A fast and accurate solution to optimal design of eddy-current PMCs with standard disc type

Author(s):  
Zheng rong Xia ◽  
Yong chen Pei ◽  
Dong xu Wang ◽  
Shun Wang

Although permanent magnet couplings (PMCs) have been under research for many years and have found successful industrial applications, this is still a technology under development. Accurate parameter determination is of significance for performance analysis and critical decisions on PMC design. However, the determination can often lead to an unacceptable increase in computation, especially when finite elements (FE) are used. The study aims to develop an FE model that is used for the structural design of a standard-disc type PMC for optimal torque. For the quick and accurate design, an integration optimal solution of the response surface methodology (RSM) and the Taguchi’s method was proposed. To verify the simulation, a series of experimental investigations were conducted on a self-developed testing platform. Furthermore, for a minimum set of FE analyses (FEA), a quantitative indicator called contribution rate, which can reflect effect level of structure parameters on the torque, was given based on the Taguchi method. Apart from this, the orthogonal matrix was used for the reduction of the FE calculation. Based on the contribution rate, the response surface methodology was adopted for the optimal torque determination with no increase in the PM volume. According to the optimization results, a fitting formula, which considers the contribution rates of the optimization variables, was presented. The results suggest that the FE simulations agree very well with the experiments, and the fitting formula can be used in the PMC design.

2012 ◽  
Vol 217-219 ◽  
pp. 1567-1570
Author(s):  
A.K.M. Nurul Amin ◽  
Muammer Din Arif ◽  
Syidatul Akma Sulaiman

Chatter is detrimental to turning operations and leads to inferior surface topography, reduced productivity, dimensional accuracy, and shortened tool life. Avoidance of chatter has mostly been through reliance on heuristics such as: limiting material removal rates or selecting low spindle speeds and shallow depth of cuts. But, modern industries demand increased output and not steady operational limits. Various research efforts have therefore focused on developing mathematical models for chatter formation. However, as yet there is no existent model that meets all experimental verification. This research employed a novel technique based on the synergy of statistical modeling and experimental investigations in order to develop an effective empirical mathematical model for chatter amplitude and to subsequently find optimal machining conditions. Ti-6Al-4V, Titanium alloy, was used as the work-piece due to its increased popularity in applications related to aerospace, automotive, nuclear, medical, marine etc. A sequence of 15 experimental runs was conducted based on a small Central Composite Design (CCD) model in Response Surface Methodology (RSM). The primary (independent) parameters were: cutting speed, feed, and depth of cut. The tool overhang was kept constant at 70 mm. An engine lathe (Harrison M390) was employed for turning purposes. The data acquisition system comprised a vibration sensor (accelerometer) and a signal conditioning unit. The resultant vibrations were analyzed using the DASYLab 5.6 software. The best model was found to be quadratic which had a confidence level of 95% (ANOVA) and insignificant Lack of Fit (LOF) in Fit and Summary analyses. Desirability Function (DF) approach predicted minimum vibration amplitude of 0.0276 Volts and overlay plots identified two preferred machining regimes for optimal vibration amplitude.


Author(s):  
Gang Wang ◽  
Rong Wan ◽  
Liuyi Huang ◽  
Fenfang Zhao ◽  
Xinxin Wang ◽  
...  

Abstract In this present work, effects of three Euler angles (Angle of Attack (AOA), Angle of Trim (AOT), Angle of Pitch (AOP)) of vertical cambered otter board on hydrodynamic characteristics (drag coefficient (Cd), lift coefficient (Cl), center-of-pressure coefficients (Cp)) were studied based on numerical simulation combined with Kriging Response Surface Methodology (KRSM) and Multi-Objective Genetic Algorithm (MOGA). Wind tunnel experiments were carried out to validate the accuracy of response surface based on numerical simulation. It was demonstrated that AOA had prominent effects on Cd and Cl, while AOT and AOP had less effects. The working posture of otter board were recommended to lean inwards (0°∼6°) and forward (−10°∼0°) to improve the lift-drag ratio without sacrificing Cl. The influences of AOT and AOP on positions of center-of-pressure point were less significant than that of AOA and decreasing with the increase of AOA. In addition, response surface of hydrodynamic coefficients around the critical AOA was a decent indicator of occurrence of stall. Finally, three candidate cases were selected to satisfy the high working efficiency by MOGA, which was consistent with the above recommendations. This study provided a scientific reference of response surface experimental investigations methodology and the configuration of Euler angles of otter board.


