bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal Energy Management of a Hybrid Electric Helicopter for Urban Air-Mobility
Authors: Donateo Teresa , Pascalis Claudia Lucia de , Strafella Luciano , Ficarella Antonio 
Published: January 2021

Abstract
In this study, a hybrid electric helicopter for air-taxi operations is considered. The drivetrain includes a turboshaft engine and two electric machines, fed by a lithium ion battery. In previous works, some of the authors developed a simple but thorough modelling approach for the electric path of the power system that was validated by means of experimental data from literature. In this investigation simulation results from the Gas-turbine Simulation Program (GSP) commercial environment were used to develop and validate an off design model for the turboshaft. The second innovative contribution of the paper is the application of Dynamic Programming to four different missions of the helicopter to quantify the fuel saving potentiality of hybridization and also as benchmark for future online control strategies. A constraint was considered in the investigation to allow at any time the electric backup in case of engine failure. The results of DPM showed that it is possible to obtain a reduction of fuel burn from 12% to 24% (with respect to using only the engine to move the rotor) depending on the specification of the mission and the state of health of the battery. Moreover, it was proved that charging the battery on board is not necessary in this kind of application.
Wing conceptual design for the airplane with distributed electric propulsion
Authors: Hospodár Pavel , Klesa Jan , Zizkovsky Nikola 
Published: January 2021

Abstract
This paper is focused on the usage of distributed electric propulsion (DEP) in order to increase aerodynamic efficiency. A ten seats aircraft is used as a case study. New design uses the existing fuselage, tail and turboprop engine, only wing is completely redesigned. The cost function for the design procedure consists of two parts. The first one is aerodynamic efficiency, which has a primary impact on fuel consumption, and the second one is weight of the wing. Lifting line theory with blade element momentum theory is used to design a wing geometry with DEP. Optimal geometry is also verified by CFD simulation. The estimation of the wing weight is needed for the second part of the cost function. This was done by the design of elementary wing parts under CS-23 regulation. The wing is assumed as full-aluminium with two spars. The main goal of this optimization is to redesign the wing for a given range and save as much fuel as possible.
Identification of resonant vibrations of the miniature unmanned airplane with contact and non-contact measuring techniques
Authors: Olejnik Aleksander , Rogólski Robert , Szczesniak Michal 
Published: January 2021

Abstract
The paper describes application of two different vibration measurement methods for identification of natural modes of the miniature UAV. The aim of this research was to determine resonant frequencies and modes of mini-airplane within specified range of frequency values. Special measuring equipment was used including both contact and non-contact techniques. The measuring systems on equipment of the Institute of Aviation Technology in the Faculty of Mechatronics, Armament and Aerospace of Military University of Technology (Warsaw, PL) were used to conduct measurements. In traditional GVT methods a large number of sensors can be attached to the aircraft. The weight of sensors and cables is negligible in relation to the mass of the large aircraft. But for small and lightweight unmanned aerial vehicles, this could bring a significant mass component in relation to the total mass of the tested object. In this paper the methodology of GVT was presented. Two different measuring methods were applied, i.e. the contact method and the non-contact method. Using the dedicated apparatus in relation to mini-airplane, properly prepared in terms of mass distribution, rudders deflection stiffness and proper support, some resonant characteristics can be determined. The contact measuring system consists of a multi-channel analyzer, piezoelectric accelerometers, electrodynamic exciters, amplifiers, impedance heads and a computer with the Test. Lab Software. As the non-contact method a laser scanning vibrometer was used. The principle of its operation is based on the separation of the emitted laser beam. The returning beam reflected from a vibrating object is captured by the camera and compared to the reference beam. Dedicated software analyses collected data and on the basis of it creates animations of structural vibrational shapes and spectral plots within investigated frequency range. Object used for research is the mini-UAV Rybitwa – composite mini-plane with a classic aerodynamic layout manufactured in IAT MUT. In the work both measurement methods and some sample results were presented. Results referenced to dynamic properties of the mini-UAV can be applied in the future to FE model tuning.
Direct method of rigidity using Mathcad Software
Authors: Koça Odhise , Sulejmani Anis , Alimhilli Parid 
Published: January 2021

