Disk Rotation Speed Research Articles

Influence of alumina nanoparticles addition on the tribological behaviour of the random discontinuous carbon fibers reinforced epoxy composites

Discontinuous fibers as reinforcement are a superior choice for polymer composite whenever there is a need to fabricate a complex component or a structure in a mould. Moreover, the effect of alumina nanoparticles (ANP) addition in to polymers has been a popular research topic for the last two decades. The tribological behaviour of polymer composites is one of the essential characteristic that should not be neglected when the material is supposed to face foreign material interaction in its service life. This article thus investigates the wear behaviour of post-cured epoxy-based composites comprising randomly oriented discontinuous carbon fiber (RODCF) with Alumina Nanoparticles (ANP) as filler. Initially, the morphology of the ANP and RODCF was observed using high-resolution transmission electron microscopy (HRTEM) and the scanning electron microscope (SEM), respectively. The experimentation of the tribological analysis was conducted on the pin-on-disc testing apparatus. The load applied to the sample was about 50 N, and the disc's rotational speed was kept at 1000 RPM. The wear test was conducted for 1260 s. It was observed that the inclusion of 2 parts per resin by weight (phr) of ANP in the RODCF/epoxy composite increases the wear resistance of the composite sample considering the existing testing environment, time and material fabrication methodology. Worn-out surface analysis done using the SEM micrograph showed coherence with the pin-on-disc test results. Significant findings of the study are discussed in the article.

Vortex flow affected by disk rotation in an air jet impinging onto a confined heated horizontal disk

An experiment combining flow visualization and temperature measurement is carried out to explore the effects of disk rotation on the vortex flows induced in a round jet of air impinging onto a heated horizontal disk confined in a vertical cylindrical chamber. The experiment is conducted for the jet-disk separation distance at 20.0 mm and 40.0 mm. The jet flow rate is varied from 0 to 5.4 slpm (standard liter per minute) for the jet Reynolds number Rej ranging from 0 to 730. The disk rotation speed varies from 0 to 35.0 rpm for the rotational Reynolds number ranging from 0 to 2725. The temperature difference between the disk and the air injected into the chamber is varied from 0 to 25.0°C for the Rayleigh number ranging from 0 to 150,325. The data from the present study for the ratio of jet disk-disk separation distance to the jet diameter (denoted as HDj) are compared. The results indicate that at the disk rotation rate Ω ≥ 10.0 rpm the secondary inertia-driven roll is completely wiped out for HDj = 4. For HDj = 2 at a higher disk rotation rate of Ω ≥ 20.0 rpm, the buoyancy-driven roll can be substantially squeezed by the disk rotation to become smaller and weaker. Meanwhile, the primary inertia-driven roll is stretched out to become slender and weaker. But for HDj = 4, due to a stronger buoyancy-driven vortex flow at a higher jet-disk separation distance, a higher Ω is needed to stabilize the buoyancy-driven roll.

Highly efficient azo dye degradation in a photocatalytic rotating disc reactor with deposited l-histidine-TiO2-CdS

In the past few years, the quest for visible light active TiO2-based photocatalysts has been a hotly debated research topic in both scientific and practical fields. Attempting to meet the same purpose, in this study, a visible-driven nanocomposite, l-Histidine (2 wt%)-TiO2-CdS (7:1) nanocomposite, was dip-coated on the glass disc (rough vs. smooth) after the optimum composition was identified by varying the l-Histidine and CdS quantities. The prepared nanoparticles and coated catalyst on the disc were characterized by XRD, FT-IR, X-ray (FE-SEM/EDX), DRS, PL analyses in terms of their structural and optical properties as well as morphology. The coated photocatalyst was tested for photocatalytic degradation of direct red 16 (DR16) as an azo dye. The photodegradation process variables, including disc rotation speed, light intensity, irradiation time, and type of disc (smooth vs. rough glass disc)) were also modeled and optimized by central composite design (CCD). At the optimum conditions obtained, the effects of reaction time, pH, DR16 concentration, and aeration were investigated. After 3 h of using the rough disc (disc II) at a disc rotation speed of 100 rpm as well as a light intensity of 13 lumens per m2, DR16 was completely degraded. The pH and DR16 concentration seemed to have the reverse impact on the photodegradation process, whereas aeration had such a positive effect. By analyzing the effects of various scavengers, the contribution of reactive species in the photodegradation process was thoroughly investigated. Furthermore, the reusability results indicate no significant change in the photodegradation efficiency after four cycles.

