Full Factor Experiment Research Articles

ОПТИМІЗАЦІЯ КОНСТРУКЦІЇ ФАКЕЛЬНОГО ЗАПАЛЬНИКА ГТД ЧИСЕЛЬНИМ МЕТОДОМ

Solved the problem of gas-turbine engine combustion chamber flame igniter efficiency increasing by increasing the flame temperature via optimizing the body design. To determine the influence of the igniter body various geometric parameters, affecting the formation and combustion of the fuel-air mixture, a parametric model was developed. This model together with the developed project in the ANSYS Workbench software package made it possible to automate the modeling process. The influence of the geometric parameters of the igniter body and external factors on the average flame temperature has been studied via a numerical model of the stationary combustion process of the air-fuel mixture formed inside the igniter of the combustion chamber of a gas turbine engine by evaporation and spraying particles of aviation kerosene in the air stream. The adequacy of the numerical simulation results was confirmed by the implementation of a series of full-scale experiments using the Fisher criterion.The uniformity of temperature and adequacy of the average temperature estimation algorithm was established using the correlation analysis of the results of measured temperature at various points of the flame. To determine the degree and nature of their influence, sequentially screening (fractional), as well as full-factor experiments with varying factors at two and three levels were implemented. Based on the results of the analysis of variance, the most statistically significant factors were selected. A regression dependence was established that relates the diameter of the air inlet orifice and the air pressure drop to the flame temperature. A qualitative and quantitative assessment of the influence of the considered factors on the process of formation of a hot air mixture and its combustion has been performed. The optimal values of the geometric parameters of the igniter body and its operating conditions are determined under which the maximum flame temperature at the stationary combustion stage is ensured. Relationships between design features, igniter operation mode, and the temperature of the flame are established. This allows expanding the range of stable ignition of gas turbine engine combustion chambers in accordance with the design of the igniter, the starting fuel supply mode, and the air pressure drop.

Effects of operating conditions and pre-densification on the torrefaction products of sorghum straw

The effects of operating conditions and pre-densification on the torrefaction performance parameters and the properties of the torrefied sorghum straw were studied. A full-factor experiment was performed on a fixed tube furnace, in which sorghum straw powder and pellets were heated to 230°C, 260°C, 280°C and 300°C at 2.5°C/min, 5°C/min and 7.5°C/min, respectively. The pyrolysis characteristics of the sorghum straw torrefied under various operating conditions were complemented by thermogravimetric analysis. It was observed that the high temperature led to the high calorific value of the torrefied sorghum straw with an acceptable mass and energy yield. The sorghum straw torrefied at a temperature above 280°C had a higher heating value (HHV) that was comparable to that of the low rank coal while maintaining its energy yield above 85%. The results suggested that temperature was an important factor determining the properties of the torrefied products, and the heating rate would affect the internal temperature of the torrefied biomass by affecting the heat transfer during the torrefaction. The energy densification index of the pellets decreased uniformly as the heating rate increased proportionally, indicating that pre-densification can be used as a potential method to solve the heat transfer delay in the fixed reactors at high heating rates, especially for high temperatures. Keywords: torrefaction, pre-densification, pyrolysis characteristics, operating condition, sorghum straw, heat transfer DOI: 10.25165/j.ijabe.20201304.5517 Citation: Liu X Z, Yao Z L, Cong H B, Zhao L X, Huo L L, Song J C. Effects of operating conditions and pre-densification on the torrefaction products of sorghum straw. Int J Agric & Biol Eng, 2020; 13(4): 219–225.

