Air Craft Research Articles

A Neural-Metaheuristic Kalman Filter for Moving Microburst Wind Shear Identification

Microburst wind shears (MB) are powerful localized three dimensional (3D) columns of wind that occur when cooled air drops from the base of thunderstorms at high speeds. They eventually hit the ground and spread out in all directions. As such MBs are considered a major atmospheric hazard for aircrafts (ACs), especially in terminal flight phases. Though pilots train regularly to survive it, yet the most recommended practice within the aviation community is to avoid its encounter upon detection. Some modern aircrafts have predictive wind shear warning systems, but they have limited short range capability and do not provide quantitative data for engineering application. In this sense, accurate onboard detection and identification of MBs and its characteristics is of importance for flight safety, whose success can lead to design of automatic flight control systems (FCSs) that reduce the risk of aircraft crash landings and accidents. Even though there are some studies on FCS designs for MB encounter, research on MB identification is rare but ongoing. To this aim, the present study is among the firsts that focuses on online identification of multiple and moving MB parameters using onboard aircraft air data and inertial sensors. The identification task is initially performed using the aircraft six degrees of freedom (6DoF) equations of motion (EOM) integrated with a 3D MB model via the utility of nonlinear Kalman filtering (KF) algorithms. Subsequently, an enhanced neural metaheuristic Kalman filter (NMKF) is proposed that improves the estimation accuracy of the MB model parameters. The results demonstrate the efficacy of the proposed NMKF in comparison with previous studies.

Design of an artificial neural network and proportional‐integral‐derivative controller using particle swarm optimization for Boeing 747‐400 aircraft pitch control

AbstractThis paper presents the design of an artificial neural network (ANN) and proportional integral derivative (PID) controller using particle swarm optimization (PSO) for Boeing 747‐400 aircraft pitch control (APC). The combinations of disturbance, open loop unstable and nonlinear dynamics are major problems in a Boeing 747‐400 commercial aircraft. This paper investigates the control mechanism of pitch angle control of Boeing 747‐400 with small disturbance theory linearization methods and ANN based non‐linear controllers. A PID controller is tuned by PSO, whereas the PID is tuned by graphical user interface (GUI) when compared with an ANN controller. The controller for this system was designed using an ANN controller and PID tuned using a recent optimization technique such as the PSO method with integral square error (ISE) as an objective function. A comparative study of the time domain performances of the pitch control of the Boeing 747‐400 commercial aircraft was presented. The ANN controller outperformed the PID‐PSO and PID‐GUI controllers in terms of system performance, including rising time (tr), settling time (ts), percentage overshoot (percent OS), and steady state error, across various elevator deflection angles. Basically, the percentage overshoot and steady state error were 0% and 0 respectively, indicating that the ANN controller achieved an improvement of 100%. Various parameters were compared with the PID‐GUI, PID‐PSO, and ANN controllers for pitch control of the Boeing 747‐400 air craft. The ANN controller architecture comprises of two input neurons, two hidden layer neurons, and one output layer neuron. The simulation was performed using Matlab/Simulink. The results show that the PID‐PSO controller was improved by the ANN controller and the performance specifications of the aircraft obtained by the ANN controller were satisfactory.

Prabhakar fractional model for natural convection flow of kerosene oil based hybrid nanofluid containing ferric oxide and zinc oxide nanoparticles

Based on enhanced thermal performances of hybrid nanomaterials, various multidisciplinary applications of such hybrid nanofluids are presented in the cooling processes, HVAC systems, energy sectors, boosting the energy sources, automotive thermal systems etc. Owing to such motivated applications in mind, different mathematical models are developed. However, the thermal analysis for hybrid nanofluid with help of fractional models is not focused properly. Therefore, the objective of current research is to develop a mathematical model for enhancement of heat transfer by using the hybrid nanofluid. The decomposition of zinc oxide (ZnO) and ferric oxide (Fe3O4) with kerosene oil base fluid is used for identifying the thermal reflection of hybrid nanofluid. The motivations to improve the thermal prospective of kerosene oil is due to its importance in the energy sources as a fuel and industrial applications like solvent, degreaser and operation of air craft. The vertical moving surface is used to initiates the flow. The natural convective flow is further perturbed with applications of mixed convection effects. The evaluation for heat transfer is inspected by incorporating the external heat source. The mathematical modelling of problem is presented via fractional expressions. The Prabhakar scheme is used to develop the analytical expressions. The accuracy of implemented scheme is inspected by comparing the numerical data computed via Zakian, Stehfest and Tzou's algorithms. The significance of problem is visualized in view of involved parameters like fractional parameters, nanoparticles volume fraction, Grashof number and Prandtl number. The results claim that the enhancement in heat transfer due to decomposition of zinc oxide and ferric oxide nanoparticles is more exclusive as compared to simple nanofluid. The heat transfer enhanced due to nanoparticles volume fraction.