Eigenfrequencies of rotating discs in dense fluid: imposed modal motion approach

The mode split on disc like structures rotating in a dense fluid leads to a deviation of eigenfrequencies at high rotational speeds compared to their values in still water. Predicting eigenfrequencies correctly is essential to avoid fatigue cracks on prototype turbine runners. Analytical models for simple geometric configurations and complex numerical models using fully coupled fluid structure interaction to predict the mode split on arbitrary geometries exist. We are presenting a complementary approach of intermediate complexity applicable to arbitrary geometries. Mode shapes and modal parameters are computed by finite element analysis in still water. These mode shapes are imposed with a harmonic variation in time during an unsteady computational fluid dynamics computation. From the interaction between the flow and the modal motion, the modal force and the modal work can be computed. These can be converted into added modal mass and hydrodynamic damping and further into the shift of the eigenfrequency under rotation due to the fluid for a given mode. The tendencies of the frequencies with rotation compare reasonably well with experimental data. The numerical method can be applied to disc rotation speeds far beyond the range of experimental data revealing interesting tendencies and a phenomenological interpretation of the cause of the mode split.

Clearance flow patterns and pressure distribution of a pump-turbine: Measurement and simulation of a rotating disk flow

The clearance flow patterns and pressure distribution determine the clearance axial hydraulic thrust of a pump turbine, which has a substantial impact on the unit axial imbalance. However, due to the tiny size and complex shape of the clearance flow channel, there is no detailed description of the flow patterns and pressure characteristics. In this study, we conducted a model test with particle image velocimetry (PIV) measurements and CFD simulation of a rotating disk flow that was a simplified model of the pump-turbine clearance flow. It is shown that a typical Batchelor flow is formed in the clearance region, demonstrating a “core region + double-boundary layers” distribution for the circumferential velocity along the clearance height direction; the core region rotates at a speed of only around 41–42% of the rotating disk speed and is independent of the clearance inlet pressure and clearance height. Driven by centrifugal force, the flow is radially outward around the rotating disk, while inward around the stationary disk in the meridian section, showing secondary flow vortices. The pressure in the clearance region has a circumferentially symmetric and radially quadratic distribution. Based on the liquid differential equilibrium equation and core region circumferential velocity, the pressure and clearance axial hydraulic thrust in the clearance region can be expressed as a function of the clearance inlet pressure and the square of the runner rotating speed. These findings can be used to investigate axial force imbalance issues of the pump-turbine unit.

SVM and ANN Modelling Approach for the Optimization of Membrane Permeability of a Membrane Rotating Biological Contactor for Wastewater Treatment.

Membrane fouling significantly hinders the widespread application of membrane technology. In the current study, a support vector machine (SVM) and artificial neural networks (ANN) modelling approach was adopted to optimize the membrane permeability in a novel membrane rotating biological contactor (MRBC). The MRBC utilizes the disk rotation mechanism to generate a shear rate at the membrane surface to scour off the foulants. The effect of operational parameters (disk rotational speed, hydraulic retention time (HRT), and sludge retention time (SRT)) was studied on the membrane permeability. ANN and SVM are machine learning algorithms that aim to predict the model based on the trained data sets. The implementation and efficacy of machine learning and statistical approaches have been demonstrated through real-time experimental results. Feed-forward ANN with the back-propagation algorithm and SVN regression models for various kernel functions were trained to augment the membrane permeability. An overall comparison of predictive models for the test data sets reveals the model’s significance. ANN modelling with 13 hidden layers gives the highest R2 value of >0.99, and the SVM model with the Bayesian optimizer approach results in R2 values higher than 0.99. The MRBC is a promising substitute for traditional suspended growth processes, which aligns with the stipulations of ecological evolution and environmentally friendly treatment.