Research and optimization of the eddy current transducer of dielectric coatings’ thickness on metal surfaces of products

Main purpose of the research is to increase the technical and economic performance of eddy current transducers of the thickness of dielectric coatings.Eddy current method of dielectric coatings’ thickness measurement on metallic surfaces was improved and appropriate measuring instrument was developed. Basic task of eddy current method and eddy current measuring instrument improvement was the accuracy increase of dielectric coatings’ thickness measurement on metallic surfaces and reduction of the influence of external magnetic fields. For this reason, during the process of research relative error of dielectric coatings’ thickness measurement δ was chosen as an optimization criterion. List of pre-potent factors that make significant influence on the accuracy of dielectric coatings’ thickness measurement includes sensor’s oxide core diameter Х1, mm; oxide core’s height Х2, mm; number of turns in the energizing coil Х3, frequency of energizing coil supply voltage Х4, Hz.Mathematical methods of experiment planning theory were used to research eddy current transducers measuring dielectric coatings’ thickness following the task of increasing their technical end economic performance. Among them the cost-optimal planning of the experiment, based on the use of Gray code, and the differential method of determining the primary information parameter.The analysis of different experiment plans showed that the plan built in a traditional way has 26 transitions of different factor levels during the process of its realization, and a plan using Grey code has only 15 transitions. It makes possible to say that the new plan of experiment, built on using Grey code, has optimal number of transitions for mentioned list of factors. It makes this plan optimal taking into account cost and time expenses.Besides, to carry out the traditional plan of experiment, it was necessary to use eight prototype products of eddy current transducers. To perform eight experiments using plan based on Grey code we need only four prototype products of eddy current transducers.Applying full factor experiment, built on using Grey code, mathematical model for eddy current measuring transducers was received with transformed variables.Fulfilled experimental researches allowed to develop a prototype product of eddy current transducer of dielectric coatings’ thickness that provides good accuracy (relative error of thickness is not more than 0.3%) with simple design.

Исследование эффективности обработки деталей при судоремонте с использованием очистки смазочно-охлаждающих жидкостей в магнитном отстойнике

The article considers the problem of cleaning efficiency of cutting fluids used in the technological processes of parts treatment during ship repair. One of the cleaning instruments is a magnetic sump which has a high efficiency at a relatively low cost of operation and maintenance. The laboratory tests of the magnetic sump were carried out using a full-factor experiment, with changing certain parameters in order to identify the coolant purity index when cleaning from mechanical impurities. The dependencies are obtained that connect the value of the coolant purity index with the technological and construction parameters of the magnetic sump. The influence of the coolant purity index in the magnetic sump on the roughness of the polished surface of the samples was revealed. With a decreasing concentration of solids after cleaning in a magnetic sump, the surface roughness parameter of the samples decreases from 0.8 to 0.2 μm. The most rational parameters of the magnetic sump have been determined, at which the optimal surface roughness is observed when processing the engine crankshaft using coolant cleaned in a magnetic sump. The scheme of the experimental facility has been presented to determine the efficiency of cleaning the cutting fluid from the mechanical impurities in a magnetic sump, which includes a LATR adjustment transformer, a 220 / 12V step-down transformer, a voltmeter, an ammeter, a rectifier diode unit, and a magnetic sump. It has been stated that the errors of the presented experimental and calculated dependences did not exceed 10%. It has been inferred that cleaning the cutting fluid in the magnetic sump to maximum values allows increasing the intervals of machine time between cleaning the circle up to 70%.

Research on effect of fiber reinforced composite material's elastic characteristics on strength of rope threaded joint

A series of experiments was conducted in order to investigate the influence of the elastic characteristics of the reinforced composite material on the strength of the detachable rope threaded joint. Since the finite element simulation model of the detachable rope threaded joint was confirmed by an experimental study, it was decided to use it to investigate the influence of the elastic characteristics of the reinforced composite on strength of the presented detachable rope threaded joint. The study is conducted using a simulation model of the threaded joint using a finite element analysis system LS-DYNA. The fibre reinforced material is considered to be a unidirectional orthotropic material, for which according to the calculated by Vereshchaka S. dependencies the greatest influence on the elastic characteristics of which has a parameter ψ1. It is the fiber area ratio in the cross-sectional plane along the longitudinal direction. This parameter is varied within the permitted limits to obtain data on the effect of elastic characteristics on the strength of the threaded joint in the reinforced composite. The basic parameters of the threaded joint are chosen according to a specific scheme, which is suitable for a full factorial experiment according to the classical execution scheme. The construction of the matrix of the full factor experiment is implemented at two levels by three factors. Thus, the type 23 matrix was implemented. The thread depth t is varied within 0.5 ≤ t ≤ 1.0, the thread pitch p – within 1.0 ≤ p ≤ 4.0 and parameter ψ1 - within 0.1 ≤ ψ1 ≤ 0.7. As a result of the study, it has been obtained that the maximum strength is for a threaded joint with the following basic geometric parameters: the thread pitch p = 4 mm, and the thread depth of the profile t = 0.8 mm, the value of the relative volumetric content of the reinforcement in the longitudinal layer direction ψ1 = 0.7. So that the maximum force, which joint can withstand, is up to Rmax = 22.5 kN.

