carried out on a freeform workpiece milled with specific machining parameters, Ra of the surface roughness was 1.62 μm. The search for the optimal combination of parameters was conducted using Statistica software.


2014 ◽  
Vol 472 ◽  
pp. 688-692
Author(s):  
Shu Wen Wang ◽  
Te Li Su

Polyester fibre is the synthetic fiber made with man-made fibers. Its surface is smooth with the texture of fine linen. It has good flexibility and durability and is the best non-iron fibres. In order to promote the accuracy and reduce the quality deviation of melt spinning, the Taguchi method was adopted in the melt spinning process. The aim of the research is to enhance the optimization of the melt spinning process using the material polyester. First, the Taguchi method is applied to establish the design of experiment. An analysis of variance will be done to arrive at the significant factors that influence the melt spinning quality the most. Lastly, confirmation experiments verified the reproducibility of this experiment. Confirmed by the experiments, results showed that the obtained SN ratios were greater than the signal-to-noise ratio of nine orthogonal array experiments and this means the experiment is reliable.


Mechanika ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 73-81
Author(s):  
Mustafa özdemir

In this study, springback behaviour of Dp600 (Dual Phase Steel) sheet material was investigated using air V bending technique.  As bending parameters, four different punch tip radii and four different sheet thicknesses were used. The springback values obtained from the experiments were compared with each other. At the same time, the experimental data were analysed with Response Surface Method (RSM) and Taguchi (L16) orthogonal array. The experimental data and the simulation results were found to be consistent. The signal-to-noise (S/N) ratio is used to determine the most appropriate parameter of minimum springback behaviour. Additionally, it is possible to estimate the optimal combination of the bending parameters. The signal-to-noise (S/N) ratio and the design of experiment (DOE) were utilised for the analysis of the experimental results. It was determined that the effect of these parameters on the air V bending process was based on springback behaviours.


2021 ◽  
Vol 11 (4) ◽  
pp. 1608
Author(s):  
Semyoung Oh ◽  
Daejin Park

Collaborative beamforming (CB) enables uplink transmission in a wireless sensor network (WSN) composed of sensors (nodes) and far-away access points (APs). It can also be applied to the case where the sensors are equipped with beam-switching structures (BSSs). However, as the antenna arrays of the BSSs are randomly headed due to the irregular mounting surface, some sensors form beams that do not illuminate a desired AP and waste their limited energy. Therefore, to resolve this problem, it is required to switch the beams toward the desired AP. While an exhaustive search can provide the globally optimal combination, a greedy search (GS) is utilized to solve this optimization problem efficiently. Simulation and experimental results verify that under certain conditions the proposed algorithm can drive the sensors to switch their beams properly and increase the received signal-to-noise ratio (SNR) significantly with low computational complexity and energy consumption.


2019 ◽  
Vol 84 ◽  
pp. 02012
Author(s):  
Antoni Sawicki

The paper presents the Schellhase and Pentegov models utilizing static voltage-current characteristics for representing processes occurring in the electric arc. In the approximations of these characteristics variation in geometrical parameters, i.e. arc length and cross-section is taken into account. A modification of the Voronin-type models is also proposed, introducing a static voltage-current characteristic. In this way, it is possible to take into account distortions of the arc geometrical parameters of the static and dynamic character.


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