New insight into hydrodynamic and cake erosion mechanism during rotating-disk dynamic microfiltration of concentrated bentonite suspensions at different salinity conditions

The present study investigates the dynamic filtration of concentrated slurry fluids containing colloidal clay particles under different salinity, shear flow, and flux rate conditions. The dynamic filtration study was carried out by the filtration cell equipped with a rotating disk to apply shear stress over the membrane surface. A 3D CFD simulation has been implemented to model the hydrodynamic flows inside the filtration cell to obtain the wall shear stress (WSS) on the membrane surface at different disk rotation speeds. The thickness and surface patterns of fouling were captured utilizing a surface profilometer. First, the cake-filtration model was used to predict the flux rate and fouling thickness under static filtration. Then, the corresponding filtrate flux at stabilized cake thickness under shear flow conditions was calculated. The results showed that increasing the suspension salinity causes the reduction of rheological properties and increases the cake permeability due to the compression of the electrical double layer around clay particles. The results also revealed that increasing the flux rate condenses the cake and reduces erosion. Finally, a model for predicting the rate of fouling removal during dynamic filtration was developed using nonlinear regression. The results showed that a sigmoidal function with appropriate accuracy (R2>0.96) could describe fouling thickness patterns with WSS. Moreover, the mean cake thickness decreased by 80% as the WSS increased from 0 to 2 Pa, where the rotating disk speed increased from 0 to 500 rpm.

Hydrodynamic Analysis of the Thickness Variation in a Solid Film Formed by a Spin Coating Process

The surface profile of the film formed by spin coating is experimentally investigated in this paper. The unavoidable wavy form at the surface was observed when the ultraviolet curable resin was used. In addition, the surface thickness variation was directly related to the viscosity, disk rotation speed, and disk size. Fluid dynamic theory with non-dimensional analysis was conducted to describe the surface profile after the spin coating process. It was found that the film had been thickened until the viscosity force and Coriolis force were balanced. The Coriolis force, however, also affected the flow instability during the spinning of the disk. The film thickness variation is successfully described by using the non-dimensional factors. In addition, the edge bump which is induced by hydraulic jump is expressed by the relation of power law of Ekman, Weber, and Reynolds numbers. In this paper, the thickness variation and edge bump position are expressed by using hydrodynamic theory. It is also reveals that the Coriolis force acts based on the magnitude of thickness variation, and the surface tension affects the edge bump position. The presented relationships will contribute further understanding of the spin coating process. The outcome of this paper supports the cost-effective productions of electronic microcircuits and solar cells.

Effect of Operating Parameters and Energy Expenditure on the Biological Performance of Rotating Biological Contactor for Wastewater Treatment

The rotating biological contactor (RBC) is resistant to toxic chemical and shock loadings, and this results in significant organic and nutrient removal efficiencies. The RBC system offers a low-energy footprint and saves up to 90% in energy costs. Due to the system’s low-energy demand, it is easily operable with renewable energy sources, either solar or wind power. An RBC was employed to degrade pollutants in domestic wastewater through biodegradation mechanisms in this study. The high microbial population in the RBC bioreactor produced excellent biological treatment capacity and higher effluent quality. The results showed that the RBC bioreactor achieved an average removal efficiency of 73.9% of chemical oxygen demand (COD), 38.3% of total nitrogen (TN), 95.6% of ammonium, and 78.9% of turbidity. Investigation of operational parameters, disk rotational speed, HRT, and SRT, showed the biological performance impact. Disk rotational speed showed uniform effluent quality at 30–40 rpm, while higher values of disk rotational speed (>40 rpm) resulted in lower effluent quality in COD, TN, and turbidity. The longer hydraulic retention time and sludge retention time (SRT) facilitated higher biological performance efficiency. The longer SRTs enabled the higher TN removal efficiency because of the higher quantity of microbial biomass retention. The longer SRT also resulted in efficient sludge-settling properties and reduced volume of sludge production. The energy evaluation of the RBC bioreactor showed that it consumed only 0.14 kWh/m3, which is significantly lower than the conventional treatment methods; therefore, it is easily operable with renewable energy sources. The RBC is promising substitute for traditional suspended growth processes as higher microbial activity, lower operational and maintenance costs, and lower carbon foot print enhanced the biological performance, which aligns with the stipulations of ecological evolution and environment-friendly treatment.

Citric acid production using rotating biodisc reactor (RBR)

Citric acid is one of the most remarkable industrial goods fabricated by industrial fermentation using filamentous fungus. When Aspergillus niger, a filamentous fungus, is produced under suitable conditions, high amounts of citric acid are obtained. This study aims to explain the citric acid synthesis studied in a biodisc reactor using A. niger. Various physiological parameters have been investigated in order to determine the optimum citric acid synthesis in biodisc reactor. Optimum incubation time was found to be as 168 hours in the study. The optimum value of the incubation temperature was determined to be 30°C. The optimum value of the initial pH was found to be 3.8. Optimum citric acid synthesis occurred when the disc rotation speed was 2 rpm. In addition, the optimum value of the initial sugar (sucrose) concentration was determined to be 20%. In a semi-continuous production study with the renewal of the medium after a certain incubation period, it was determined that the citric acid yield increased approximately 3 times compared to the batch system. As a result, the highest value of citric acid was determined as 67.65 g/L.