Experimental simulation of the generation of microwave radiation during the interaction of a lightning discharge with an aircraft

On a specialized testing installation — a high-voltage Marx generator, which allows the formation of a spark discharge up to 20 meters long, the process of the impact of lightning radio emission in the microwave range on an aircraft (AC) is simulated. A metal AC model made on a scale of 1:50 was placed in a 9 m long rod-plane spark gap. A positive voltage pulse was applied to the high-voltage electrode from the generator (front 100 μsec, duration 7500 μsec). The generated spark discharge passed through the AC model. It was found that when the spark channel passes through the body of the model, electromagnetic pulses of the microwave range with a duration of less than 500 psec and a rise time of less than 100 psec arise. The measurement of the resulting microwave pulses was carried out using special radio equipment in the subnanosecond range. High-speed photography of the discharge development, carried out synchronously with electromagnetic measurements, showed that microwave pulses (up to 10 GHz) arise at the stage of development of the spark discharge leader in the part of the “high-voltage electrode – insulated model” gap. Such pulses can be considered as a factor dangerous for various AC microwave radio systems, when the AC is struck by lightning, as well as for other objects, including power facilities, which contain equipment with microelectronics. Such microwave pulses can also occur during nearby lightning discharges (for example, in a lightning rod of a power substation), when a powerful streamer corona occurs on devices and wires of ultra-high voltage lines), and when a high-voltage spark discharge occurs when switching equipment (disconnectors, arresters) is triggered. In this case, disruptions are possible in the operation of control equipment (for example, relay protection devices) that contains microelectronics, as well as various communication means available at electric power facilities operating in the microwave range (above 1 GHz).

Electrical engineering equipment for generating and measuring of complete pulse current of artificial lightning in the conditions of high-voltage electrophysics laboratory

Goal. Decision of problem scientific and technical task on the reliable generating and measuring in the conditions of high-voltage electrophysics laboratory basic component of complete pulse current of artificial lightning with the rationed amplitude-temporal parameters (ATPs) with the use of the modernized generator of current of lightning of type of UITOM-1. Methodology. Bases of the applied electrical engineering, electrodynamics and electrophysics, electrophysics bases of technique of high-voltage and high pulse currents, bases of high-voltage pulse technique and measuring technique. Results. Information, which specify on a decision at Research and Design Institute «Molniya» of National Technical University «Kharkiv Polytechnic Institute» problem scientific and technical task, related to the reliable generating and measuring in the conditions of high-voltage electrophysics laboratory of complete pulse current of artificial lightning, which contains pulse A- (repeated pulse D-), intermediate B- and long-term C- (shortened long C*-) components of this current, is resulted, ATPs which answer the hard technical requirements of normative documents of the USA of SAE ARP 5412: 2013, SAE ARP 5414: 2013 and SAE ARP 5416: 2013. Short information is indicated about the applied electrical circuits of separate high-voltage generators of pulse currents of condenser type of GIC-A (GIC-D), GIC-B and GIC-C (GIC-C*), which it is worked as synchronous appearance on the general electrical loading in composition the modernized powerful high voltage generator of complete pulse e current of artificial lightning of type of UITOM-1, and in-use high-voltage measuring facilities which contain the heavy-current low-resistance shunts of type of SHK-300 for simultaneous registration with their help on examinee on stability to lightning devices objects of aviation and space-rocket technique of ATPs proper component of complete i pulse current of artificial lightning. Technical examples are resulted and the row of results of practical application of the indicated domestic powerful high-voltage proof-of-concept electrophysics equipment is described at the tests of elements of some aircrafts (ACs) on resistibility to the direct action on them of complete pulse current of artificial lightning with rationed ATPs. Originality. A problem is formulated and having the important applied value in area of aviation and space-rocket technique for the leading countries of the world scientific and technical task on the reliable generating and measuring in the conditions of high-voltage electrophysics laboratory indicated component of complete pulse current of artificial lightning with rationed ATPs and concrete electro-technological ways and hardware are indicated for its successful decision. Practical value. The use of the modernized powerful high-voltage generator of complete pulse current of artificial lightning of type of UITOM-1 developed in practice and created in Ukraine will allow to conduct the real verification on resistibility to the action of lightning of different side systems, devices and construction elements, containing metallic and composition materials, both again developed and modernized ACs, that will be instrumental in the increase of vitality of such ACs in the extreme terms of their flight and stay in an electrical active earthly atmosphere with flowing in it storm electrical discharges. References 30, tables 3, figures 20.

Analysis of mechanical properties and free vibrational characteristics of novel Grewia optiva/basalt fiber reinforced hybrid polymer composites

AbstractThis study emphasize on the fabrication and testing of Grewia optiva/Basalt fiber reinforced polymer composites for use in internal applications of automobiles and aircraft. The study investigates the use of Grewia optiva fiber (local plant based fiber) with Basalt fiber, where chopped Basalt fiber (6, 9, and 12 mm) is reinforced in polyester matrix in combination with Grewia optiva fiber. Composite test specimen are fabricated and analyzed using a smart actuation system to evaluate the free vibrational behavior of the composites experimentally. The impact of various parameters including length of the fiber and its weight percentage on the free vibrational behavior of composites is determined. The percentage of individual reinforced fiber is varied (0, 4, 8, and 12 wt.%) maintaining fiber weight % constant, that is, 12 wt.% of composite. The experimental results help to identify the variations in natural frequencies of Basalt/Grewia optiva fiber based composites. B12/GO0 demonstrate the natural frequency of 67 Hz and 44.71 MPa tensile strength for 12 mm fiber reinforced composites. The finding from this experimental work provide insights into the potential applications of Basalt/Grewia optiva fiber reinforced composites for automobile and air craft industries.