Full factor plan application to polymer composites hardness investigation

Polymer composites have become widespread in many fields of technology. The article considers the creation of a mathematical model for predicting the hardness of dispersed-filled polymer composite materials based on silicone rubbers of synthetic heat resistant low molecular weight rubber A type with fine aluminium hydroxide powder addition. A full factor experiment was chosen as a test method. The main statistical criteria were checked, the reproducibility of the experiments and the adequacy of the obtained model were shown.

SCIENTIFIC SECURITY ASSESSMENT OF SAFETY RISK OF RAW SUGAR PRODUCTS

Proper organization of storage of raw sugar products allows for a long time to maintain product quality and minimize loss of its mass. Difficulties are associated with the high content of free water in them. We have studied the effect of ozone treatment on long-term storage of raw sugar products, including sugar beets. Sugar beet samples were taken from the Koksu sugar factory in the village of Balpyk bi, Almaty region of the Republic of Kazakhstan. The plans for full-factor experiments of the type — 23 out of eight prototypes — were drawn up and each of them was processed with different combinations (max and min) of the following factors: x1 - ozone concentration (g/m3), x2 - processing time (min), x3 - overpressure (ati) (the pressure value can be counted from 0 (absolute pressure) or from atmospheric (overpressure). If the pressure is measured in technical atmospheres, then absolute pressure is denoted as ata, and excess pressure is denoted as ati). Physicobiochemical, microbiological properties, and safety indicators were determined for each sample of sugar beet: mass fraction of moisture, dry matter, acidity, pectin, fiber, sucrose, nitrite, heavy metals, pesticides, mycotoxins, the presence of mold and yeast. As a result of the study, it was found that ozone treatment significantly reduces the growth of mold and yeast, contributes to an increase in the content of pectin, fiber and sucrose, and a safety risk assessment of raw sugar products was scientifically provided.

Analysis of the influence of technological parameters of the chlorogenic acid extraction process from sunflower meal on the degree of its extraction

The object of research is the efficiency of extraction of chlorogenic acid ‑ the natural antioxidant, depending on the conditions of its extraction from sunflower meal. The main problem of this issue is the fact that the extraction degree of the specified phenolic compound is influenced by many factors, such as the degree of grinding of the product, the type of raw material, the method of extraction, the nature of the solvent-extractant, the temperature and duration of the extraction process, the hydromodule in the system «raw – extractant» etc. The impact of each of these parameters requires careful consideration and appropriate research. This will determine the optimal values of the specified parameters of the extraction process and increase the efficiency of extraction of chlorogenic acid.In this work, the raw material for the production of chlorogenic acid is a meal made from sunflower seeds – a cheap second raw material of oil and fat production. Previous studies have found that a high-efficiency extractant of the specified antioxidant is a solution of ethyl alcohol with a concentration of 60 %, and the optimum temperature of the process of extracting chlorogenic acid from sunflower meal is the boiling point of the extractant. As a result of this study, the regularity of the influence on the extraction degree of chlorogenic acid of such technological parameters as the hydromodule in the system «meal ‑ ethyl alcohol solution 60 %» (hereinafter referred to as «meal – extractant») and the duration of the extraction process were studied. Experiments to determine the dependence of the extraction degree of chlorogenic acid on the hydromodule in the system «meal – extractant» and the duration of extraction were carried out in accordance with the plan of the full factor experiment. Mathematical methods using the Microsoft Office Excel 2003 (USA) and Stat Soft Statistica v6.0 (USA) software packages have been applied for experiment planning and data processing.The dependence indicated in the paper is a quadratic function that predicts an increase in chlorogenic acid content during extraction, with an increase in the hydromodule in the «meal‑extractant» system from 1:5 to 1:10 and a decrease in the extraction time from 60 minutes up to 30 minutes. It is established that for the maximum possible increase in the extraction degree of chlorogenic acid from the meal of sunflower seeds, the optimal value of the hydromodule extraction ‑ 1:10, the duration of extraction ‑ 30 minutes. The obtained results allow to increase the extraction degree of chlorogenic acid from sunflower meal from 2.46 % to 5.58 %. This indicates the possibility of increasing the efficiency of extraction of antioxidant more than 2 times.

