Table of contents

ABOUT THE CONFERENCE

7th International Conference of Computational Methods in Engineering Science (CMES'2022), 24-26 November 2022, Zamość, Poland.

The main objective of the CMES conference is the development of engineering sciences, numerical and experimental techniques, broaden experience, and good practices by representatives of the scientific community and industry. The conference allows the exchange of knowledge between different research domestic and foreign centres representing various fields of engineering science and technology.

The organizers of the conference are Department of Thermodynamics, Fluid Mechanics and Aircraft Propulsion, Department of Machine Engineering Fundamentals and Mechatronics, Department of Materials Engineering (Mechanical Engineering Faculty of Lublin University of Technology), Department of Computer Science (Faculty of Electrical Engineering and Computer Science of Lublin University of Technology), Department of Organisation of Enterprise (Faculty of Management of Lublin University of Technology), Department of Renewable Energy Engineering and Department of Biomass and Waste Conversion in Biofuels (Faculty of Environmental Engineering of Lublin University of Technology), as well as Department of Airframe and Engine (Aeronautics Faculty of Polish Air Force University).

List of Topics, Organizing Committee, Scientific Committee are available in this Pdf.

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing Publishing.

• Type of peer review: Single Anonymous

• Conference submission management system: Morressier

• Number of submissions received: 21

• Number of submissions sent for review: 20

• Number of submissions accepted: 14

• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 66.7

• Average number of reviews per paper: 2.5

• Total number of reviewers involved: 24

• Contact person for queries:

• Name: Zbigniew Czyz

• Email: z.czyz@pollub.pl

• Affiliation: Polish Air Force University

Nowadays, different perovskite structures are widely investigated because they can be potentially used in many branches of industry. If two materials are deposited alternately on a substrate, then a superlattice having some unique properties can be formed. However, X-ray intensity distributions for perovskite superlattices, especially for very thin films, are difficult to be computationally determined, because many different parameters need to be considered to reproduce a superstructure of a sample. The main purpose of this work is to demonstrate how basic intensity distributions can be generated for perovskites, XRD technique and how to improve results using specific numerical methods. The computer application with a user-friendly graphical interface has been developed employing Unity software (with 3D graphics tools) and Oracle Database (through Oracle Cloud Infrastructure). The calculations are based on the kinematical theory of diffraction. The values of some important parameters and the results are stored in the assigned database. It is assumed that epitaxial superlattices can be prepared on substrates using molecular beam epitaxy or pulsed laser deposition methods. The desktop application allows for designing samples of different thicknesses and combinations of monolayers. The results are more realistic if Monte Carlo simulations are done although longer computation time is required. The software developed should be helpful to compare in detail virtual model results with experimental data.

The last decade has brought a significant increase in the number of heliports built in Poland mostly for medical purposes to enable helicopter medical transport directly to the hospital. Some hospitals, however, could not build ground-level heliports due to limited space in densely populated areas. The solution to this problem can be elevated rooftop heliports. The main drawback of elevated heliports can be vibrations of the whole building, caused primarily by unsteady rotor slipstream which impinges on the heliport surface during take-off and landing. It is especially awkward in case of medical heliports due to strict vibration requirements. The frequency of these vibrations is known to equal a blade passing frequency of about 25 Hz for the Eurocopter EC-135 that is commonly used by, e.g. Polish medical service. However, the pressure measurements made by the authors showed that a low-frequency component of pressure oscillations of a significant amplitude is recorded in the outer part of the rotor disc. To explain the source of this component, we performed a PIV measurement of the velocity field in rotor slipstream. An object of investigation was the remotely controlled T-REX 450 Pro helicopter with a rotor diameter of 0.7 m. A key conclusion is that tip vortices from blade tips are located roughly along the Archimedean spiral, but vortices distanced from the blade tip shift up and down (or towards the blade tip and rotor axis) in a periodical manner.

Recently, the design of biologically inspired thin-walled structures has been increasingly popular due to the successful adaptation of biological organisms to their environments due to millions of years of evolution. Plants with high bending resistance to counter the effect of wind forces on slender and tall stalks can be found in nature. To this end, this paper investigates the bending crashworthiness of mechanical structures inspired by sugar cane (Saccharum officinarum). The biological patterns of sugar cane were obtained with a Scanning Electron Microscope, and five bionic thin-walled structures (BTWS) were considered. In all cases, the structures were modeled with 6063-T5 aluminum and numerically evaluated using the finite element method using a three-point bending test. The effects of cross-section configuration on the crashworthiness performance of the structure were investigated. Our results show a better version of the BTWSs relative to a typical circular profile. An increase in energy absorption from 15.60% to 40.27% was computed. The best CFE performance was obtained for a structure defined by a central octagon surrounded by smaller trapeziums. Such a structure is therefore highly recommended for bending crashworthiness applications.

