rss_2.0Engineering FeedSciendo RSS Feed for Engineering Feed Functions of VSC Based HVDC Transmission Systems that Can Effectively Support the Future South-East European Grid with Low Inertia and Large Amount of Res Generation<abstract> <title style='display:none'>Abstract</title> <p>The energy mix in South-East Europe is nowadays mainly composed by hydro and fossil fuels generation almost equally distributed in the share of electricity generation. Wind and solar PV generation play a very marginal role playing cumulatively less than 7% of the total generation, while fossil fuels exceed 52% of the total generation. A Multi-Terminal HVDC grid between the different countries in South-East Europe may provide various operational and socio-economic gains. In this paper are presented some grid specific challenges and explored some new functions of HVDC transmission systems based on VSC technology that can effectively support the grid with large amount of RES. The paper aims to explore how the VSC converters can improve the system’s voltage stability and provide the necessary frequency control when the inertia in the grid is very low and how the HVDC transmission system can accomplish transferring the primary and secondary reserves solving the rising problems related to dispatchability and inertia response in RES based power grids.</p> </abstract>ARTICLEtrue Transformation Path of Manually Collected Meter Reading Data<abstract> <title style='display:none'>Abstract</title> <p>The global trend of digital transformation is not reserved for those sectors and businesses that are highly dependent on information technology (IT) solutions, but even for those traditional energy companies that still need to pass the long way to maximize green energy, automation and full trajectory of modernizing energy distribution. In energy distribution system Public Enterprise Electric Utility of Bosnia and Herzegovina (PE EP B&amp;H), only around sixteen percent of meters are part of Advanced Metering Management (AMM) system and their data is ready to be used for different data analysis using business intelligence, while data collection from other meters is still done manually, and those one will probably not be replaced as long as they are operable. Main problem that PE EP B&amp;H experienced in digitalization of meter reading data was to overcome readings that meter readers collected and wrote on paper lists.</p> </abstract>ARTICLEtrue Pulse Combustor for Enhancing Efficiency and Sustainability of Fossil Energy Conversion<abstract> <title style='display:none'>Abstract</title> <p>The paper actualizes earlier research in developing a pulse combustion technique for enhancing the efficacy of utility and industrial boilers and furnaces. Some unpublished results of the experimental investigation of self-sustained pulsating combustion of a gas fuel in an aerovalved pulse combustor (PC) are presented. Relationships have been established between all important design and operating parameters and the combustion characteristics. It was demonstrated that a well-designed pulse combustor can operate efficiently in a stable self-pumping regime in a wide range of operating conditions with the loading from 20% to 100% of the maximum power. While a PC can operate autonomously as a gas burner, the present focus is on their use for mitigating slug and ash deposits on heating surfaces of coal- or biomass fired power and industrial boilers, thus providing an alternative to the proven detonation pulse (DPC) or other techniques for on-line cleaning of heating surfaces during the operation of power and industrial boilers.</p> </abstract>ARTICLEtrue in BiH<abstract> <title style='display:none'>Abstract</title> <p>In this paper an overview of the current state of electromobility in Bosnia and Herzegovina (BiH) and a prediction of the future state of electromobility in BiH according to models from the European Union (EU) and the state expected in the future is given. Based on the reference state, an analysis of energy consumption and energy savings due to the increase in the number of EVs in the future was performed. The main goal of this paper is to provide predictable data on the number of EVs expected in the future, according to models from the EU. These data can be used when planning the development of the network for electric cars, mainly charging stations. An analysis of the current state of the number and locations of charging stations for electric vehicles (EVs) was made.</p> </abstract>ARTICLEtrue of Failure States of Functional Systems of Aircraft Such as Boeing 737 in the Airline<abstract> <title style='display:none'>Abstract</title> <p>The article presents the results of analysis of failures of the main functional systems units of aircraft Boeing 737 during the last 10 years of its operation in the national airline of Latvia ‘Air Baltic Corporation’. Total flight time was T<sub>∑</sub> = 322,529 h and 184,538 cycles [<xref ref-type="bibr" rid="j_tar-2023-0024_ref_001">1</xref>]. These data were obtained from daily reports of defects and unplanned consumption of spare parts for these systems. Failures of instrumental equipment of avionic systems were investigated in detail. Based on calculations of their failure probability and component replacement frequency, a comprehensive system including measures and their technical and instrumental support has been developed to improve maintenance productivity. Such a system requires relatively inexpensive components, is simple and can be used in the operation of this type of aircraft.