Abstract
Static indeterminate structures are difficult structures to solve by hand or using classical methods. They required data and time to solve. New methods for calculating them are Direct Method of Rigidity (DMR). These structures, increasingly complex, are finding use in various fields of engineering as well as in the field of aviation and space. Therefore, introducing these methods into aircraft structures, helicopters or space structures is a pretty nice and difficult challenge. An example of this is the structure of a helicopter [1] and through DMR methods; we determine the internal forces important for other designations. The calculation procedure goes through several stages. The structure and its elements in local and global coordinates are studied, and then we create the matrix of rigidity. Through matrix transformations, it became possible to program algorithms for solving both methods in Mathcad software. In conclusion, we have all the graphs of the moment, the shear force and the normal force required for further studies of the structure.
Mini-Multi Interface Box Simulator (MMIBS)
Authors: Barea A , Doblado J G , Crespo D , Garcia A , Soldado I , Barrera G , Leopoldo A , Prats M M , Cabanas R M 
Published: January 2021

Abstract
Today’s military and commercial aircraft avionics and general systems are built around complex networks of intelligent devices. Maintenance and troubleshooting of these systems often require access to the data bus or networks connecting the system components. Whether it is on the integration test bench, Final Assembly Line (FAL) or at the Maintenance and Repair Organization (MRO), these tasks are usually performed by means of many, expensive, heavy and intrusive equipment. The MMIBS (Mini-Multi Interface Box Simulator) is a very compact, portable, multipurpose, lightweight, low-power, and easy-of-use electronics test means intended to improve digital aircraft ground testing and maintenance troubleshooting. It is capable of perform functional testing and simulating aeronautical equipment through most common aeronautical communication interfaces, such as AFDX, CAN BUS, ARINC 429, MIL-STD-1553, RS-422, RS-232, RS-485, Discrete and Analog I/O and RVDT (Rotary Variable Differential Transformer) reading capabilities. Besides, the system is highly configurable and reprogrammable by means of intuitive Python-based scripting. System is also able to be controlled with an intuitive, user-friendly and dedicated HMI (Human Machine Interface). In this mode, the user can conform a MMIBS WIFI network, allowing multiple MMIBS operating in parallel to cover complex testing scenarios. The MMIBS device integrates all the aeronautical communication and signaling in a volume of 12x12x12cm and weight of 1200g and provides an autonomy of 5 hours. In this way, our solution combines performance, reliability, low maintenance costs, and ease-of-use to support efficient ground maintenance operations.
Drag Control by Hydrogen Injection in Shocked Stagnation Zone of Blunt Nose
Authors: Vashishtha Ashish , Callaghan Dean , Nolan Cathal 
Published: January 2021

Abstract
The main motivation of the current study is to propose a high-pressure hydrogen injection as an hybrid active flow control technique in order to manipulate the flow-field in front of a blunt nose during hypersonic flight. Hydrogen injection can lead to self-ignition under the right environment conditions in a stagnation zone, and may cause thermal heat addition through combustion and provide the counterjet effect together by pushing bow shock upstream. The axisymmetric numerical simulations for the hemispherical blunt nose are performed at a Mach 6 freestream flow with 10000 Pa pressure and 293 K temperature. The sonic and supersonic hydrogen and air injections are compared for drag reduction at the same stagnation pressure ratio PR and momentum ratio (RMA). The sonic air and hydrogen injection scenarios show similar performance in terms of drag reduction and similar SPM flow features, but hydrogen injection has a mass flow rate 3.76 times lower than air. Supersonic hydrogen injection at Mj 2.94 behaves differently than supersonic air injection and can achieve up to 60 % drag reduction at lower PR and LPM mode with lower mass flow rate. Additionally, air injection achieves a drag reduction of 40 % in SPM mode at higher PR with very high mass flow rate.
Artificial neural networks in panel method for solving aerodynamics problem
Authors: Strelets D Yu , Kataev A A , Khrustalev A L 
Published: January 2021

