Part Of Technology Research Articles

What Is the Role of a Systems Engineer In an Engineering Organization?

ABSTRACTThis article discusses the role of a “specialist” Systems Engineer inside an engineering focused on ensures the engineering parts integrate to achieve the objectives of the whole – and so is embedding a systems approach throughout the organization – trying to “make Systems Engineering the way engineering is done”. In this type of organization all engineers need systems engineering as a core skill (which is part of them becoming T‐shaped”. The specialist Systems Engineer needs to be more π‐shaped, with specialism in the systems approach used to inform and guide all the other disciplines which need to be integrated together. Since systems engineering is an integrating discipline the group of systems engineers must not become “just another” technical silo.

Determining the probability of failure of marine diesel engine parts

Maritime transportation is the essence of the international economy. Today, about ninety percent of world trade is carried out by sea through 50,000 merchant ships. Most of these vessels are powered by mainline diesel engines due to their reliability and fuel efficiency. Reliability of system elements in general depends on random failures, significant wear during operation, additional wear during start-up. Accidental damage to diesel engine components is a major hazard during operation, as some parts (such as cylinder liners and pistons) are usually replaced during repairs. On the other hand, preventive service does not eliminate random malfunctions. Therefore, in the general problem of assessing the reliability of a diesel engine, there is a mathematical problem of assessing the reliability and durability, taking into account only the random failures of its elements, which are of the greatest practical importance. The purpose of the work is a mathematical study of the reliability of parts of the cylinder-piston group of the main engines of dry cargo ships. Using a systematic approach and a probabilistic statistical method, it was established that the most common and difficult case is the simultaneous action on a system element (for example, a cylinder sleeve) of factors that cause wear during the period of operation (including during the start-up period) and accidental failures. It was determined that the quality of the cylinder-piston system in ships of the "Ostriv Rosiyskiy" type is higher than in the ships of the "Simferopol" and "Murom" types. Empirical formulas for estimating the probability of emergency failure of main engine system elements during the period of operation between factory repairs were obtained, where the main danger during the period of operation was carried by accidental failures. Based on the results of the study, it is possible to establish a schedule for the periodicity of maintenance of the ship's main engine and the cost of losses due to ship downtime due to failures, and can also be used in the reliability study of other types of ship's main engines. The results make it possible to determine the reliability of the parts of the cylinder-piston group of the main engines of dry cargo ships. and, in particular, to establish the maintenance schedule of the ship's main engine and the cost of damages due to ship downtime due to failures, and can also be used in the study of the reliability of other types of main engines of other series of ships

E-Chem Education

The case for making Electrochemical Science and Engineering part of the core chemical engineering curriculum

Operational Performance of Fish Landing Base (PPI) Lappa Sinjai Regency

This study aims to analyze the level of operational perfomance the fishing port clas PPI Lappa of Sinjai Regency. The research method used in a case study with the aspects studied include the provision of facilities used in PPI Lappa operational activities. Data were analyzed descriptively using the scoring method and operational performance appraisal table. The performance assessment is obtained by comparing the current condition of PPI Lappa with the provisions in the regulations stipulated of The Ministry of Maratime Affairs and Fisheries No. PER.08/MEN/2012 concerning fishing ports and the decision of the Director General of Capture Fisheries No.432/DPT3/0T.220.D3/I/2008 regarding guidelines for evaluating the performance of fishing port technical implementing units. The results of the study show that the performance of coconut PPI Lappa is 63,6 % or good performance status. Each parameter has a high percentage of weight and value success, includes the number of produnction 960,05%, ship visting frequensy 73,3%, ice service 458,10 %, fuel service ships 175,40%, clean water service 22,05% and the availability of port fasilities such as administration office, national marketing, marketing facilities, canteen, and mosque. The facilities available but not functioning are the guard post. Facilities that are not available, such as industrial facilities, processing facilities, ship repair facilities, supply facilities for engine parts and polyclinics.