</p> </abstract>ARTICLEtrue Modelling of Static Aeroelastic Deformations of Slender Wing in Aerodynamic Design<abstract> <title style='display:none'>Abstract</title> <p>The article presents the validation of two methods for analyzing the aerodynamic properties of the aircraft wing concerning aeroelastic effects. The first method is based on low-cost computational models (Euler–Bernoulli Beam Model and Vortex Lattice Method [VLM]). Its primary objective is to estimate the wing’s deformation early in the design stages and during the automatic optimization process. The second one is a method that uses solutions of unsteady Navier–Stokes equations (URANS). This method suits early design, particularly for unconventional designs or flight conditions exceeding lowfidelity method limits. The coupling of the flow and structural models was done by Radial Basis Functions implemented as a user-defined module in the ANSYS Fluent solver. The structural model has variants for linear and nonlinear wing deformations. Features enhancing applicability for real-life applications, such as the definition of deformable and nondeformable mesh zones with smooth transition between them, have been included in this method. A rectangular wing of a high-altitude long-endurance (HALE) aeroplane, built based on the NACA 0012 profile, was used to validate both methods. The resulting deflections and twists of the wing have been compared with reference data for the linear and nonlinear variants of the model.</p> </abstract>ARTICLEtrue Eddy Current System for Aircraft Structure Inspection<abstract> <title style='display:none'>Abstract</title> <p>Aircraft part diagnostics are crucial during both production and maintenance, with eddy current nondestructive testing (ECNDT) being the method of choice due to its cost-effectiveness, informativeness, productivity, and reliability. ECNDT excels regardless of surface condition or coatings. It’s employed for diagnosing various aircraft components, necessitating diverse transducer types, excitation modes, and advanced signal processing. To improve ECNDT, this article explores integrating harmonic and impulse excitation modes in a single tool to enhance informativeness. Building upon a wireless eddy current system, the authors propose a comprehensive method for processing and displaying information suitable for object condition monitoring systems. The system includes automated transducer mode control and experimental data processing algorithms. The constant expansion of tested objects and new materials underscores the need to enhance the theoretical foundations of eddy current non-destructive testing, refine signal processing techniques, and identify informative signs. This demands the development of new automated ECNDT tools, and this article offers a promising avenue for improvement. The results include model and experimental tests of system components, showcasing the potential of this approach to enhance ECNDT effectiveness, automation, and informativeness in the realm of aircraft part diagnostics.</p> </abstract>ARTICLEtrue Strapdown Inertial Navigation System Performance by Self-Compensation of Inertial Sensor Errors<abstract> <title style='display:none'>Abstract</title> <p>Microelectromechanical systems (MEMS)-based strapdown navigation systems offer advantages such as small size, low cost and minimal power consumption. However, MEMS sensors are prone to significant low-frequency noise and poor bias repeatability, which can lead to navigational errors over time. These errors make them unsuitable for autonomous navigation applications, even with frequent recalibration. One way in which to solve this problem is by using the rotation modulation (RM) method. This approach is widely recognised but has only been successful with precise laser and fiber optic gyroscopes equipped with precise rotating platforms. This article focuses on the potential of adapting the RM method for the case of inexpensive MEMS sensors that can significantly improve navigation performance, while maintaining the benefits of microelectromechanical technologies. Potential issues of implementation were discussed, and corresponding requirements were formulated. The proposed optimal computation scheme was verified during static tests of the developed inertial measurement unit (IMU). Further steps in studying the adaptation of the RM method for MEMS sensors have also been outlined.