Optimization of Center of Gravity Position and Anti-Wave Plate Angle of Amphibious Unmanned Vehicle Based on Orthogonal Experimental Method

When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation characteristics.In the relevant research on reducing the navigation resistance of amphibious vehicles by adjusting the angle of the anti-wave plate,there is a lack of scientific selection of parameters and reasonable research of simulation results by using mathematical methods,and the influence of the center of gravity position on navigation characteristics is not considered at the same time.To study the influence of the combinations of the angle of the anti-wave plate and the position of the center of gravity on the resistance reduction characteristics,a numerical calculation model of the amphibious unmanned vehicle was established by using the theory of computational fluid dynamics,and the experimental data verified the correctness of the numerical model.Based on this numerical model,the navigation characteristics of the amphibious unmanned vehicle were studied when the center of gravity was located at different positions,and the orthogonal experimental design method was used to optimize the parameters of the angle of the anti-wave plate and the position of the center of gravity.The results show that through the parameter optimization analysis based on the orthogonal experimental method,the combination of the optimal angle of the anti-wave plate and the position of the center of gravity is obtained.And the numerical simulation result of resistance is consistent with the predicted optimal solution.Compared with the maximum navigational resistance,the parameter optimization reduces the navigational resistance of the amphibious unmanned vehicle by 24%.

A Spider Monkey Optimization Algorithm Combining Opposition-Based Learning and Orthogonal Experimental Design

As a new bionic algorithm,Spider Monkey Optimization(SMO)has been widely used in various complex optimization problems in recent years.However,the new space exploration power of SMO is limited and the diversity of the population in SMO is not abundant.Thus,this paper focuses on how to reconstruct SMO to improve its performance,and a novel spider monkey optimization algorithm with opposition-based learning and orthogonal experimental design(SMO^(3))is developed.A position updatingmethod based on the historical optimal domain and particle swarmfor Local Leader Phase(LLP)andGlobal Leader Phase(GLP)is presented to improve the diversity of the population of SMO.Moreover,an opposition-based learning strategy based on self-extremum is proposed to avoid suffering from premature convergence and getting stuck at locally optimal values.Also,a local worst individual elimination method based on orthogonal experimental design is used for helping the SMO algorithm eliminate the poor individuals in time.Furthermore,an extended SMO^(3)named CSMO^(3)is investigated to deal with constrained optimization problems.The proposed algorithm is applied to both unconstrained and constrained functions which include the CEC2006 benchmark set and three engineering problems.Experimental results show that the performance of the proposed algorithm is better than three well-known SMO algorithms and other evolutionary algorithms in unconstrained and constrained problems.

Optimization of extraction of polyphenols from pomegranate peel by orthogonal experiment design and antioxidant activity

The aim of this study was to investigate the extraction process and antioxidant activity of polyphenols from Yunnan Mengzi pomegranate peel.Single factor and orthogonal test were used as optimize the extract rate(ER)of polyphenols from pomegranate peel(PGP).The polyphenols antioxidant activity was evaluated by DPPH·,·OH and total reducing ability,and compared with that of Vc.The optimum extraction conditions of polyphenols were as follows:ethanol concentration of 50%,liquid-solid ratio of 50:1,extraction temperature of 90°C,extraction for 4 h.Under these conditions,the ER of polyphenols from GPG was 8.15%.The results showed that the scavenging effects of polyphenols and Vc on DPPH·,·OH increased with increasing concentration,and the scavenging effect of polyphenols on DPPH·was higher than Vc in rang of 0.1-1.6µg/mL.When the concentration is greater than 0.6µg/mL,the scavenging effects of plyphenols on·OH is higher than Vc.The total reducing ability of polyphenols from PGP improved with the increase of concentration,and when the concentration was 8µg/mL,the total reducing ability was 114 U/mL.

Cavitation Optimization for a Centrifugal Pump Impeller by Using Orthogonal Design of Experiment

Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitation performance. Therefore, it is necessary to find an appropriate solution to improve cavitation performance with acceptable efficiency. In this paper, to improve the cavitation performance of a centrifugal pump with a vaned diffuser, the influence of impeller geometric parameters on the cavitation of the pump is investigated using the orthogonal design of experiment （DOE） based on computational fluid dynamics. The impeller inlet diameter D1, inlet incidence angle Aft, and blade wrap angle ~0 are selected as the main impeller geometric parameters and the orthogonal experiment of L9（3＂3） is performed. Three-dimensional steady simulations for cavitation are conducted by using constant gas mass fraction model with second-order upwind, and the predicated cavitation performance is validated by laboratory experiment. The optimization results are obtained by the range analysis method to improve cavitation performance without obvious decreasing the efficiency of the centrifugal pump. The internal flow of the pump is analyzed in order to identify the flow behavior that can affect cavitation performance. The results show that D1 has the greatest influence on the pump cavitation and the final optimized impeller provides better flow distribution at blade leading edge. The final optimized impeller accomplishes better cavitation and hydraulic performance and the NPSHR decreases by 0.63m compared with the original one. The presented work supplies a feasible route in engineering practice to optimize a centrifugal pump impeller for better cavitation performance.