The paper analyses the feasibility of determining the parameters of a heat exchanger operating in the crop production and realising low-temperature heat recovery from biological processes. For the first time, the Flownex 8.7 Simulation Environment has been used for this purpose. The temperature of the waste water was between 20 and 30°C. On the basis of the simulations, the power of the heat exchanger is determined to be 1 MW. The heat exchanger can efficiently heat up cold water from a deep well (7-10°C) to an assumed temperature of 19.7°C. The results from the simulation calculations correspond to the results obtained under actual conditions within a range of up to 2%.

Air quality control and its prediction are particularly important for human health and life. Sulfur dioxide constitutes one of the air pollutants that play an important role in air quality pollution. An artificial neural network model was employed to forecast the levels of sulfur dioxide in the air of Zamość (Poland). The measured data of the meteorological station of Zamość in 2017-2019 were used for the model. Temperature (T), relative humidity (RH), wind speed (WS), wind direction (WD), SO₂, PM10, NO₂, NOx, CO, O₃, C₆H₆ were used as input parameters for building the neural network model. Regression value (R) and Mean Squared Error (MSE) were used to estimation the model. The results show that neural network is capable of predicting the sulfur dioxide levels in the air.

As a result of human activities, river valleys have changed: river beds have been transformed as a result of their regulation and dam construction. This paper presents unsupervised machine learning techniques to distinguish arthropod communities and attempts to explain the ecological priorities of individual species based on them. Data on a group of 95 species of carabid beetles from 16 habitats on the floodplains of two rivers - Bytytsia and Strilka (Dnipro basin, Ukraine). Analyses were performed using the program R version 4.1.1. Fuzzy clustering was performed using the fanny function from the R cluster package, and visualization of the results was performed using the t-SNE method from the Rtsne package. In our analysis, the following habitat type characteristics were chosen to distinguish communities: closed (forest) or open (grassland). According to the results of fuzzy clustering, out of 95 carabid species, 37 species were selected whose probability of belonging to their cluster was at least 0.95. These species form distinct three groups. The first group of carabid species is associated with forest sites in Bytytsia. The second group is connected with occurrence on meadow sites in Strilka. The third group of species is connected mainly with the meadow sites of the Bytytsia River. Established groups of species reflect the current ecological situation on floodplains and the influence of human activities on it.

Requirements for the continuous improvement of the quality of wastewater discharged to a receiving water body have led to the development of many devices used in biological treatment. Current research in water and wastewater solutions often focuses on finding energy-efficient solutions that have the least negative impact on the environment while reducing operating costs. Treatment systems commonly use the properties of microorganism structures in the form of activated sludge flocs to remove organic and nutrient compounds contained in wastewater. An important part of this solution is the use of a mixing and aeration system in the appropriate configuration. In a wastewater treatment plant with a biological part operating with SBR technology, many types of mixing equipment are used. This article presents the use of an innovative mixing system in sequential batch bioreactors in which activated sludge is the process medium.

This paper presents a model of an electric car based on the BMW i3 whose low-voltage electrical system and traction battery were supported by a photovoltaic system installed on the body of the vehicle. The photovoltaic system was installed on the roof, side doors and bonnet. The 350 Wp (Watts peak) system was made of semiflex panels. The input parameters for the model were the measurements taken during the simulated annual operation of the vehicle as driving time, weather conditions and their switching times. During stationary tests, the power of individual electrical consumers was measured and its maximum was 1.1 kW. The model included data on the electricity consumption for driving a given distance. The amount of electricity generated by the photovoltaic system was related to a stationary system of 4 kWp. The degree of shading and curtailment of energy generated by the photovoltaic system was measured during testing on a vehicle driving in urban conditions. In the vehicle under analysis, an additional energy stream supplied the 12 V electrical consumers and recharged the battery. The traction battery used to drive the vehicle during such a power supply scenario may increase the vehicle range by about 16% on average.