Performance comparison of rectangular nozzle with circular nozzle of military aircraft engine

Aircraft performance depends on its propulsion system, and the type of exhaust nozzle used in the aircraft plays a major role in jet propulsion. The exhaust nozzle of an aircraft is also the prominent source of infrared (IR) signature from the rear-view, especially in short-wave (1.9–2.9 μm) and mid-wave (3–5 μm) IR bands. Aircraft IR signatures (passive) are used for the detection and tracking by the IR-guided (heat-seeking) missiles. Alterations in engine exhaust geometry are important to reduce the IR emissions from the aircraft’s rear-view. Nozzle shape (e.g., two-dimensional exit, lobed nozzle, S-shaped nozzle) has an important influence on the aircraft and plume IR signature, especially from the rear-view. Rectangular nozzle exit with a high aspect ratio (AR > 5) has an advantage in terms of reduced IR signature, convenience in thrust vectoring, and ease in maneuverability. The wetted perimeter increases with an increase in AR of the rectangular nozzle exit, which results in an increase in the mixing of plume (hot exhaust gases) with the surrounding. This analytical study compares the aero-engine performance and visibility of a rectangular nozzle exit of different AR with that of the circular nozzle. The rectangular exit nozzles of different AR are designed using Solid Edge and their visibility is compared with a circular nozzle of same cross-sectional area, from the direct rear-view. This study shows that the visibility of hot engine parts decreases from the rear and side views with the increase in AR, which is important in reducing aircraft IR-signature. But results in increase in visibility from the bottom view, which is undesirable concerning for the surface to air missiles. The weights of rectangular exit nozzle of different AR are compared with that of the circular nozzle. It is found that the nozzle weight increases with an increase in AR, which increases the aircraft’s lift-induced drag. For performance analysis, the effect on specific thrust is obtained for different nozzle isentropic efficiency. For isentropic flow through nozzle, the results for specific thrust are compared with the values obtained from GasTurb software.

Analisis Perawatan Mesin dengan Menggunakan Metode Reability Centered Maintenance dan Fuzzy Fuzzy Failure Mode and Effect Analysis

In the company there is a problem, namely the high number of downtime that occurs in the SEYI SN-110 Ton press machine at PT. Padma Soode Indonesia. The purpose of this research is to find out the right maintenance action on the system that has been selected using the RCM Reability Centered Maintenance method, to find out which components are prioritized (critical) using Fuzzy FMEA (Failure Mode and Effect Analysis), and provide policy proposals in the form of SOPs. Both methods are types of quantitative methods. The results of data collection are the number of damage to the engine inside that is as much as 40 times in 1 year with a critical percentage of 77%. This has a very big impact on the company where in 1 day the production time / shift is 8 hours, with the downtime level reaching 8 hours which can be said in 1 day there is no production. From the results of data processing using RCM to overcome downtime, namely by doing machine maintenance for 47 days so that there is no more severe downtime later. 47 days to maintain the machine starting from cleaning, replacing components whose economic value is already low and looking at the level of the machine's ability to operate, the results of the research that obtained high critical level components are engine parts with a defuzzication rate of 155. The SOP for machine maintenance uses machine maintenance time from RCM worksheet results.

Діагностика паливної апаратури, приводу клапанів газорозподілу та форсунок змащення циліндрів сучасних двотактних двигунів