Abstract
The authors proposed an experimental panel method combined with an artificial neural network to solve the problems of aerodynamics with minimum computational power consumption and high accuracy. A software solution based on the proposed method has been created. A comparison with experiments and other existing solutions has been made. The proposed method is intended for solving aerodynamic problems in systems of multi-criteria optimization, as well as in related problems. For example, solutions to the problem of strength and aerodynamics in the associated wing of a civil aircraft. The proposed method and software solution based on it can open new horizons in aerospace industry optimization calculations.
Textured solar cell modeling in TCAD
Authors: Plotnikova E YU , Arsentiev A V , Harchenko M E 
Published: January 2021

Abstract
We investigate one of the promising methods for increasing the output characteristics of solar cells - surface texturing. The structures and characteristics of microcrystalline silicon solar cells are simulated. Solar Cells with different surface geometries are compared. The first type is the classic flat structure. The last and the most effective is Solar Cell with the surface in the form of microscopic pyramids separated by flat regions.
Improving the characteristics of thermoelectric generator batteries based on bismuth telluride by optimizing the parameters of hot pressing n-Bi2Te2.4Se0.6
Authors: Grebennikov A A , Bocharov A I , Makagonov V A , Kalyadin O V , Yur’yev V A , Korolev K G 
Published: January 2021

Abstract
The effect of hot pressing modes (pressing pressure and holding time under pressure) on the thermoelectric properties of n-type bismuth telluride Bi2Te2,4Se0,6 doped with Hg2Cl2 was investigated. Samples were obtained by powder metallurgy technology - the synthesis of a chemical compound followed by hot pressing. A change in the hot pressing modes does not significantly influence the value of the thermo-EMF and conductivity of the samples. A change in the hot pressing mode significantly influences on the value of thermal conductivity. Both the increase of pressing pressure and the increase of the holding time under pressure leads to a decrease in the thermal conductivity of the material. Thus, the thermoelectric figure of merit of bismuth telluride can be increased by increasing the pressing pressure, holding time under pressure, or both parameters simultaneously. The increase of the thermoelectric figure of merit was 15% in the investigated samples. As a result of the tests of thermoelectric generator batteries, it was found that the output power of the battery made from a material with a high figure of merit was 27 W at temperatures 70 °C on the cold side, 300 °C on the hot side. The output power of the battery which was made from the material with a lower figure of merit was 25 W at a similar temperature regime.
Heat consumption of apartment buildings during the heating period
Authors: Kitaev D N , Cheremisin A V , Hasanov Z S , Mikhailov A A 
Published: January 2021

Abstract
The work is devoted to the search for methods for calculating the heat consumption of multi-apartment residential buildings for heating and hot water supply, which allows obtaining the closest results to the actual ones. Three current methods of calculating heat consumption and one canceled, but often used in heat supply contracts, were used. Based on a comparison of the actual data obtained by the common-house heat energy metering devices and the calculated values, the possible deviations in the heat consumption of multi-apartment residential buildings of different floors, area and year of construction, ranging from 49.73 to 177.77%, were found. An economic assessment of the consequences of using the most inadequate methods has been carried out. It was found that when using methods with extreme error values, payments for the heat supply service from one house can differ by 3.6 times.
Analysis of technical condition and development of practical recommendations to improve the reliability of steam turbine control system
Authors: Sultanov M M , Lunenko V S , Chubko Y M 
Published: January 2021

