Based on the orthogonal experiment optimization of UAV wing bionic airfoil design

2015 ◽  
pp. 109-116
Keyword(s):  
Orthogonal Experiment ◽  
Bionic Airfoil

PARAMETER OPTIMIZATION AND EXPERIMENTAL RESEARCH ON THE HAMMER MILL 锤片式粉碎机参数优化与试验研究

2020 ◽  
pp. 341-350
Author(s):  
Di Wang ◽  
Changbin He ◽  
Haiqing Tian ◽  
Liu Fei ◽  
Zhang Tao ◽  
...  
Keyword(s):  
Moisture Content ◽  
Orthogonal Experiment ◽  
Electricity Consumption ◽  
Spindle Speed ◽  
Hammer Mill ◽  
Factors Affecting ◽  
Evaluation Indexes ◽  
Grain Moisture ◽  
Validation Experiment ◽  
Corn Grain

Low productivity and high electricity consumption are considered problems of the hammer mill, which is widely used in current feed production. In this paper, the mechanical properties of corn grain ground by a hammer mill were analysed, and the key factors affecting the performance of the hammer mill were determined. The single-factor experiment and three-factor, three-level quadratic regression orthogonal experiment were carried out with the spindle speed, corn grain moisture content and number of hammers as experimental factors and the productivity and electricity consumption per ton as evaluation indexes. The results showed that the order of influence on the productivity was spindle speed > corn grain moisture content > number of hammers and that the order of influence on the electricity consumption per ton was corn grain moisture content > spindle speed > number of hammers. The parameters were optimized based on the response surface method with the following results: the spindle speed was 4306 r/min, the corn grain moisture content was 10%, and the number of hammers was 24. The validation experiment was carried out with the optimal parameters’ combination. The productivity and electricity consumption per ton were 988.12 kg/h and 5.37 kW·h/t, respectively, which were consistent with the predicted results of the model.

3D Finite Element Simulation for Turning of Hardened 45 Steel

2019 ◽  
Vol 13 (2) ◽  
pp. 181-188
Author(s):  
Meng Liu ◽  
Guohe Li ◽  
Xueli Zhao ◽  
Xiaole Qi ◽  
Shanshan Zhao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cutting Force ◽  
Finite Element Simulation ◽  
Orthogonal Experiment ◽  
Element Model ◽  
3D Finite Element ◽  
Element Simulation ◽  
Metal Machining ◽  
Single Factor Experiment

Background: Finite element simulation has become an important method for the mechanism research of metal machining in recent years. Objective: To study the cutting mechanism of hardened 45 steel (45HRC), and improve the processing efficiency and quality. Methods: A 3D oblique finite element model of traditional turning of hardened 45 steel based on ABAQUS was established in this paper. The feasibility of the finite element model was verified by experiment, and the influence of cutting parameters on cutting force was predicted by single factor experiment and orthogonal experiment based on simulation. Finally, the empirical formula of cutting force was fitted by MATLAB. Besides, a lot of patents on 3D finite element simulation for metal machining were studied. Results: The results show that the 3D oblique finite element model can predict three direction cutting force, the 3D chip shape, and other variables of metal machining and the prediction errors of three direction cutting force are 5%, 9.02%, and 8.56%. The results of single factor experiment and orthogonal experiment are in good agreement with similar research, which shows that the model can meet the needs for engineering application. Besides, the empirical formula and the prediction results of cutting force are helpful for the parameters optimization and tool design. Conclusion: A 3D oblique finite element model of traditional turning of hardened 45 steel is established, based on ABAQUS, and the validation is carried out by comparing with experiment.

scholarly journals A candidate gene identified in converting platycoside E to platycodin D from Platycodon grandiflorus by transcriptome and main metabolites analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinglong Su ◽  
Yingying Liu ◽  
Lu Han ◽  
Zhaojian Wang ◽  
Mengyang Cao ◽  
...  
Keyword(s):  
Candidate Gene ◽  
Orthogonal Experiment ◽  
Triterpenoid Saponin ◽  
Gene Encoding ◽  
Triterpenoid Saponins ◽  
Platycodin D ◽  
Polysaccharide Content ◽  
Saponin Biosynthesis ◽  
Polysaccharide Synthesis ◽  
Experimental Use

AbstractPlatycodin D and platycoside E are two triterpenoid saponins in Platycodon grandiflorus, differing only by two glycosyl groups structurally. Studies have shown β-Glucosidase from bacteria can convert platycoside E to platycodin D, indicating the potential existence of similar enzymes in P. grandiflorus. An L9(34) orthogonal experiment was performed to establish a protocol for calli induction as follows: the optimal explant is stems with nodes and the optimum medium formula is MS + NAA 1.0 mg/L + 6-BA 0.5 mg/L to obtain callus for experimental use. The platycodin D, platycoside E and total polysaccharides content between callus and plant organs varied wildly. Platycodin D and total polysaccharide content of calli was found higher than that of leaves. While, platycoside E and total polysaccharide content of calli was found lower than that of leaves. Associating platycodin D and platycoside E content with the expression level of genes involved in triterpenoid saponin biosynthesis between calli and leaves, three contigs were screened as putative sequences of β-Glucosidase gene converting platycoside E to platycodin D. Besides, we inferred that some transcription factors can regulate the expression of key enzymes involved in triterpernoid saponins and polysaccharides biosynthesis pathway of P. grandiflorus. Totally, a candidate gene encoding enzyme involved in converting platycoside E to platycodin D, and putative genes involved in polysaccharide synthesis in P. grandiflorus had been identified. This study will help uncover the molecular mechanism of triterpenoid saponins biosynthesis in P. grandiflorus.