The application of a vibration sensor with an in-cylinder pressure sensor extends the capabilities of internal combustion engines and compressor diagnostics for various types of plants and installations, such as marine diesel engines, refrigeration piston compressors, aircraft engines. The fuel injection equipment malfunctions as valve as valve train system malfunctions could be detected from the experimental indicated diagrams P(V), P(deg) of the engine cylinder operating process as it is known. The main indicators are the following: the shape of the diagram and the parameters of working cycle – the maximum combustion pressure Pmax, the compression pressure Pcomp, mean indicated pressure IMEP, etc. However, it should be considered that different types of malfunctions could have the same reflection on the indicated diagram. For instance, the late fuel injection and the fuel-injection equipment wear could have almost similar effects on the indicated diagram and main diagnostic parameters. Another example is the low compression pressure Pcomp, which could be caused by the cylinder or compression rings wear and by the exhaust valves wrong timing or valve leakage. It should also be mentioned that many types of malfunctions at their early stages are very difficult to detect and clarify based solely on the indicated diagrams analysis. The detection of such malfunctions usually requires the direct measurements of the fuel injection pressure and injector’s needle lift diagrams with accurate valve timing measurements. However, mentioned measurements could be performed under laboratory conditions and are difficult to apply under engine operating conditions. The vibration sensor application could be a reasonable alternative to the direct measurements, as it allows the determination of the injector’s needle lift-off and landing timing, high-pressure fuel pump cut-off and discharge timing, the preheated heavy fuel circulation start/stop timing as well as gas-distribution valves opening and closing timing, the oscillation frequency, and amplitude from the refrigeration system piston compressor valve operation and the cylinder oil injector timing. The vibration sensor has a magnetic basement that allows its easy mounting on the engine parts. All this information could be directly measured during engines and compressor trials by the vibration sensor applied in the advanced diagnostic systems.

Оцінка впливу експлуатаційних параметрів на роботу авіаційного газотурбінного двигуна

This paper considers the possibilities of improving the reliability and efficiency of the aircraft engine, which are one of the main indicators of quality and require high-quality fuel. Modern gas turbine engines (GTE) are much more powerful and economical compared with those produced 50 years ago. Nevertheless, manufacturers are constantly working to improve gas turbine engines with the main emphasis on their fuel efficiency. Mechanical impurities present in the fuel can clog the fuel filters, thereby cutting off the fuel supply. The presence of resins in the fuel leads to the formation of various deposits on engine parts, and the content of sulfur, acids and alkalis increases the corrosiveness of the fuel. The completeness of combustion and the tendency of carbon formation are the main performance characteristics of hydrocarbon fuels, which are of great practical importance in improving the efficiency and service life of the engine. Currently, there are many options for improving technical and economic indicators. The proposed ways to prepare a better fuel mixture before supplying it to the engine. The preparation of aviation fuel is carried out because of the electrophysical effects on the fuel. The electrophysical effect on the fuel is determined by a magnetic installation with a sign-changing magnetic field. Studies were conducted to determine the effect of electrophysical impact on the completeness of combustion of aviation fuel and carbon formation in the combustion chamber of a gas turbine engine. The method allows to give a comparative assessment of the completeness of combustion and carbon formation of fuels for engines with a small amount of fuel consumed for testing. It has been established that under electrophysical action on aviation fuel, the fuel combustion efficiency increases by 10...12 %, carbon formation in the gas turbine engine combustion chamber decreases by 20...25 %. The positive effect on the combustion process in the previous phases decreases the afterburning phase, therefore, a decrease in the temperature of the exhaust gases, a decrease in the concentration of nitrogen oxide by 12...16 %, carbon monoxide by 0.64...0.7 % and hydrocarbon by 25...35 %. After the electrophysical impact and the fuel running time, the content of resinous compounds increased four times, the content of oxygen compounds decreased by ~23 %, and the content of sulfur compounds decreased by ~25 %.

A fluid-structure interaction model accounting arterial vessels as a key part of the blood-flow engine for the analysis of cardiovascular diseases