Determination of Total Flavonoids in Leaves of Paliurus ramosissimus and Orthogonal Experiment Optimization Process

[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.

Orthogonal design of experiment and analysis of abrasive water jet cutting on carbon fiber reinforced composites

The carbon fiber reinforced composite is a new type of composite material with an excellent property in strength and elastic modulus,and has found extensive applications in aerospace,energy,automotive industry and so on.However,this composite has a strict requirement on processing techniques,for example,brittle damage or delamination often exists in conventional processing techniques.Abrasive water jet machining technology is a new type of green machining technique with distinct advantages such as high-energy and thermal distortion free.The use of abrasive water jet technique to process carbon fiber composite materials has become a popular trend since it can significantly improve the processing accuracy and surface quality of carbon fiber composite materials.However,there are too many parameters that affect the quality of an abrasive water jet machining.At present,few studies are carried out on the parameter optimization of such a machining process,which leads to the unstable quality of surface processing.In this paper,orthogonal design of experiment and regression analysis were employed to establish the empirical model between cutting surface roughness and machining process parameters.Then a verified model was used to optimize the machining process parameters for abrasive water jet cutting carbon fiber reinforced composites.

CVD Method for Carbon Nanotubes Preparation Based on Orthogonal Experiment Using C_3H_6

Carbon nanotubes (CNTs) have potential applications in many fields, chemical vapor deposition (CVD) is an effective method for CNTs preparation. By CVD, the catalytic pyrolysis temperature, pyrolysis time and the size of the raw gas flow have a great influence on yield rate of CNTs and their form. In this paper, the orthogonal experiment analysis method is used for studying the influence factors of yield rate of CNTs. Research results show that, in the suitable temperature range of preparing CNTs, there is relatively more CNTs with excellent morphology, otherwise, if the temperature is too low, the growth of CNTs will not be sufficient; if the temperature is too high, then CNTs will be generated with excessive defects; with longer growth time of suitable pyrolysis of CNTs, higher yield of CNTs will be obtained; CNTs morphology with reaction time is not proportional; too low or too high raw gas flow rate is not conducive to the growth of CNTs. We have found the optimum conditions for the CNTs preparation: pyrolysis temperature 68 degrees C, pyrolysis time 35 min, propylene flow rate of 180 mL/min. The results have a reference value for the preparation of CNTS and their composites.

Application of Orthogonal Experiment in EDM Using the Suspended Powder Fluid

To solve the problems of EDM when using the ordinary fluid and mold manufacturing,this paper provides the orthogonal experiment in the suspended powder fluid,which can optimize the main process parameters.And it also achieves the technology of EDM in the suspended powder fluid primarily.

Parameters optimization for direct contact membrane distillation based on orthogonal experiment

Parameter optimization integrating operation parameters and structure parameters for the purpose of high permeate flux,high productivity and low exergy consumption of direct contact membrane distillation (DCMD) process was conducted based on Taguchi experimental design. L16(45) orthogonal experiments were carried out with feed inlet temperature,permeate stream inlet temperature,flow rate,module packing density and length-diameter ratio as optimization parameters and with permeate flux,water productivity per unit volume of module and water production per unit exergy loss separately as optimization objectives. By using range analysis method,the dominance degree of the various influencing factors for the three objectives was analyzed and the optimum condition was obtained for the three objectives separately. Furthermore,the multi-objectives optimization was performed based on a weight grade method. The combined optimum conditions are feed inlet temperature 75℃,packing density 30% ,length-diameter ratio 10,permeate stream inlet temperature 30 ℃ and flow rate 25 L/h,which is in order of their dominance degree,and the validity of the optimization scheme was confirmed.