Development of a Constructive Scheme to Justify the Parameters of a Belt Drive with a Driven Composite Pulley and with Elastic Elements

The article presents a constructive scheme and the principle of operation of the developed belt drive with a composite driven pulley with elastic elements. The technique and electrotsenometric scheme of the experimental setup for changing the loading and driving conditions of the recommended belt drive with composite driven pulleys with a rubber shock absorber are presented. The results of experimental studies on the loading of the shafts and the rotational speed of the transmission pulleys for various rubber grades used in composite pulleys are presented. The results of full-factor experiments to optimize the parameters of a belt drive, as well as the results of production tests of a cleaning machine, in the drive of which the recommended belt drive is used, are presented. Full-factor experiments substantiated the values of the rotational speed of the drum, the tension roller eccentricity and the stiffness coefficient of the elastic element, which provides a high cleaning effect.

Substantiation of Parameters of the Fibrous Material Cleaning Zone

The article provides the scheme and principle of operation of the fiber material cleaning section when using multi-faceted cylinder spikes. Theoretically studied the movement of the fibrous mass on the surface of the edge of the cylinder splitting. The numerical solution of the problem substantiates the main recommended values of the parameters of the fibrous material cleaning zone. Full-factor experiments optimized the necessary system parameters. The article also investigates the influence of the annular cylinder parameters on the cleaning efficiency of the machine based on full factorial experiments. In this case, the following ring cylinder parameters are optimized: the number of revolutions is 455 rpm, the number of faces of the multifaceted spiky is 6, and the gap between the cylinder and the mesh surface is 16 mm.

Processing cottage cheese whey components for functional food production

Introduction. The study offers a new rational approach to processing cottage cheese whey and using it as a highly nutritional functional ingredient in food production. We proposed a scientifically viable method for hydrolyzing cottage cheese whey with enzyme preparations of acid proteases from Aspergillus oryzae with an activity of 400 units/g and a pH range of 3.0 to 5.0.
 Study objects and methods. Pre-concentrated whey was enzymatically hydrolyzed at 30°C, 40°C, and 50°C for 60 to 180 min (pH 4.6). Non-hydrolyzed whey protein concentrates were used as a control. The amount of enzyme preparation was determined by calculation. All hydrolysate samples showed an increase in active acidity compared to the control samples. Further, we conducted a full-factor experiment with three levels of variation. The input parameters included temperature, duration of hydrolysis, and a substrate-enzyme ratio; the output parameters were the degree of hydrolysis and antioxidant capacity.
 Results and discussion. The experiment showed the following optimal parameters for hydrolyzing cottage cheese whey proteins with the enzyme preparation of proteases produced by Aspergillus oryzae: temperature – 46.4°C; duration – 180 min; and the amount of enzyme preparation – 9.5% of the protein content. The antioxidant capacity was 7.51 TE mmol/L and the degree of hydrolysis was 17.96%.
 Conclusion. Due to its proven antioxidant capacity, the whey protein hydrolysate obtained in the study can be used as a functional food ingredient.