According to the classical Windkessel model, the heart is the only power source for blood flow, while the arterial system is assumed to be an elastic chamber that acts as a channel and buffer for blood circulation. In this paper we show that in addition to the power provided by the heart for blood circulation, strain energy stored in deformed arterial vessels in vivo can be transformed into mechanical work to propel blood flow. A quantitative relationship between the strain energy increment and functional (systolic, diastolic, mean and pulse blood pressure) and structural (stiffness, diameter and wall thickness) parameters of the aorta is described. In addition, details of blood flow across the aorta remain unclear due to changes in functional and other physiological parameters. Based on the arterial strain energy and fluid-structure interaction theory, the relationship between physiological parameters and blood supply to organs was studied, and a corresponding mathematical model was developed. The findings provided a new understanding about blood-flow circulation, that is, cardiac output allows blood to enter the aorta at an initial rate, and then strain energy stored in the elastic arteries pushes blood toward distal organs and tissues. Organ blood supply is a key factor in cardio-cerebrovascular diseases (CCVD), which are caused by changes in blood supply in combination with multiple physiological parameters. Also, some physiological parameters are affected by changes in blood supply, and vice versa. The model can explain the pathophysiological mechanisms of chronic diseases such as CCVD and hypertension among others, and the results are in good agreement with epidemiological studies of CCVD.

Dynamic Investigation and Resonant Frequency Determination of Shaft Bending Fatigue Testing Machine

The testing machine of shaft bending fatigue is widely used to test the fatigue limit and life of various shaft-type parts in mechanical engineering. Machine dynamic characteristics and system bending resonant frequency are very important for the design, testing, and application of the testing machine, but existing complex finite element calculation and aimless large-range frequency scanning in testing are the available methods to solve these two problems helplessly and inefficiently. A novel analytical model of nonlinear coupling dynamic system is built for the fatigue testing machine in this paper. The nonlinear dynamic model is simulated and investigated numerically, then it is reasonably linearized and reduced as a linear one, and the corresponding error analysis and application range are presented. By using eigenvalue approximation, the shaft bending resonant frequency formula is obtained, then the formula is compared and verified with the results from the nonlinear system simulation and finite element software, and it can improve the machine design and testing efficiency obviously. The analytical dynamic modeling and linearizing, and the given mode resonant frequency approximating, also provide a reference for many similar vibration machines.

Strength and Fatigue Life at 625 K of the Ultrafine-Grained Ti-6Al-4V Alloy Produced by Equal-Channel Angular Pressing

Grain reduction in a widely used Ti-6Al-4V alloy increases its endurance limit at room temperature. In this work, the behavior of the ultrafine-grained alloy under cyclic load at the temperature of 625 K is considered. Research was conducted to examine the fatigue life in a low-cycle area of the ultrafine-grained Ti-6Al-4V alloy produced by equal-channel angular pressing. Tensile and fatigue testing of the Ti-6Al-4V samples with coarse-grained (CG) and ultrafine-grained (UFG) structures were carried out at 293 and 625 K. The alloy demonstrated an enhanced strength and fatigue life at both temperatures. The representative features of the microstructural evolution and the fracture features in the UFG and CG alloys after fatigue tests are described in detail. The prospects for the use of the UFG Ti-6Al-4V alloy for engineering applications, such as in the production of critical gas-turbine engine parts, is discussed.

Acoustical engineering: A complete academic undergraduate program in Brazil.

Acoustics is a broad field of knowledge that extends branches all over the physics of wave phenomena, psychology, natural sciences, and engineering. It is taught, in general, as part of engineering, physics, or architecture programs, or even in graduate programs specialized in the theme. In Brazil, acoustics was taught in graduate programs, until the creation of Acoustical Engineering in 2009, at the Federal University of Santa Maria, an integral undergraduate program dedicated to acoustics, audio, and vibration (lasting ten semesters). This article presents its complete academic program, its creation process, and the professional establishment of the acoustical engineer. In the following, the program of study and subjects are elucidated and detailed, and the teaching methodologies used are also discussed. The program employs several active learning strategies, like project-based learning, aiming to transform abstract into concrete knowledge. The interaction of the university, the acoustical engineer, and society is also presented and clarified. The placement of graduates in fields and their workplaces are presented as outcomes. As a fundamental part of the engineer's formation, the infrastructure used, whether state-of-the-art or cost-effective equipment, is detailed in the context of teaching and research. Finally, some of the ongoing research projects of the students are described.

Integrating science, technology, engineering, and math (STEM) and music: Putting the arts in science, technology, engineering, arts, and math (STEAM) through acoustics.