</p> </abstract>ARTICLEtrue Operating Window in Selective Laser Melting Processes<abstract> <title style='display:none'>Abstract</title> <p>Selective laser melting (SLM) is one of the most effective methods of additive manufacturing (AM). It is used to manufacture products with very complex geometries using a wide range of materials. Practical process conditions are limited by the occurrence of undesirable melting instabilities that degrade the surface quality and lead to product defects. These disadvantages are related to the thermal limitations of the SLM process. The lower thermal limit is due to the need to completely melt the powder layer and partially remelt the underlying layer again to ensure proper bonding between the layers. Exceeding the upper thermal limit in the molten metal pool may cause extensive evaporation, boiling and ejection of molten metal droplets outside the melting area. The article presents an approach and methodology that enable the determination of thermal limits and the operating window of SLM/selective laser sintering (SLS) processes in a relatively simple way. The studies have been performed using various settings of SLM process parameters. The usefulness of the preliminary determination of thermal limitations and approximate prediction of operating window of SLM has been confirmed experimentally and by more accurate computer simulation.</p> </abstract>ARTICLEtrue Tonal Noise Prediction Using Urans<abstract> <title style='display:none'>Abstract</title> <p>To examine the feasibility of the laminar boundary layer (LBL), vortex shedding (VS) tonal noise modelling using unsteady Reynolds-averaged Navier–Stokes (URANS) was investigated for the non-symmetric S834 airfoil. A transition SST turbulence model was used to model the laminar-turbulent transition and its vital influence on the laminar bubble and hydrodynamic instabilities generation. The influence of turbulence on the unsteady vortex patterns was investigated. Hence, the hybrid aeroacoustic analysis with Lighthill analogy was conducted to obtain the acoustic pressure field. The approach allowed us to model hydrodynamic instabilities and the resulting VS tonal noise. The frequency of VS matched the experimental data, giving the same 1/3 octave tonal peak only for a limited freestream turbulence regime. The simplification of the present method did not allow us to model the aeroacoustic feedback loop, and resulted in lack of instabilities for higher freestream turbulence.</p> </abstract>ARTICLEtrue of Chipped Fiber Languor on the Bending Behavior of Concrete Beam Elements<abstract> <title style='display:none'>Abstract</title> <p>This article studies the behavior of concrete beams reinforced with metal fibers (chips) randomly arranged in concrete, to improve ductility and bending stiffness and limit crack openings. These fibers come from machining waste from steel parts. The fibers are characterized for mechanical resistance and tearing. Three series of tests were carried out for languor respectively L = 4 cm, L = 5 cm and L = 6 cm. Bending tests (three-point bending) are carried out on prismatic specimens of dimensions [10x20x120] cm<sup>3</sup>. Compression tests are carried out on cylinders with a diameter of Ø16 cm and a height of H32 cm in order to determine the mechanical properties of the concrete used. The composition of the concrete is determined by the experimental method known as “Dreux-Gorisse”. Two fiber contents are retained for this study (W= 0.6% and W= 0.8%) and a BT control concrete (W=0%) with W: fiber contents in the concrete, of the same composition as the matrix is developed for serve as a reference. The confrontation and comparison of the different results obtained show that the fibers with languor L=6 cm confer significant ductility to the material after cracking of the concrete, better than the other languor’s (L= 4 cm and 5 cm) with numbers of undulations (spirals) n=3.5and 6. Also, the fibers used limit bending cracks and improve strength and rigidity.</p> </abstract>ARTICLEtrue Pollutant Dispersion Modeling Methods<abstract> <title style='display:none'>Abstract</title> <p>The method of modeling and simulating different phenomena in various fields of scientific knowledge is an essential part of many branches of science, each of which has specific types of models. Using mathematical methods, these models try to simulate a real situation by means of numerical analysis that describes the relationships between the characteristic quantities of air pollution phenomena, such as emissions, meteorology atmospheric concentrations of pollutants, deposition, and other factors. Air and water pollution measurements give information about the environmental concentrations of pollutants scattered by different sources but can only describe the phenomena involved qualitatively, at specific locations and times, without identifying the causes that lead to pollution problems. However, models of air and groundwater pollution can provide a deterministic description of the problems of air or water quality, including an analysis of the factors and causes of the pollution phenomenon (emission sources, meteorological processes and chemical and physical changes), and some guidance for implementing measures to mitigate these phenomena of environmental pollution. Due to the ability of these methods to establish the relative importance of relevant processes, they play an important role in current day science.