Experimental studies results of electromagnetic field effect of dielcometer system to increase the yield of greenhouse crops

The article presents experimental studies of the application of electromagnetic technologies for impact on biological objects. Tomato seeds were chosen as experimental biological objects. For the study, the technological parameters of EMF were obtained using the method of full factor experiment. Laboratory and field studies were carried out. In laboratory studies, the results of EMF effects on chromosomal aberrations of tomato seeds were obtained. Dependencies of chromosomal aberrations in tomato seeds on changes in seeds EMF exposure, EMF frequency, and EMF power flow density were given. In field studies, pre-sowing treatment of tomato seeds with electromagnetic radiation was performed in order to cause changes in biochemical processes in the plant. During the experiment, 55 options of pre-sowing EMF treatment with specified parameters were obtained. Dependencies of tomato seed germination on input parameters - EMF frequency, power flow density and exposure were given. After laboratory and field tests, it was concluded that pre-sowing EMF treatment of tomato seeds with optimal parameters results in an increase in chromosomal aberrations of tomatoes by 5.5%; field germination of tomatoes by 18%.

Biosynthesis lipase from the fungusPenicillium hordeiisolated from waste fat

The article provides a method of isolating a lipase producer and identification methods by classical methods in microbiology of an isolated micromycete producing lipase. The species affiliation ofPenicillium hordeihas been determined. The temperature of micromycete cultivation was studied, as well as the dynamics ofPenicillium hordeilipase biosynthesis. Screening plans were also carried out (Plackett-Berman Plan), then optimization according to the steep climb plan and an experiment based on the plan of a full-factor experiment (three-level CFE) was also conducted to determine the optimal concentrations that are significant for lipase biosynthesis of components. A mathematical model is constructed that describes the relationship between the influence of two significant factors on the volumetric activity ofP. Hordeiculture fluid. The most optimal composition for the culture fluid for lipase biosynthesis,Penicillium hordeimicromycete, was compiled.

DRONE VIDEO CAPTURE – A NEW METHOD IN PRECISION AGRICULTURE

In June 2019, a drone image recording was performed equipped with an RGB camera on an experimental wheat field at an interval of seven days three times a day. Within one day (12.06.2019) information was collected about the weather conditions and eight measurements were made every hour. The commonly accepted indices were calculated: VARIgreen and ExG for the one-month and one-day observations of the received RGB digitized information. A regression model was created for a full factor experiment of type 23. The interaction of the factors that characterize the conditions of the video was evaluated. Conclusions were formulated as to the influence of the factors under which the observations were made. A recommendation was made with regard to which part of the day it is most appropriate to take photos and video surveillance of wheat.

Does ozone treatment of maize seeds influence their germination and growth energy?

This article evaluated the pre-sowing treatment of seeds with electroozonation. A full factor experiment on the influence of the parameters of the technological process of electroozone treatment on the sowing qualities of maize seeds was carried out. Based on the experimental data, the effect of ozone concentration, treatment time and the time before sowing and after treatment on the germination ability, germination energy and growing energy of maize seeds was determined. According to the results of the study, the corresponding regression equations were calculated, graphical dependencies were constructed and method parameters for the pre-sowing treatment of maize seeds with ozone were determined.

Estimation of the influence of the interaction of factors pairs on the coefficient of route execution possibility

Successful execution of a route by a locomotive can depend on the combination of various operational factors. As an indicator that characterizes the reliable operation of locomotives in exploitation, the coefficient of route execution possibility is proposed to use. The task is to get a formula by which it would be possible to obtain the value of the coefficient of route execution possibility with different combinations of factors. As a tool for obtaining an interpolation formula for determining the coefficient of route execution possibility, a full factor experiment was chosen. The calculations of the model coefficients were carried out with a pairwise combination of four factors: the profile of the area, experience of the driver, the length of the shoulder, the weight of the train. The obtained models were checked for adequacy by F-test. On the received models in three-dimensional coordinates surfaces, reflecting the value of the coefficient of route execution possibility in the intervals of factorization, were constructed. An analysis of the obtained surfaces and the distribution of the selected factors by the degree of impact on the coefficient of route execution possibility were carried out.