转勺式水稻精量穴直播排种器设计与试验

In order to realize the mechanical direct seeding of precision rows and hills in rice field, a rotary precision hill direct seed-metering device for rice was designed. Through designing the key components of seed-metering device and analyzing its working principle, the main factors and critical conditions affecting the seed-metering performance were obtained. Using the secondary rotation combination test, taking the rotation speed of seed-metering disc and seed capacity height as the test factors, and the re-broadcasting rate, seed-metering qualified rate and miss-seeding rate as the indexes, the seed-metering performance was experimentally studied by using the JPS-12 seed-metering device tested. Design-Expert 6 0.10 software was used to analyze the test data to obtain the mathematical model between factors and indexes. The test results show that when the speed of the seed-metering plate was 24.60 r/min and the seed capacity height was the radius of the seed-metering disc, the qualified rate of seed-metering was 94.83%, the re-broadcasting rate was 3.43%, and the miss-seeding rate was 1.74%. The seeding performance meets the agronomic requirements of rice seeding, and provides a reference for the design of the whole machine.

MODERNIZATION OF CORN GRAIN CRUSHER IN THE CONDITIONS OF IT-SYSTEM EQUIPMENT

Corn is widely used as a source of starch in the food, pharmaceutical, paper, mining and construction industries.This starch is usually obtained after the cleaning process, and corn germ, fiber and protein are also produced. It is used in theproduction of biodegradable plastic bags, medicines, paper, corrugated cardboard, detergents, paints, diapers, cosmetics,glue, surfactants and agrochemicals. Corn is the most important grain in the world. After all, in addition to the highest consumptionof all grains, corn is also a universal product from which you can get fuel, electricity and household goods. Thismeans that by increasing the volume of corn processing, it is possible to go beyond the agricultural sector and create goodswith high added value. Growing corn for grain allows better use of agricultural machinery due to the later dates of sowingand harvesting. Valuable properties of corn cause its consistently high demand on the world market.Corn grain processing is part of the technological lines that are part of cereals. The main equipment that ensureshigh quality products are impact centrifugal crushers.Analysis of the operation of the impact-centrifugal crusher revealed the possibility of its operation in a wide range ofchanges in design parameters. The oretical aspects of the dependences of crusher productivity, which basically take its designparameters and modes, include: rotational speed of grinding discs, disc diameter, disc tooth length, thickness, and propertiesand parameters of grain material.As a result of the conducted researches the possibility of increase of qualitative characteristics of the processedproducts, and also productivity of the shock-centrifugal crusher is defined.To increase productivity, it is proposed to implement two options. On the one hand to make the rotational speed ofthe adjustable working body, on the other hand to increase the sizes of diameters of working disks, taking into account a designof the crusher for corn grain, having provided productivity of the crusher.The purpose of this work is to increase the efficiency of the grain crusher, which is part of the preparation of grainfor grinding, to ensure the reliability of the machine, its productivity, improve the quality of finished products by implementingautomation based on SMART-technology, defined as self-control technology and reporting. This technology provideslong-term archiving of the received data that allows the dispatcher to watch work of the corresponding equipment, reactingby means of the IT- service program.

Response Surface Methodology and Artificial Neural Network Modelling of Membrane Rotating Biological Contactors for Wastewater Treatment.

Membrane fouling is a major hindrance to widespread wastewater treatment applications. This study optimizes operating parameters in membrane rotating biological contactors (MRBC) for maximized membrane fouling through Response Surface Methodology (RSM) and an Artificial Neural Network (ANN). MRBC is an integrated system, embracing membrane filtration and conventional rotating biological contactor in one individual bioreactor. The filtration performance was optimized by exploiting the three parameters of disk rotational speed, membrane-to-disk gap, and organic loading rate. The results showed that both the RSM and ANN models were in good agreement with the experimental data and the modelled equation. The overall R2 value was 0.9982 for the proposed network using ANN, higher than the RSM value (0.9762). The RSM model demonstrated the optimum operating parameter values of a 44 rpm disk rotational speed, a 1.07 membrane-to-disk gap, and a 10.2 g COD/m2 d organic loading rate. The optimization of process parameters can eliminate unnecessary steps and automate steps in the process to save time, reduce errors and avoid duplicate work. This work demonstrates the effective use of statistical modeling to enhance MRBC system performance to obtain a sustainable and energy-efficient treatment process to prevent human health and the environment.