Abstract
Questions of ensuring reliability and safety of operation of complex technical systems are relevant during the operation of power equipment of thermal plant (TPP). The paper presents a generalized statistical analysis of defects and damages over the past 15 years in the control systems of steam turbines of types ET (extraction turbine) and IET (industrial extraction turbine), with an installed capacity of 50 to 135 MW. As a result of the calculation study, the main cause-and-effect relationships of the resulting defects that lead to an emergency stop of the turbines were identified. This paper presents the results of the analysis of defects in steam turbine control systems and provides recommendations for eliminating and preventing unplanned downtime due to an emergency shutdown of turbine units.
Application of digital twins of equipment for managing complex renewable energy
Authors: Smirnov A A , Lunenko V S , Boldyrev I A 
Published: January 2021

Abstract
The paper describes a control system for renewable energy complexes with optimization of operating modes based on digital twins of equipment. The application of digital twins allowed us to develop a simulator that simulates the main processes occurring in the ground heat pump system. The simulator allows: to perform computer experiments to study different modes of Polygon operation; to demonstrate the physical essence of the ongoing processes to form the qualifications and skills of students in the field of non-traditional and renewable sources of electric and thermal energy. The use of digital twins also allows the implementation of a renewable energy combination management system to improve the energy efficiency of hybrid power complexes. The algorithm developed by the authors for selecting combinations of renewable energy sources to increase the energy efficiency of the complexes takes into account the current values of the operating parameters of the equipment, the forecast of energy consumption, as well as the forecast of power generation by each of the components of the complex.
Reliability assessment of gas supply to individual consumers using digital modeling
Authors: Martynenko G N , Petrikeeva N A , Gorskikh S A , Gorskikh A A 
Published: January 2021

Abstract
In this work, an algorithm for assessing the reliability of gas supply for individual enterprises was developed and a block diagram of the application program was compiled. The calculation was made in accordance with the principles of the theory of the probability of disconnecting consumers using digital modeling.
Hardware solutions for connecting static capacitor banks in high voltage electrical networks
Authors: Babenko V V , Khaichenko I A , Nefedov Yu V , Krysanov V N 
Published: January 2021

Abstract
This work is dedicated to finding effective hardware solutions for implementing the power part of reactive power compensation units for high voltage electric networks. It shows the possibility of cooperative usage of thyristor and electromechanical key elements for switching static capacitor batteries in high-voltage networks. Based on the suggested hardware solutions main technical and cost characteristics of thyristor capacitor units are determined. The rationality of their use in industrial high-voltage electrical networks of 6-10 kV is concluded. It is shown that the usage of hybrid thyristor capacitor units allows one to reduce the expenses, to provide the required range of accuracy of reactive power regulation, to cut power losses in the network, to guarantee normalized voltage level in the load nodes and to increase the reliability and duration of power equipment life cycle.
Numerical study of the effects of pressure gradient on the heat transfer in the KMS heat exchanger channel
Authors: Petrova N , Tsynaeva A 
Published: January 2021

Abstract
The work is devoted to studying the influence of the pressure gradient on the heat transfer intensity in the channel of the KMS air heater. The aim of the work is to develop methods for improving the heat engineering characteristics of a heat exchanger using a pressure gradient. Numerical simulation is implemented based on the RANS approach using the Code Saturne software package using the k-w-sst turbulence model. The simulation conditions were set in accordance with the manufacturer’s instructions for the KMS-2 type air heat exchanger. In the work, the heat transfer coefficient was studied in the presence of a longitudinal pressure gradient in the heat exchanger channel from the gas path. As a result of the simulation, data were obtained on the effect of the pressure gradient on the heat transfer intensity for different working fluids in the channel of an advanced heat exchanger.
Flow simulation of petroleum diesel fuel and rapeseed oil in the nozzle of a diesel injector
Authors: Sa Bowen , Markov Vladimir A , Kamaltdinov Vyacheslav G , Neverov Vsevolod A 
Published: January 2021