Numerical study on the airfoil self-noise of three owl-based wings with the trailing-edge serrations

2021 ◽  
pp. 095441002098822
Author(s):  
Dian Li ◽  
Xiaomin Liu ◽  
Lei Wang ◽  
Fujia Hu ◽  
Guang Xi
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Numerical Study ◽  
Barn Owl ◽  
Aerodynamic Noise ◽  
Frequency Noise ◽  
Trailing Edge ◽  
Reduction Mechanisms ◽  
Trailing Edge Serrations ◽  
Bionic Airfoil

Previous publications have summarized that three special morphological structures of owl wing could reduce aerodynamic noise under low Reynolds number flows effectively. However, the coupling noise-reduction mechanism of bionic airfoil with trailing-edge serrations is poorly understood. Furthermore, while the bionic airfoil extracted from natural owl wing shows remarkable noise-reduction characteristics, the shape of the owl-based airfoils reconstructed by different researchers has some differences, which leads to diversity in the potential noise-reduction mechanisms. In this article, three kinds of owl-based airfoils with trailing-edge serrations are investigated to reveal the potential noise-reduction mechanisms, and a clean airfoil based on barn owl is utilized as a reference to make a comparison. The instantaneous flow field and sound field around the three-dimensional serrated airfoils are simulated by using incompressible large eddy simulation coupled with the FW-H equation. The results of unsteady flow field show that the flow field of Owl B exhibits stronger and wider-scale turbulent velocity fluctuation than that of other airfoils, which may be the potential reason for the greater noise generation of Owl B. The scale and magnitude of alternating mean convective velocity distribution dominates the noise-reduction effect of trailing-edge serrations. The noise-reduction characteristic of Owl C outperforms that of Barn owl, which suggests that the trailing-edge serrations can suppress vortex shedding noise of flow field effectively. The trailing-edge serrations mainly suppress the low-frequency noise of the airfoil. The trailing-edge serration can suppress turbulent noise by weakening pressure fluctuation.

scholarly journals Cost optimization of sodium hypochlorite bleaching washing for denim by combining ensemble of surrogates with particle swarm optimization

2021 ◽  
Vol 16 ◽  
pp. 155892502110223
Author(s):  
Jie Xu ◽  
Feng Liu ◽  
Zhenglei He ◽  
Zongao Zhang ◽  
Sheng Li
Keyword(s):  
Particle Swarm Optimization ◽  
Sodium Hypochlorite ◽  
Production Cost ◽  
Orthogonal Experiment ◽  
Cost Optimization ◽  
Particle Swarm ◽  
Process Variables ◽  
Swarm Optimization ◽  
Washing Process ◽  
Ensemble Of Surrogates

Sodium hypochlorite bleaching washing process has been broadly carried out in denim garment industrial production. However, the quantitative relationships between process variables and bleaching performances have not been illustrated explicitly. Hence, it is impractical to determine values of the variables that can achieve the optimal production cost while satisfying the requirements of customers. This paper proposes an optimization methodology by combining ensemble of surrogates (ESs) with particle swarm optimization (PSO) to optimize production cost of chlorine bleaching for denim. The methodology starts from the data collections by conducting a Taguchi L25 (56) orthogonal experiment with the process variables and metrics for evaluating bleaching performances. Based on the data, the quantitative relationships are separately constructed by using RBFNN, SVR, RF and ensemble of them. Then, accuracies of the surrogates are evaluated and it proves that the ESs outperforms the others. Later, the production cost optimization model is proposed and PSO is utilized to solve it, while a case study is given to depict the optimization process and verify the effectiveness of the proposed hybrid ESs-PSO approach. Overall, the ESs-PSO approach shows great capability of optimizing production cost of sodium hypochlorite bleaching washing for denim.