Vegetable Oil Based Compressor Oil-optimising of Tribological Characteristics

ABSTRACT This study explored the use of vegetable oil-based polyolester of rapeseed oil as a potential biolubricant for reciprocating air compressor. Rapeseed oil-based pentaerythritol ester (PE) was formulated via ultrasound-assisted transesterification process. Response surface methodology (RSM) based D-optimal design of experiments was used to analyse the tribological parameters, such as disc rotational speed, load and compressor oils on various tribological behaviours, namely, coefficient of friction (COF) and specific wear rate (SWR) using a pin-on-disc tribometer. The least specific wear rate of 1.85 × 10−5 mm3/Nmand COF of 0.0393 was recorded at optimal conditions. The surface morphology analysis of the tested pin using SEM/EDX and tribo-film formation analysis of disc surface using XPS technique disclosed that blended compressor oil (PE75), i.e., 75% by volume of PE and 25% by volume of synthetic compressor oil (SAE30) has numerous capabilities as environmental friendly compressor oil.

Performance evaluation and multi-response hybrid optimization of grinding assisted rotary disk ECDM during cutting of Al-6063 SiCp MMC

The Metal Matrix Composites (MMCs) are being used in many applications, including aerospace, shipbuilding, anddefence industries owing to their high strength to weight ratio. However, the machining of these materials is stillchallenging, necessitating advanced machining techniques. The current investigation aimed to analyze the performance ofthe grinding-assisted rotary disc-electrochemical discharge machining (GA-RD-ECDM) process during cutting Al-6063SiCp MMC. Detailed experimentation was performed to study the energy interaction behavior and effect of input processvariables viz. applied voltage, pulse on time, electrolyte concentration, and disc rotation speed on performance measures.The responses selected were taper, overcut (WOC), and Materials Removal Rate (MRR). The experimentation work wasperformed by adopting response surface methodology. Regression models were developed and statistically analyzed throughanalysis of variance (ANOVA). Eventually, the GA-RD-ECDM process was optimized using the VIKOR methodology ofmulti-criteria decision-making by considering accuracy and productivity simultaneously to obtain minimum taper and WOCand maximum MRR. The results of ANOVA revealed that input variables were statistically significant. Applied voltagemost significantly affects the performance of the GA-RD-ECDM process performance. The optimal values of input processvariables obtained by VIKOR method were applied voltage = 100 V, pulse-on time = 3 ms, Electrolyte concentration = 18%wt/vol. and disc rotation speed = 30 rpm. The present work can provide a productive solution for cutting of difficult-to-cutmaterials. Thus, in future, the GA-RD-ECDM process can be investigated for other advanced materials (i.e., glass, polymercomposites and ceramics) for fabrication of microchannels for microfluidic applications.

Investigation on the Electrical and Rheological Properties of AlN-Based Synthetic Ester Nanofluids

The present study deals with the characterization of electrical and rheological behaviour of the Synthetic ester fluid incorporated with various concentration of Aluminium nitride (AlN) nanoparticles. Zeta potential measurement has shown an excellent stability of the ester fluid mixed with the nanoparticle. Corona inception voltage (CIV) measured using ultra-high frequency (UHF) technique and the results confirmed higher discharge resistance for nanofluid dispersed with 0.005% of AlN. Phase resolved partial discharge (PRPD) analysis with higher harmonic voltages has shown increase in pulse magnitude and number of discharges. Dielectric constant and tan <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\delta $ </tex-math></inline-formula> measurements have revealed a slight marginal increase in its value with the inclusion of filler. Streaming current magnitude was found to increase with the disc rotational speed, concentration of nanoparticle and ambient temperature. Fluorescence spectroscopy analysis has shown increase in fluorophores intensity with filler dispersion in the ester fluid. Rheological properties of fluids mixed with nanoparticles are inspected with cone plane geometry configuration. Synthetic ester and its nanofluid exhibited Newtonian behavior of flow pattern and are independent of the applied shear rate. An exponential decay of viscosity of nanofluids was observed with temperature and it follows an Arrhenius law. The calculated activation energy has increased with the incorporation of filler concentrations. The complex modulus of AlN nanofluids was observed alongside exhibiting the viscous behavior where the loss modulus <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{G}''$ </tex-math></inline-formula> is much larger than the storage modulus <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{G}'$ </tex-math></inline-formula> , with the applied frequency.