Music is an important part of education and most students are ardent fans. However, the students are not necessarily aware of the artistic and technical details it takes to create what they hear. These details are what necessitate music and technology coming together. Part of science, technology, engineering, and math (STEM) education should be to help students appreciate the practical applications that come from each of the entities in STEM, namely, science, technology, engineering, and math. Music provides the connection of these elements with a topic that interests the students and motivates their learning. This paper outlines ways for educators to integrate music with STEM topics and put the "A" in "STEAM" (science, technology, engineering, arts, and math).

Smart wear sensor device based on nanodiamond multilayers

Diamond coated cobalt-cemented tungsten carbide (WC-Co) cutting tools are widely used for machining light-weight engineering parts made of composite materials. Despite the existence of several methods that can monitor the cutting tools' failure, an earlier prediction only about the coating's wear situation before substrate damage is still missing. In this study, the development of a wear sensor prototype based on a nanocrystalline diamond multilayer system is presented. This multilayer system is built up by two conductive nanocrystalline diamond (CNCD) layers and one non-conductive nanocrystalline diamond (NCD) layer in between. Hot-filament chemical vapor deposition (HFCVD) was utilized as coating process for coating the multilayer system onto WC-Co dummy tools, using a gas mixture of methane and hydrogen. The CNCD's specific conductivity is 10 S/cm, whereas NCD's specific conductivity is 5.4 × 10 −6 S/cm. The impedances of the prototype in the as-grown state and after some wear losses were measured. A linear response of the impedance to the multilayer's wear situation was detected. A theoretical model was established for simulating the sensor principle qualitatively and calculating its sensitivity quantitatively. • A grain boundary dominated electrical conductivity at room temperature was found in undoped nanocrystalline diamond, using Hot-filament CVD for film deposition; • Multilayer sensor system prototype was built up with conductive and non-conductive diamond film layers onto cobalt-cemented tungsten carbide (WC-Co) cutting tools; • A theoretical model and an appropriate detection principle measuring impedance of multilayer's as-grown and wear losses situation were successfully achieved; • The wear situation of a cutting tool can be monitored during machining operation, as to realise an efficient protection of the cutting tools' basic body for possible further reusage.

Crankshaft HCF Research Based on the Simulation of Electromagnetic Induction Quenching Approach and a New Fatigue Damage Model

In recent decades, the electromagnetic induction quenching approach has been widely applied in the surface treatment process of steel engine parts such as crankshafts. In this paper, the strengthening effect of this approach was selected to be the object of study. First, the multi-physics coupling phenomenon was established by a 3D finite element simulation approach. Then, the fatigue property of the crankshaft was predicted based on the combination of the residual stress field obtained in the previous step and a chosen multi-axial fatigue damage model. Finally, a corresponding experiment verification was carried out to check the accuracy of the prediction. The results showed that the method proposed by this paper can provide high enough accuracy in predicting the fatigue property of two types of commonly used steel crankshafts.

Management of Implicit Requirements Data in Large SRS Documents

Implicit Requirements (IMR) identification is part of the Requirements Engineering (RE) phase in Software Engineering during which data is gathered to create SRS (Software Requirements Specifications) documents. As opposed to explicit requirements clearly stated, IMRs constitute subtle data and need to be inferred. Research has shown that IMRs are crucial to the success of software development. Many software systems can encounter failures due to lack of IMR data management. SRS documents are large, often hundreds of pages, due to which manually identifying IMRs by human software engineers is not feasible. Moreover, such data is evergrowing due to the expansion of software systems. It is thus important to address the crucial issue of IMR data management. This article presents a survey on IMRs in SRS documents with the definition and overview of IMR data, detailed taxonomy of IMRs with explanation and examples, practices in managing IMR data, and tools for IMR identification. In addition to reviewing classical and state-of-the-art approaches, we highlight trends and challenges and point out open issues for future research. This survey article is interesting based on data quality, hidden information retrieval, veracity and salience, and knowledge discovery from large textual documents with complex heterogeneous data.