</p> </abstract>ARTICLEtrue Particulate Monitoring System for Industrial Complex to Analyze the Dust Suppressing Capacity<abstract> <title style='display:none'>Abstract</title> <p>The rising levels of air pollution in the industrial environment necessitate its monitoring near the sources. The green wall around the industries is a novel and popular to mitigate the impact of Particulate Matter (PM). Such industrial mitigation cannot be monitored through a limited quantity AQ monitoring station at ground level. This paper demonstrates the application of drone aided particulate matter monitoring system to measure the above-ground level PM levels. The drone-aided AQ monitoring system was employed near the thermal power plant to calculate the attenuation factor potential due to the plantation of a green bamboo belt. The wind rose was plotted to understand the wind pattern and dispersion direction of the PM. The dust suppression due to the green wall of the bamboo is calculated using a drone-enabled PM sensor module. The PM (Particulate Matter) data at the ground level was 39 % low compared to the upper height. The PM concentration was significantly high at the height of 30 m Above Ground Level (AGL). The bamboo plant plays a crucial role in dust suppression. The overall results pointed out that the calibrated, lightweight portable drone-aided sensor monitoring system can be reliable for monitoring source-specific industries.</p> </abstract>ARTICLEtrue Cement Valuation: An Optimistic Approach to Carbon Dioxide Reduction<abstract> <title style='display:none'>Abstract</title> <p>This article discusses a variety of more recent alternatives to Portland cement (OPC) that can lower energy consumption and greenhouse gas emissions. Some of these new binders can be made utilizing fuels and low-grade industrial waste. Only after thorough examination of various physico-mechanical, microstructural, and durability properties can the practical viability of these alternative binders be substantiated .In this review paper seven important alternative cementitious binder systems i.e. Supplemental cementitious in place of OPC in some cases, Industrial By-Products, Alternative cements, Concrete Made Using Garbage as Aggregate, Carbona table Calcium Silicate Cement, Cements With a Calcium Hydro silicate Base, Eggshell waste for sustainable construction materials are discussed. It was deduced that all of the more recent cementitious binders could be created utilizing industrial wastes such as low-grade limestone or clay, fly ash, and slags. This would result in the achievement of the desired physico-mechanical and durability properties, as well as a decrease in cost and energy consumption of between 20 and 58 percent. In addition, the creation of the aforementioned alternative binder results in a reduction of greenhouse gases that is anywhere from 15–55%.</p> </abstract>ARTICLEtrue of Geotextile Reinforced Gravel Roads Using Giroud and Han Approach for Indian Condition<abstract> <title style='display:none'>Abstract</title> <p>Sustainable pavement is the need of the hour using the mechanistic and robust pavement design approach, eliminating empiricism in the present IRC SP 72-2015 design guidelines, if any. Giroud and Han (2004) (GH) approach has confirmed existing empiricism in IRC SP 72-2015 design guidelines and permits the use of locally available material, thus saving transportation costs and reducing air pollution. IRC SP 72 – 2015 recommends design thickness only for the unreinforced condition in gravel roads for the maximum rut of 50mm. This paper presents the comparative study of an unreinforced and geotextile-reinforced gravel road design for Indian conditions with the rut as a vital design parameter using the GH method for subgrade classes with 2% to 5% CBR and the maximum traffic count of 100,000. The proposed unique equation provides Allowable Rut Depth (ARD) based aggregate thickness for 10,000 to 100,000 traffic count apart from simplifying the complex procedure of the GH approach for IRC SP 72-2015 data. The unique equation’s result reveals an increase of 22.65% in aggregate thickness is attributed to the increase in ARD of 30mm using locally available poor aggregates. This confirms the practical relevance of ARD in pavement design that may help in planning maintenance programs and road rehabilitation strategies. The results obtained from the unique equation match 85 to 100% with GH results. Saving up to 36.5% to 76.9% of costly aggregate is found in the case of geotextile-reinforced gravel roads in Indian conditions.</p> </abstract>ARTICLEtrue Wall Block from Thin Waste Plastics Wrap and Waste Engine Oil Without and With Filling Material<abstract> <title style='display:none'>Abstract</title> <p>In order to utilize waste materials as building component, waste of thin plastics wrap and waste engine oil without and with rice husk ash as filler can be used for producing Plastic Wall Block (PWB). The objective was to evaluate the PWB engineering properties. The waste plastic wrap was shredded or cut off to sizes about 5-10mm. The waste engine oil without or with rice husk ash were heated at 200°C, then the shredded plastic poured into hot oil and evenly mixed. The mixture was casted in a metal mould and compacted at temperature of 125-110°C using a Marshall hummer for one blow to give even and flat surface shape then cooled down to form sample with average size of 100x100x80mm. It was obtained that the soaked compressive strength can exceed 25kg/cm<sup>2</sup> which is the minimum value targeted, with initial rate of suction range about 0.0149-0.1012 kg/m<sup>2</sup>.minute; porosity in a range of 0.62-1.48 %, and water absorption of 0.0481-2.2185 %.