Optimization of in vitro Regeneration System of Benihoppe Strawberry (Fragaria × ananassa Duch.) with Orthogonal Experiment Design

[Objective] This study aimed to optimize the in vitro regeneration system of Benihoppe strawberry. [Method] Based on orthogonal experiment, the effects of different medium types, plant growth regulator types and concentrations on the regeneration of adventitious shoots of Benihoppe strawberry leaves were in- vestigated. [Result] IBA is an important factor affecting the multiplication of adventitious shoots of Benihoppe strawberry leaves; the optimal induction medium is MS ＋ 2.0 mg/L TDZ ＋ 0.2 mg/L IBA, with an induction rate of 90.00% ; the optimal differentiation medium is MS ＋ 2.0 mg/L 6-BA ＋ 0.2 mg/L IBA, with a differentiation rate of 8.1% ; the optimal multiplication medium is MS ＋ 1.0 mg/L 6-BA ＋ 0.2 mg/L IBA, with an average multiplication rate of each adventi- tious shoot of 7.67 ; the optimal subculture medium is MS ＋ 0.5 mg/L 6-BA ＋ 0. 1 mg/L 2, 4-D, with an average seeding height in each treatment of 5.98 cm; the optimal rooting medium is 1/2MS ＋ O. 5 mg/L 6-BA ＋ 0. 1 mg/L 2, 4-D, with an average number of roots in each treatment of 4.5. [ Conclusion] This stud- y laid the foundation for further investigating the genetic transformation of strawberry and improving the quality of strawberry at the genetic level.

Optimization of Ultrasonic Extraction Process of Total Flavonoids from Mulberry Leaves by Orthogonal Experiment

In this study, by using mulberry leaves as raw materials, ultrasonic extraction process of total flavonoids from mulberry leaves was optimized by orthogonal experiment. Results showed that the maximum yield of total flavonoids （6.1% ） was obtained from mulberry leaves with addition of 45 times the volume of water by ultrasonic extraction at 55 ℃ for three times, 55 min each. According to the verification test, the optimized technical process was reasonable and feasible with high stability.

Optimization of Conditions for Extracting Luteolin from Ternate Grape Fern Herb by an Orthogonal Experiment

[Objectives] This study was conducted to optimize the extraction process of luteolin, a natural product of Ternate Grape Fern Herb, so as to provide a theoretical research basis for the chemical composition, pharmacological research and preparation development of Ternate Grape Fern Herb. [Methods] The effects of four factors including ultrasonic extraction time, liquid-to-material ratio, ultrasonic extraction temperature and ethanol concentration on extraction yield of luteolin from Ternate Grape Fern Herb were investigated by the ultrasonic-assisted extraction technology, through a single-factor experiment and an orthogonal experiment based on the single-factor experiment, and the experimental data was subjected to variance analysis and SSR analysis of the significance of differences between groups by SPSS20.0 software to select the optimal extraction process conditions. [Results] The optimal extraction process conditions were as follows: ultrasonic extraction time 25 min, liquid-to-material ratio 25∶1 ml/g, ethanol volume fraction 60%, ultrasonic extraction temperature 85 ℃. [Conclusions] The results were verified, and it was determined that the ultrasonic-assisted extraction process established in this study is reasonable and reliable, and can be used for the extraction of luteolin.

Simulation analysis of hot dip galvanizing process parameters based on orthogonal experimental design

An iron and steel company＇ s hot galvanizing technology was chosen as the object. An orthogonal experimental scheme with 5 factors of mixed level was designed, according to the various factors affecting the distribution of slag. For each scheme, the amount of slag and slag height in different orthogonal schemes by simulation were obtained with FLUENT software. Then, range and variance analyses were selected to compare the trend of slag height in the different process parameters of the hot dip galvanizing process. Finally, the optimal combination of the process parameters was obtained.

Optimization of Extraction Process for Total Flavonoids from Penthorum chinense Pursh and Comparison of Their Contents from Different Parts

[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh.

Orthogonal Test Design for Optimization of the Extraction of Flavonid from the Fructus Gardeniae

Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae. Methods The key extraction parameters that influenced the yield of flavonid from Fructus Gardeniae were optimized by employing an orthogonal experiment [L9（3）4], including the ratio of buffer solution （Na2B4O7· 10H2O） to raw material, concentration of Fructus Gardeniae in extracting solution, extraction time and pH of buffer solution. An UV/Vis detector was used to perform the qualitative and quantitative analyses of the extracted flavonid with the using of the standard sample. Results The maximum extraction yield of the crude extract was 5.0533 （mg/g） after 20 min when the mass ratio of Na2B4O7 · 10H2O to raw material was 0.4%, the concentration of Fructus Gardeniae in the extraction solution was 1/12 （g/mL）, and pH of buffer solution was 4.5. The positive reactions to the Molish and HCI-Mg tests suggested that the extracted compound was flavonoid, and FTIR measurements also identified the presence of flavonoid in the extracts. Conclusion This work is expected to provide a basis for further research, development, and utilization of Fructus gardenia in flavonid extraction.