Sequential Reliability Analysis for the Adjusting Mechanism of Tail Nozzle Considering Wear Degradation

The adjusting mechanism is an important part of an aero engine, and the wear degradation of clearance is widely present in its hinges. In this work, an adjusting mechanism with hinge clearance is analyzed by dynamic simulation and the wear depth is predicted precisely using a wear model. Based on that, a sequential reliability analysis of motion accuracy is carried out. In order to avoid the expensive computational cost of simulation, the adaptive radial-based importance sampling method combined with the adaptive Kriging model (AK-ARBIS) is employed, which describes the decrease of reliability in the standard normal space sphere by sphere with the updated Kriging model. To further utilize the information about each state of wear degradation, the advanced AK-ARBIS method is investigated. Through analytical examples of two typical mechanisms and the engineering application of the adjustment mechanism, the results show that the calculation cost of the sequential reliability analysis under different states can be effectively reduced.

Rancang Bangun Alat Uji Momen Inersia Massa Suatu Elemen Mesin dalam Tiga Arah Sumbu

The moment of inertia of the mass is a quantity that is very much needed in designing high-speed engine parts, because it can cause a very large force and the magnitude can be thousands of times its weight. There are two ways to determine the moment of inertia, namely theoretically or testing, if using theory if the shape of machine parts is complicated, of course it is also difficult to determine the magnitude and the second way, namely by testing, it is very easy to get the price of the moment of mass inertia sought even though the shape is complicated. The moment of inertia test equipment is used to determine the value of the moment of inertia of a machine element by means of testing. This tool is also the result of its own design and engineering, which has never been developed by another party. This tool is intended to assists in the Research Development Program in the Department of Machinery, Faculty of Industrial Technology, Jayabaya University. The design of the Test Equipment is based on the Torque Moment principle where the system is considered to have mass and elasticity and from a practical and economical point of view it is very easy to implement. The results of testing the pitch direction and yaw direction with the same test object, namely the connecting rod, it turns out that the test results are Ip = 0.00298 kgm2 and Iy = 0.00304 kgm2 and for testing the direction of rotation using a mass disk of aluminum obtained Ir = 0.00125 kgm2 , the calculation results obtained Ir = 0.1271 kgm2, not too far away or it can be said that the three-axis test equipment, namely the direction of pitch, yaw and rolling can be used for testing the moment of mass inertia for machine elements.

Thermal Barrier Coatings (TBCs) Produced by Air Plasma Spray: Repair by Grinding and Waterjet (WJ) Processes

TBCs (Thermal Barrier Coatings) are multilayer structures usually consisting of a ceramic layer, known as top coat, arranged on a connecting layer, known as bond coat, which, in turn, is arranged above the substrate to protect. These structures are applied in hot section parts of gas turbine engines for providing thermal protection. During the component life, some oxidation end/or wear phenomena can occur, therefore the TBC is generally removed and then reapplied. To simplify the manufacturing process making it more cost effectiveness, the aim of this work is to study the possibility to repair a TBC system by removing the only damaged layer by using non-conventional processes and analyzing in detail the morphological roughness to ensure a good adhesion between the layers.

Study the Biaxial creep of continuous polymer fiber composites

Creep is the slow continuous change in the dimensions of the engineering piece during the service. The study of the creep is one of the very important things in order to avoid the disasters that occur as a result of changing the dimensions. Since we are studying creep and its effect on engineering parts in various fields in which polymer or composite materials are used, and among these areas is the use of polymers and composite materials in dams, then we must choose polymeric materials carefully so that these materials must have special properties in terms of strength and rigidity. In order to meet the required requirements in terms of properties, we chose high-density polyethylene because it has several properties, including its high degree of urgency as well as high inter molecular force, but this material alone does not meet all requirements because the polymer alone is not considered a successful material. High-density carbon fiber and we got a composite material with excellent properties that are much better than high-density polyethylene alone.