</p> </abstract>ARTICLEtrue Analysis of Historical Cantilevered Stone Staircases<abstract> <title style='display:none'>Abstract</title> <p>This paper studies the behaviour of historical cantilevered stone staircases. In Transylvania these types of stairs are found mainly in buildings classified as historical monuments built until the 1920s. Understanding the behaviour of historical staircases is essential when proposing consolidation or restoration interventions in buildings. In this work, structural analyses on simple models of staircases made of stone elements are proposed in order to investigate the stiffness of the assembly, the stresses that appear in the elements, deformations, the influence of the railings in the overall behaviour and the simulation of the breaking of a single individual step. The types of staircases investigated in this paper are existing historical structures that currently are no longer built from scratch, so the purpose of the calculation is not to dimension but to verify the existing structure.</p> </abstract>ARTICLEtrue Behavior of the Clay Cores at the Bougdoura Dam Using Ansys Software<abstract> <title style='display:none'>Abstract</title> <p>The creep of fine soils is due to the viscous properties of the assembly of mineral particles accompanied of adsorbed water which forms intergranular skeleton. It is evident during the secondary consolidation that the effective stresses are constant, the deformation extends over time. Rock fill dams with clay sealing cores deformed during exploitation. During commissioning of the core, clay undergoes. Creep is a major characteristic of the nonlinear behaviour of materials, in which the material continues to become deformed under a constant load. It can cause considerable deformations of the works (two to three times instantaneous strain in three years). This study presents a prediction of the creep behavior of a clay core in a rock dam subjected to constant hydrostatic loading for 20000 h and describes a procedure for modeling the primary and secondary creep law simulation using ANSYS software APDL In this aims, we have applied the finite element method based on a model shown in equation 8 called (Strain Hardening Model) in order to simulate a creep behavior of clay core.</p> </abstract>ARTICLEtrue of Special Cement CPA on the Characteristic Properties of Cementitious Materials Based Waste Glass Powder: Poozolanic Activity and Heat Treatment<abstract> <title style='display:none'>Abstract</title> <p>The main purpose of this study is to evaluate the effect of curing method on the compressive strength of waste glass powder as a supplementary cementitious material. This work presents an experimental study on the physico-mechanical characterization of waste glass powder (GP) as partial replacement of special cement (Algerian cement without additions CPA) based high performance cementitious material, varying the percentage of GP by 10%, 20% and 30% (by weight of cement), the curing methods: water curing at 20± 2 °C and heat curing by under accelerated drying in an oven at 100 °C (stoving). Half of the mortar samples 40x40x160 mm were treated with stoving just after demolding then kept in the open air, the other half was kept in fresh water in order to evaluate their sustainability and index of Poozolanic Activity (I) at different ages: 7, 28, 90 and 365 days. The compressive strength results showed that there is an increase in compressive strength with the increase in age of the two curing methods but the strength of all mixtures which have been stoved is inferior to those of the same mixtures preserved in fresh water at different ages. The best rate of replacement of the cement by GP is 20% following the results obtained for the compressive strength and Poozolanic Activity Index I.</p> </abstract>ARTICLEtrue Energy Efficiency in a Building Using Passive Energy-Saving Measures<abstract> <title style='display:none'>Abstract</title> <p>We are going through a time when environmental, economic and social concerns, intensely amplified by climate change, by the depletion of resources, are growing. In this context, setting targets such as reducing energy consumption in the buildings sector, energy efficiency, and the use of renewable energies are becoming a priority, both at national and international level. Improving the energy efficiency of the existing building stock is important, not only for achieving national medium-term energy efficiency targets, but also for meeting the long-term objectives of the strategy on climate change and the transition to a competitive low-carbon economy by 2050 (<ext-link ext-link-type="uri" xmlns:xlink="" xlink:href=""></ext-link>). Currently, the building is considered as a structure in a continuous evolution, which in time through maintenance, rehabilitation and modernization works will meet the requirements expressed by the user. The case study presented in the paper presents an analysis from the point of view of improving the energy efficiency, reducing the energy requirement in a building using passive energy-saving measures, that is, the additional thermal insulation of an element of the building envelope. The materials selected for this research are: expanded polystyrene, basaltic mineral wool and cellulose fibres.</p> </abstract>ARTICLEtrue