Solution for integer linear bilevel programming problems using orthogonal genetic algorithm

An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorithm is developed for solving the binary linear implicit programming problem based on the orthogonal design. The orthogonal design with the factor analysis, an experimental design method is applied to the genetic algorithm to make the algorithm more robust, statistical y sound and quickly convergent. A crossover operator formed by the orthogonal array and the factor analysis is presented. First, this crossover operator can generate a smal but representative sample of points as offspring. After al of the better genes of these offspring are selected, a best combination among these offspring is then generated. The simulation results show the effectiveness of the proposed algorithm.

Control System Development and Experimental Study on Ultrasonic Vibration Feeding

Ultrasonic vibration feeding（UVF） method which can quantitatively feed and precisely deposit fine powder is a potential technique for micro feeding.The excitation sources transmit vibration to capillary though the third medium for most UVF devices.The vibrator is directly touched with the capillary can transmit mechanical energy on the capillary as much as possible,and the powder feeding can be controlled more precise.However,there are few reports about it.A direct UVF system which integrates the function of micro feeding,process observing,and powder forming was developed in this work.In order to analyze the effect of the system factors on feeding,a group of L9（3^3） orthogonal experiments are selected to confirm the effect of level change of factors.The three factors are capillary nozzle diameter,amplitude and signal.The flow rate was stable for each combined factors,and the optimum combination for the minimum flow rate are choosing small capillary,small amplitude,and triangular wave orderly.The whole process of feeding includes start point,middle stage and stop stage.Starting of feeding was synchronized to vibration when the amplitude of capillary nozzle is larger than critical amplitude.Then,the feeding process enters the middle stage,the feeding state is observed by the CCD,and it is very stable in the middle stage.Overflow of feeding can＇t be eliminated during the stop stage.The features of the deposited powder lines are analyzed; the overflow can be diminished by choosing small capillary and appropriate ratio of the capillary nozzle diameter to the particle size.Chinese characters lattices were deposited to validate the ability of quantitatively feeding and fixed feeding of UVF.Diameters of all powder dots show normal distribution,and more than 60% dots are concentrated from 550 μm to 650 μm,and the average diameter for all the dots is 597 μm.Most dots positions are well approached to their scheduled positions,and the maximum deviation is 0.27 mm.The new direct UVF system is used to implement experiments,which confirms the precise controllable of feeding.According improve the feeding technique,it suits well for rapid prototyping,chemistry,pharmaceutics and many other fields,which require precise measurement and feed minim powder.

Orthogonal genetic algorithm for solving quadratic bilevel programming problems

A quadratic bilevel programming problem is transformed into a single level complementarity slackness problem by applying Karush-Kuhn-Tucker（KKT） conditions.To cope with the complementarity constraints,a binary encoding scheme is adopted for KKT multipliers,and then the complementarity slackness problem is simplified to successive quadratic programming problems,which can be solved by many algorithms available.Based on 0-1 binary encoding,an orthogonal genetic algorithm,in which the orthogonal experimental design with both two-level orthogonal array and factor analysis is used as crossover operator,is proposed.Numerical experiments on 10 benchmark examples show that the orthogonal genetic algorithm can find global optimal solutions of quadratic bilevel programming problems with high accuracy in a small number of iterations.

Experiment about Drag Reduction of Bionic Non-smooth Surface in Low Speed Wind Tunnel

The body surface of some organisms has non-smooth structure, which is related to drag reduction in moving fluid. To imitate these structures, models with a non-smooth surface were made. In order to find a relationship between drag reduction and the non-smooth surface, an orthogonal design test was employed in a low speed wind tunnel. Six factors likely to influence drag reduction were considered, and each factor tested at three levels. The six factors were the configuration, diameter/bottom width, height/depth, distribution, the arrangement of the rough structures on the experimental model and the wind speed. It was shown that the non-smooth surface causes drag reduction and the distribution of non-smooth structures on the model, and wind speed, are the predominant factors affecting drag reduction. Using analysis of variance, the optimal combination and levels were obtained, which were a wind speed of 44 m/s, distribution of the non-smooth structure on the tail of the experimental model, the configuration of riblets, diameter/bottom width of i mm, height/depth of 0.5 mm, arranged in a rhombic formation. At the optimal combination mentioned above, the 99% confidence interval for drag reduction was 11.13% to 22.30%.

EXPERIMENTAL STUDY ON UPGRADING OF A FINE-SCALED GRAPHITE ORE BY FLOTATION

Based on the quality and analysis of the medium carbon product whose grade was 81%-82%, the emphasis of the study was placed on the orthogonal experiments of roughing flotation reagent and single factors, such as abrasive grain, pulp concentration and the rotating speed of flotation machine. The result with improvement in the grade of concentrate to 95% through the routine floatation method was achieved.