Nitrous oxide (N₂O), considered a major greenhouse gas (GHG) in wastewater treatment plants (WWTPs), is produced during both nitrification and denitrification processes; hence, it needs to be controlled by internal and external strategies. Various factors, such as DO, temperature, and pH, could be incorporated into the mitigation of emissions in WWTPs. In this research, potential operational strategies were investigated in order to find the optimal range for DO and temperature for controlling the N₂O production during the nitrification process. In parallel, the activity of nitrite oxidizing bacteria (NOB) could also be limited under optimal conditions to make the process more cost-effective and energy-saving. In this regard, under a lab-scale environment, DO = 0.7 mg/l was detected as the optimal range for inhibiting NOB activity and maintaining AOB activity. Moreover, the importance of developing mathematical modelling methods has gained significant attention in order to better understand the possibility of minimizing GHG in WWTPs. In this study, advanced mathematical modelling methods were used for simulating the kinetics of the nitrification process to determine the interaction among different operating factors compared to nitrification rates.

Deployable cable nets have been proposed as promising systems for the active removal of space debris. The modelling and analysis of such systems during deployment, capture, and post-capture phases are crucial for the effective design of an operative mission. To this aim, accurate and effective simulation tools are necessary. We propose a finite element model of the cable net with lumped nodal masses and first-order cable elements. The nodal positions are assumed as the main unknowns of the problem. The large displacements and finite deformations are described by the Green-Lagrange strain tensor. The cable elements are assumed to react only in tension. Global damping is considered in line with Rayleigh's hypothesis. The governing equations are solved numerically by means of the Runge-Kutta method with a variable time step. As an illustrative example, we present the simulation of the in-plane deployment of a planar, square-mesh net. The proposed approach turns out to be computationally effective, even if the accuracy of the numerical integration scheme needs to be improved, particularly in the final stages of deployment.

A cataract is a disease of the 21st century. In highly developed countries, the opacification of the intraocular lens is removed and replaced with an implant. This article discusses the essential aspects related to the construction of implants that imitate the natural lens of the eyeball. The research was carried out owing to X-ray microtomography. Observer design differences in the two lenses' structures contribute to the implant's quality in question. The study aimed to check and compare two types of implants in terms of the design and manufacturing quality of the given lenses. The common element of the implants in question was their material and manufacturer. Lenses of the same material were used to maintain the same optics. The results gave a comparison in terms of the quality of the product in terms of the creation and modelling of the lenses than the properties of the material itself from which they were made.

The non-destructive testing of welded joints is a key issue in welding technology and processes. It is especially crucial for estimation of product quality. Among others methods, visual testing is the most fundamental. In most cases, it is made manually, which can introduce some problems resulting from the lack of objectivity and fatigue of the controlling person. This paper is an attempt of changing a mode of visual inspection. The proposed system is based on image analysis of welded joints. The welding imperfections were correlated with quality levels according to the ISO 5817 standard. For the original inspection system, six the most fundamental imperfections have been selected. The main idea of this system is a detection of selected welding imperfections and, based on acceptance criteria, assigning welded joints for the appropriate quality level. In order to validate the correct operation of the proposed system, the same welded joints have been subjected to conventional manual visual inspection. The compliance of the results was more than 90%, and the speed of visual examinations was more than 10 times higher than in the manual method.

This work deals with a comparative numerical finite volume method of airflow for a 3D airframe model. The analyzed airframe model allowed 3-vector thrust directing while using the geometry of the inverted delta, which increases lift force area, allows for vertical take-off and landing, as well as full control of its flight using rotating propulsion nacelles and an airframe control system. The airframe model dimensions were 3900 x 3250 x 915 mm, enabling the installation of components of specific dimensions. CFD analysis using a four-equation transition SST model with automatic surface roughness and initial conditions: T = 288K, viscosity η= 1.7894 10−5 $\frac{kg}{m\cdot s}$ and was carried out in the FLUENT module of ANSYS 16.0. For each simulation, 2000 iterations were performed with the intention of achieving a convergence of all residuals below 110^-3 using a calculation mesh consisting of 500,000 elements and 150,000 nodes. The model uses aerodynamic profile geometries: CLARK Y, NACA 6409, and NACA 2414, which are provided to obtain the optimal aerodynamic characteristics and determine the optimal range of angles of attack for the designed solution. Those angles of attack were in the range of α = 5 ÷ 10° in which the highest excellence coefficient of the carrier airfoil profile occurs. For those values of parameters optimal lift and drag forces were determined

A nonlinear energy harvester with asymmetric potential wells is studied numerically. An energy transducing piezoelectric patch is attached to the cantilever elastic beam to harvest kinetic energy of the moving frame. To obtain an asymmetric effect in the double well potential induced by permanent magnets, an elastic ferromagnetic beam resonator misaligned with respect to the magnets' distribution axis of symmetry was used. The system response under the frequency-swept excitation reporting bifurcations to subharmonic and chaotic solutions was analysed. The sensitivity of the system solutions to the parameters responsible for potential asymmetry and electro-mechanical coupling was also investigated.