Author(s):  
Indu Bhushan

Lipases are a multipurpose enzyme that holds a significant position in industrial applications due to its ability to catalyse a large number of reactions such as hydrolysis, esterification, interesterification, transesterification which makes it a potential candidate. It is also used for the separation of chiral drugs from the racemic mixture and this property of lipase is considered very important in pharmaceutical industries for the synthesis of enantiopure bioactive molecules. Assuming the tremendous importance of lipases, as stereoselective biocatalysts, in pharmaceuticals and various other commercial applications, industrial enzymologists have been forced to search for those microorganisms which are able to produce novel biocatalysts at reasonably high yield. In the present study microbial lipase was isolated from the water sample of pond at Katra, Jammu and Kashmir (India). This enzyme has shown wide specificity and higher enantioselectivity, which make it pharmaceutical important enzyme. To make it economical for industrial application, it was produced on cheap nutrient media using Response Surface Methodology and got maximum production. It was used for resolution of chiral drugs and the significant results obtained during the course of work shall have potential towards pharmaceutical industries.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1482
Author(s):  
Cassandra Detti ◽  
Luana Beatriz dos Santos Nascimento ◽  
Cecilia Brunetti ◽  
Francesco Ferrini ◽  
Antonella Gori

Pistacia lentiscus leaves are used in several applications, thanks to their polyphenolic abundance. Thiswork aimed to characterize the polyphenols and to optimize the extraction conditions to shorten the time, decrease the consumption of solvent, and to maximize the yield of different classes of phenolics, which have diverse industrial applications. The variables were optimized by applying a Box–Behnken design. Galloyl and myricetin derivatives were the most abundant compounds, and two new tetragalloyl derivatives were identified by LC-MS/MS. According to the models, the maximum yields of polyphenols (51.3 ± 1.8 mg g−1 DW) and tannins (40.2 ± 1.4 mg g−1 DW) were obtained using 0.12 L g−1 of 40% ethanol at 50 °C. The highest content of flavonoids (10.2 ± 0.8 mg g−1 DW) was obtained using 0.13 L g−1 of 50% ethanol at 50 °C, while 0.1 L g−1 of 30% ethanol at 30 °C resulted in higher amounts of myricitrin (2.6 ± 0.19 mg g−1 DW). Our optimized extraction decreased the ethanolic fraction by 25% and halved the time compared to other methods. These conditions can be applied differently to obtain P. lentiscus extracts richer in tannins or flavonoids, which might be employed for various purposes.


2016 ◽  
Vol 79 (1) ◽  
Author(s):  
Abdul Azeez Abdu Aliyu ◽  
Jafri Mohd Rohani ◽  
Ahmad Majdi Abdul Rani ◽  
Hamidon Musa

In recent years, researchers have demonstrated increases interest in studies involving silicon carbide (SiC) materials due to several industrial applications. Extreme hardness and high brittleness properties of SiC make the machining of such material very difficult, time consuming and costly. Electrical discharge machining (EDM) has been regarded as the most viable method for the machining of SiC. The mechanism of EDM process is complex. Researchers have acknowledged a challenge in generating a model that accurately describes the correlation between the input parameters and the responses. This paper reports the study on parametric optimization of siliconized silicon carbide (SiSiC) for the following quality responses; material removal rate (MRR), tool wear ratio (TWR) and surface roughness (Ra). The experiments were planned using Face centered central composite design. The models which related MRR, TWR and Ra with the most significant factors such as discharge current (Ip), pulse-on time (Ton), and servo voltage (Sv) were developed. In order to develop, improve and optimize the models response surface methodology (RSM) was used. Non-linear models were proposed for MRR and Ra while linear model was proposed for TWR. The margin of error between predicted and experimental values of MRR, TWR and Ra are found within 6.7, 5.6 and 2.5% respectively. Thus, the excellent reproducibility of this experimental study is confirmed, and the models developed for MRR, TWR and Ra are justified to be valid by the confirmation tests.