Results of laboratory and bench-scale studies of seed dispensers with an electric drive of working tools

Mechanical and pneumatic seed drills of both domestic and foreign production are used in Russian farms. They are equipped with a mechanical drive of working tools and an electronic seeding control system. Due to the slipping of the wheels or the breakage of the chains, the sowing of seeds in individual seed dispensers interrupts. According to the results of laboratory and bench-scale studies in respect to soybean seeds, the required power for the electric drive of one seed dispenser was determined, which, depending on the disk rotation speed from 10 to 60 rpm, ranged from 30 to 120 W. By calculation, using the analytical expression, the power, required for the fan drive of a 12-row seed drill, was determined, which, depending on the disk rotation speed, ranged from 1.6 to 2.47 kW. A condition is formulated, which will eliminate the probability of shifting and rolling seeds along the furrow after their fall out of the sowing disc rotating in the opposite direction to the movement of the seeder unit, provided correspondence of the linear speed of the sowing disc and the speed of the seeder unit (the effect of zero overlaps). In this case, the trajectory length of the seeds falling to the furrow should be consistent with the speed of the seeder unit and the seeding rate according to the proposed expression.

Study on magnetic preparation of dual disk based on silica gel magneto-elastic abrasive particles

Magneto-elastic abrasive grains have magnetism, low elastic modulus and excellent abrasive performance, and have the characteristics of bonded abrasive grains and loose abrasive grains. The dual-disk magnetic preparation greatly improves the preparation quality and efficiency. Firstly, the magneto-elastic abrasive particles are introduced into the edge preparation of the dual-disk magnetic tool, and the preparation method of 4035 silica gel magneto-elastic abrasive particles is proposed. According to the microscopic characteristics of the magneto-elastic abrasive particles, the finite element software ABAQUS is used to establish the magneto-elastic abrasive particles. The meso-level representative volume element (RVE) model is built to analyze the stress and strain law of magneto-elastic abrasive particles under tension and compression. Secondly, an experimental platform for magnetic preparation of magneto-elastic abrasive particles with dual disks was built to analyze the force of magneto-elastic abrasive particles. Finally, Through the magnetic preparation experiment of the magneto-elastic abrasive dual-disk magnetic force, the influence of the disk rotation speed, abrasive particle size and relative magnetic permeability on the cutting edge wear is studied. And compared to the magnetic abrasive particles double-disk magnetic and drag finishing method, the magneto-elastic abrasive particle double-disk magnetic preparation method can obtain the maximum edge wear amount and the maximum surface roughness decreasing amplitude. The research results are of great significance to promote the progress of our country's magnetic high-efficiency processing and magneto-finishing processing technology.

Study on the process of droplet formation when liquid flows out of a capillary

This article presents the theoretical background for the justification of the parameters of the rotating sprayer. Theoretical studies show that an increase in the rotation frequency of the disk at a constant air flow velocity leads to a minimum median mass diameter of the droplets. Therefore, when justifying the diameter of the sprayed droplets, it is necessary to consider the combination of the disk rotation speed and the axial velocity of the air flow. To obtain high-quality air-droplet flow, the initial speed of the main droplets discharged from the periphery of the spray disc should be less than the air velocity and rotational frequency Pavlovskyi spray is recommended to be applied with in ω=60… 200 c1.

Multitarget optimization method for full-aperture lapping process using temperature-controlled lapping disc

Process parameter optimization is important for improving the lapping effect of optical elements. Based on a temperature-controlled lapping disc, we present a method using fuzzy theory and orthogonal experiment to optimize lapping process parameters. Unlike the theory of optimization target set with a single evaluation criterion, a comprehensive optimization target with multiple evaluation criteria based on a fuzzy algorithm is proposed in this method. The lapping disc temperature, lapping disc rotation speed, and lapping pressure were selected as the optimization process parameters, and the material removal rate (MRR), surface change uniformity (SCU), and fuzzy synthetic index of lapping (FSILAP) were used as the optimization targets to conduct comparative experiments and analysis. The experimental results showed that when using the optimal process parameter combination obtained by the comprehensive index FSILAP as the optimization target, balanced results for MRR and SCU could be obtained. Notably, the result obtained when using a single evaluation criterion as the optimization target was suboptimal. The proposed method is effective and practical for the optimization of lapping process parameters.