Fabrication of highly stable and durable furfurylated wood materials. Part I: process optimization

Holzforschung ◽  
2020 ◽  
Vol 74 (12) ◽  
pp. 1135-1146
Author(s):  
Wanju Li ◽  
Minghui Liu ◽  
Hankun Wang ◽  
Yan Yu
Keyword(s):  
Orthogonal Experiment ◽  
Weight Percent Gain ◽  
Weight Percent ◽  
Chinese Fir ◽  
Curing Temperature ◽  
Modulus Of Rupture ◽  
Scale Production ◽  
Range Analysis ◽  
Decay Fungi ◽  
Mold Resistance

AbstractIn order to improve dimensional stability and durability of wood, furfurylation of poplar and Chinese fir wood using newly developed furfuryl alcohol (FA) formulation combined with a common vacuum and pressure impregnation process was studied. An orthogonal experiment was designed to optimize the furfurylation process for the two wood species. The weight percent gain (WPG), equilibrium moisture content (EMC), anti-swelling efficiency (ASE), modulus of rupture (MOR), modulus of elasticity (MOE), as well as resistance to mold, decay fungi, and termites were evaluated. The results showed that nearly all the properties of the furfurylated wood could be improved to various extents. The average ASE of the furfurylated Chinese fir and poplar could reach as high as 80, 71, 92% and 79, 90, 75% in tangential and radial directions, and by volume, respectively, higher than most previously reported wood modification processes. Furthermore, the modified wood had excellent biological durability, with nearly 100% mold resistance, strong decay and termite resistance. Finally, processing parameters with 50% FA, 105–115 °C curing temperature, and 5–8 h curing time were therefore recommended for pilot-scale production of furfurylated poplar and Chinese fir wood based on range analysis.

scholarly journals Deviation Tolerance Performance Evaluation and Experiment of Picking End Effector for Famous Tea

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 128
Author(s):  
Yingpeng Zhu ◽  
Chuanyu Wu ◽  
Junhua Tong ◽  
Jianneng Chen ◽  
Leiying He ◽  
...  
Keyword(s):  
Success Rate ◽  
Negative Pressure ◽  
Evaluation Method ◽  
Orthogonal Experiment ◽  
Spatial Position ◽  
End Effector ◽  
Significance Level ◽  
Growth Environment ◽  
End Effectors ◽  
Average Success Rate

Accurately obtaining the posture and spatial position of tea buds through machine vision and other technologies is difficult due to the small size, different shapes, and complex growth environment of tea buds. Therefore, end effectors are prone to problems, such as picking omission and picking error. This study designs a picking end effector based on negative pressure guidance for famous tea. This end effector uses negative pressure to guide tea buds in a top-down manner, thereby correcting their posture and spatial position. Therefore, the designed end effector has deviation tolerance performance that can improve the picking success rate. The pre-experiment is designed, the tip of apical bud is referred to as the descent position, and the negative pressure range is determined to be 0.6 to 0.9 kPa. A deviation tolerance orthogonal experiment is designed. Experimental results show that various experimental factors are ranked in terms of the significance level of the effect on the average success rate, and the significance ranking is as follows: negative pressure (P) > pipe diameter (D) > descent speed (V). An evaluation method of deviation tolerance performance is presented, and the optimal experiment factor-level combination is determined as: P = 0.9 kPa, D = 34 mm, V = 20 mm/s. Within the deviation range of a 10 mm radius, the average success rate of the negative pressure guidance of the end effector is 97.36%. The designed end effector can be applied to the intelligent picking of famous tea. This study can provide a reference for the design of similar picking end effectors for famous tea.

scholarly journals Laboratory Investigation of Compaction Characteristics of Plant Recycled Hot-Mix Asphalt Mixture

2021 ◽  
Vol 13 (6) ◽  
pp. 3005
Author(s):  
Jiangang Yang ◽  
Chen Sun ◽  
Wenjie Tao ◽  
Jie Gao ◽  
Bocheng Huang ◽  
...  
Keyword(s):  
Regression Model ◽  
Hot Mix Asphalt ◽  
Orthogonal Experiment ◽  
Asphalt Mixture ◽  
Material Design ◽  
Void Content ◽  
Range Analysis ◽  
Aggregate Gradation ◽  
Compaction Characteristics ◽  
Compaction Energy

In this study, the compaction characteristics of recycled hot-mix asphalt (RHMA) were evaluated using the void content (VV), compaction energy index (CEI), slope of accumulated compaction energy (K), and lock point (LP). Then, the effects of the compaction parameters, including the gradation of the RHMA, reclaimed asphalt pavement (RAP) content, temperature of gyrations, and number of gyrations, on the compaction characteristics of RHMA were investigated. An orthogonal experiment was designed and the data collected were analyzed via range analysis; then, a regression model was generated relying on a quadratic polynomial. Furthermore, the regression model was used for the comparison and prediction of the mixture’s compactability during the material design. Finally, the compaction mechanism of RHMA was discussed from the perspective of the void content of RAP particles. The results showed that a finer aggregate gradation, a higher gyration temperature, a greater number of gyrations, and a higher RAP content were effective for increasing the compactability of RHMA. The range analysis results suggest that the gradation of RHMA has the greatest influence on compactability, followed by the RAP content. The RAP aggregate cannot diffuse to a new mixture completely, so the remained RAP particle reduces the void content of RHMA. Therefore, a higher RAP content up to 50% can help RHMA to achieve the designed void content with higher efficiency.

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