Abstract
The flow of petroleum diesel fuel (DF) and rapeseed oil (RO) in the nozzle of a diesel injector under operating conditions was simulated numerically. Investigated the general flow characteristics, such as mass flow rate, discharge coefficient, injection rate, averaged turbulent kinetic energy at the nozzle outlet and volume concentration of fuel vapor in the nozzle, and local flow parameters. The saturation pressure of RO is determined by summing the saturation pressure of constituting RO triacylglycerides. At a fuel temperature of 40 °C, the mass flow rate, discharge coefficient, injection velocity and turbulent intensity at the outlet of the nozzle hole for RO are significantly less than petroleum DF for all injection pressures, and the RO cavitation level (fuel vapor) in the nozzle hole is also lower than petroleum DF due to extremely slow saturation pressure of RO. However, this difference between RO and petroleum DF decreases with increasing injection pressure due to the different cavitation levels of DF at different injection pressures.
Investigation of the influence of gravitational forces on the thermal-hydraulic processes of power plants
Authors: Sataev A A , Andreev V V , Duntsev A V , Novikov D I , Berezin A A 
Published: January 2021

Abstract
Today, improving the safety of nuclear power plants is one of the main problems. Obviously, heat and mass transfer processes have a great influence on complex phenomena occurring in the reactor plant. Currently, special software systems are being developed that can describe these processes (Computational Fluid Dynamics (CFD)). However, they do not take into account the influence of external gravitational forces. They occur when the spatial position of an object changes. In the case of ship-based nuclear power plants, the development of technical specifications should include a mandatory requirement for trouble-free operation when affected by pitching and rolling. The paper describes the study of the effect of shipboard pitching on the mixing processes of non-isothermal flows in a small-scale model. Based on the analysis of the results obtained, it can be concluded that the external dynamic force has a negative effect on the mixing of non-isothermal flows.
Integration of solar plants into energy systems in apartment residential buildings
Authors: Chudinov D M , Kolosov A I , Shchukina T V , Zverkov A P 
Published: January 2021

Abstract
Non-traditional renewable energy resources (solar radiation, wind energy, etc.), alternative thermal and electric generators have incontestable positive qualities in comparison with fossil fuel (natural gas, coal, fuel oil), classical systems: relative environmental friendliness, vast total reserves, low operational costs, reliability, ease of management. The scale of their implementation in the Central Black Earth Region can be limited by high initial capital investments, the value of the energy resource, and low awareness of the population. The article presents the results of modeling solar plants functioning during their integration into traditional energy systems of apartment residential buildings. In the article we demonstrate technical and economic indicators of projected and modernized engineering heating services in the city of Voronezh. The technically viable period of use is spring-summer-autumn. Economic indicators put solar systems into the experimental category.
Widely linewidth tunable lasers through cascaded four-wave mixing based phase modulation amplification
Authors: Vikram B S , Prakash Roopa , Supradeepa V R 
Published: January 2021

Abstract
We demonstrate wide-range linewidth-tuning of a narrow-linewidth laser in the C-band up to 40 GHz through cascaded four-wave mixing (CFWM) based phase modulation amplification. Stimulated Brillouin scattering (SBS) severely limits the power scaling of narrow-linewidth lasers. Continuous tuning of the linewidth or temporal coherence of the laser to mitigate SBS is conventionally achieved through external phase modulation with white noise or other RF waveforms. However, the range of linewidth tuning is limited by the bandwidth and power of the electro-optic modulator. We overcome this through the use of FWM as a linewidth multiplier. To achieve linewidth multiplication, two tunable pumps line-broadened in electro-optic phase modulators with white noise are power scaled and propagated through highly nonlinear fiber. We achieve linewidth tuning up to ∼4 GHz using control of the noise waveform, while CFWM achieves a 10× multiplication of linewidth up to 40 GHz at a fixed wavelength. Linewidth tuning can be further scaled through power scaling or cascading multiple nonlinear stages. The proposed technique would be useful in nonlinearity control in narrow-linewidth laser amplifiers, high-resolution optical imaging, LIDAR, and infrared spectroscopy.