Результати експериментальних досліджень витрат потужності при перевантаженні телескопічним гвинтовим транспортером сільськогосподарських вантажів

Experimental equipment was developed for conducting research on telescopic screw conveyors, with the help of which a study of this conveyor was carried out according to the developed techniques. To determine the influence of the structural and kinematic parameters of the telescopic screw conveyor on the power consumption of the auger drive during the transportation of corn, wheat and animal feed conducting full-factor experiments. It was determined the amount of power consumption on the auger drive of the telescopic screw conveyor from a change in three main factors: the frequency of rotation of the screw, the length of the elongation of the screw and the angle of inclination of the conveyor. Equations of regression of power consumption are derived depending on changes in the frequency of rotation of the screw, the length of the elongation of the screw, the angle of the conveyor. The results of experimental studies of the amount of power consumption when overloaded with a telescopic screw conveyor showed that the main factors affecting the increase in torque on the drive, the rotational speed of the screw and its elongation length, as well as a combination of these factors.

Prediction model of surface roughness parameters of structural steel created by plasma arc cutting via full factor experiment

AbstractThis article is focused on the prediction model of surface roughness parameters of structural steel created by plasma arc cutting. Optimization of the cutting process is very important from both quality and economy point of view. The presented paper shows the carrying out of the experiment with the specification of the design of experiments method. In these experiments, the influence of three factors ‐ the plasma current, the traverse speed, and plasma gas pressure was observed. Experimental material was selected structural steel S355. Along with the influence of controllable process factors was observed the influence of different plasma gasses. Application of different plasma gas significantly changes surface quality. The result of each experiment series is a regression function that can predict the Rz values according to the process parameters at given intervals. Presented equations can be applied in the production process for adjusting the plasma cutting process in order to achieve required surface quality.

Preparation of triticale flour by ion-ozone treatment for pasta quality improvement

Currently, much attention is paid to the production of organic food. The scientific concept of nanoscience examines the synthesis of an ion-ozone mixture without harmful impurities of nitrogen and carbon oxides in the processing and preservation of food products based on different polarities of electrical current. The negative polarity of the ion-ozone mixture and the positive polarity of the product being processed using cavitation in the electromagnetic field increase the biological and ecological value of the products. Expanding the range of pasta for various categories and segments of the population requires the use of advanced raw materials, which include triticale grain. The method of improving the quality of triticale grain with cavitation and without cavitation on ion-ozone equipment and further processing into flour is proposed. On the basis of full-factor experiments 2 3 and 2 4 , regression equations have been developed that allow comparing the results of ion-ozone treatment with each other and revealing the basic technological properties of triticale of the “Taza” variety. The input variables are parameters of ion-ozone treatment (ion-ozone concentration, humidity before processing and processing time) and ion-ozone-cavitation processing (overpressure, ion-ozone concentration, humidity before processing and processing time). Output variables are: from the indicators of physical properties – density, mass of 1,000 grains; from biochemical properties – mass fraction of protein and content of raw gluten, and macaroni properties – grain hardness and specific work of deformation. This allows evaluating the effectiveness of using it in pasta production. t is proved by experiments that the technological properties of the control and ion-ozone treated samples are significantly different. The proposed technology of ion-ozone cavitation processing of triticale grain at grain-receiving enterprises allows improving physical, biochemical, and pasta properties of flour, which increases the efficiency of pasta production by more than 15 %.

Investigation on thermal damage model of skin tissue in vitro by infrared laser welding

This study aimed to find a parameter that can accurately characterise the thermal damage of skin tissues during laser welding. Combining this parameter with an experiment, we proposed a method to quantify this parameter. A model between laser processing parameters and thermal damage accumulation parameter of skin tissue in vitro was established based on full-factor experiments. The statistical analysis software Minitab was used to design the full-factor experiment. The laser power, spot moving speed, and pulse frequency were taken as independent variables, and the thermal damage parameter of the skin tissue in vitro were taken as dependent variables. A direct correlation model between the thermal damage parameter and the three influencing factors was established, and the laser processing parameters were optimised and verified by experiments. For a laser power of 2.5 W, a spot moving speed of 150 mm s−1, and a pulse frequency of 150 Hz, no irreversible thermal damage occurred in the skin tissue in vitro, and the tensile strength met the requirements. The significant factors influencing the thermal damage of skin tissue in vitro were obtained by conducting a variance analysis, and the related mechanism was analysed.