2015 ◽  
Vol 766-767 ◽  
pp. 801-811 ◽  
Author(s):  
S.B. Angadi ◽  
Rashmi Melinamani ◽  
V.N. Gaitonde ◽  
Mrityunjay Doddamani ◽  
S.R. Karnik

In the present paper, the experimental investigations on drilling characteristics of cenosphere reinforced epoxy composites with cemented carbide drill have been presented. The drilling aspects such as thrust and hole surface roughness have been performed as function of four process parameters, namely, spindle speed, feed rate, drill diameter and % weight of the filler. Composite specimens were prepared with 20%, 40% and 60% by weight of cenosphere filler in epoxy resin as the matrix. The full factorial design (FFD) has been employed for conducting drilling experiments and the proposed drilling characteristics were analysed using response surface methodology (RSM) based quadratic models. The response surface analysis reveals that the addition of cenosphere as filler in epoxy resin appreciably decreases with the thrust and hole surface roughness for the developed composites.


2021 ◽  
Vol 67 (3) ◽  
pp. 75-87
Author(s):  
Yong Wang ◽  
Xiaolin Wang ◽  
Zilong Zhang ◽  
Yu Li ◽  
Houlin Liu ◽  
...  

A self-excited pulsed air-water jet (SEPAWJ) offers many advantages over other jets and has a large number of practical and industrial applications. In order to take better advantage of the SEPAWJ, response surface methodology (RSM) models were established with the experimental impact force characteristics as the dependent variable and three key nozzle parameters as the independent variable. Single and coupling factor effects of these three parameters (oscillation chamber length, oscillation chamber height, and diameter of the downstream nozzle) on performance of nozzle are analysed, and the structural parameters of optimum performance are calculated using RSM models. The external flow field, impact force and cleaning performance of SEPAWJ before and after optimization are analysed and compared experimentally. It is found that the significance levels of established average impact force and impact force amplitude RSM models are lower than 0.05, and their error ratios between calculation and experiment under the optimum construction are both less than 5 %, which confirms their considerable reliability. Meanwhile, the final large water mass of optimized SEPAWJ is formed much earlier, and is more intensive and more concentrated. Compared with the original SEPAWJ nozzle, the impact force and impact force amplitude of optimized SEPAWJ nozzle are increased by 52.00 % and 38.26 %, respectively. In addition, the cleaned area ratio of nozzle before and after optimization is 76 % and 100 % at 50 seconds, respectively, with an increase of 22.4 %.


2021 ◽  
Vol 2 ◽  
pp. 26-33
Author(s):  
P. Pondi ◽  
J. Achebo ◽  
A. Ozigagun

Optimization is a very important techniques applied in the manufacturing industry that utilizes mathematical and artificial intelligence methods. The complexity associated with most optimization techniques have resulted to search for new ones. This search has led to the emergence of response surface methodology (RSM). The paper aims to optimize tungsten inert gas process parameters required to eliminate post-weld crack formation and stabilize heat input in mild steel weldment using RSM. The main input variables considered are voltage, current and speed whereas the response parameter is Brinell hardness number (BHN). The statistical design of experiment was done using the central composite design technique. The experiment was implemented 20 times with 5 specimens per experiment. The responses were measured, recorded and optimized using RSM. From the results, it was observed that a voltage of 21.95 V, current of 190.0 A, and welding speed of 5.00 mm/s produced a weld material with the following optimal properties; BHN (200.959 HAZ), heat input (1.69076 kJ/mm), cooling rate (72.07 /s), preheat temperature (150.68 ) and amount of diffusible hydrogen (12.36 mL/100g). The optimal solution was selected by design expert with a desirability value of 95.40 %.


2014 ◽  
Vol 8 (2) ◽  
pp. 166-175
Author(s):  
José A. Díaz-García ◽  
José E. Rodríguez ◽  
Rogelio Ramos-Quiroga

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