ПРИМЕНЕНИЕ МЕТОДОВ ТЕОРИИ ВАЖНОСТИ КРИТЕРИЕВ ДЛЯ ОПРЕДЕЛЕНИЯ ОПТИМАЛЬНЫХ ВИДОВ ДЕЯТЕЛЬНОСТИ ПРИ УПРАВЛЕНИИ ВОЗДУШНЫМ СУДНОМ

The formalization of the activities of pilots in the controlling of the latest generation aircraft (AC) is experiencing difficulties due to significant changes in the structure of human activity - the operator. For the most complete analysis of the procedure for controlling the activities of pilots when using various levels of automation, it turns out to be not enough to use only the mathematical apparatus of probability theory and decision-making methods in vague conditions. The article presents the result of applying the methods of the theory of the importance of criteria in order to determine the most rational choice of crew members' activity at various stages of flight and piloting modes of the latest generation aircraft.

The Berlin-Brandenburg Air Study-A Methodological Study Paper of a Natural Experiment Investigating Health Effects Related to Changes in Airport-Related Exposures.

Objectives: This paper presents the study design of the Berlin-Brandenburg Air study (BEAR-study). We measure air quality in Berlin and Brandenburg before and after the relocation of aircraft (AC) traffic from Tegel (TXL) airport to the new Berlin-Brandenburg airport (BER) and investigate the association of AC-related ultrafine particles (UFP) with health outcomes in schoolchildren. Methods: The BEAR-study is a natural experiment examining schoolchildren attending schools near TXL and BER airports, and in control areas (CA) away from both airports and associated air corridors. Each child undergoes repeated school-based health-examinations. Total particle number concentration (PNC) and meteorological parameters are continuously monitored. Submicrometer particle number size distribution, equivalent black carbon, and gas-phase pollutants are collected from long-term air quality monitoring stations. Daily source-specific UFP concentrations are modeled. We will analyze short-term effects of UFP on respiratory, cardiovascular, and neurocognitive outcomes, as well as medium and long-term effects on lung growth and cognitive development. Results: We examined 1,070 children (as of 30 November 2022) from 16 schools in Berlin and Brandenburg. Conclusion: The BEAR study increases the understanding of how AC-related UFP affect children's health.

Controlling the Process of Formation of the Scientific and Technological Background in Aircraft Construction Based on the Assessment of a Deficit of Functional Properties of Promising Aircraft

The existing experience of the design of aviation technology proves that in a number of cases a promising aircraft (AC) that satisfies the set of requirements cannot be created within the framework of the accumulated scientific and technical groundwork in the field of AC manufacturing. As a result, there is a need to determine priority scientific and technical solutions, whose implementation, under time and financial constraints, will ensure the creation of an AC that meets the stated requirements. It is shown that such a problem can be interpreted as a so-called generalized optimization problem, whose difference from the classical mathematical programming problem lies in the fact that the set of permissible values of flight performance characteristics (FPC) is an additional object of optimization. A constructive algorithm for solving such a problem is proposed, whose capabilities are illustrated using the example of designing a transport ramp aircraft

Expanding the Technological Possibilities of Multilayer Micro-Plasma Powder Deposition Process by Optimizing the Quality and Composition of Process Gases

Introduction. Mastering the micro-plasma powder deposition (MPWD) technology for refurbishing parts of nickel-based super alloy aircraft gas turbine engine (GTE) has been remaining a relevant task of the Ukrainian air craft industry for, at least, 15 last years.Problem Statement. MPWD or subsequent heat treatment of GTE parts made of nickel-based super alloy after long-term operating hours, with high γ'-phase content, might reveal increased cracking susceptibility. The search for ways to optimize the welding deposition technology has shown the necessity to scrutinize the positive technological effect of rational choice of the quality and content of process (shielding, plasma and transporting) gases.Purpose. To study the effect of process gas content on the heat source parameters, the conditions of the formation of deposited metal and its quality.Material and Methods. Comparative study of the micro-plasma (PPS04 plasmatron, UPNS-304M welding machine) and TIG (VSVU-315 power source) arc heat parameters depending on welding current and process gas has been conducted by the conventional flow calorimetry technology. Comparative estimation of the total work piece heat input parameters has been made based on the previously developed methodology with registering the welding current parameters based on m-DAQ14 analog-to-digital converter (ADC).Results. The comparative research during MPWD of sample parts has shown that the content and quality of process gases can significantly (up to 2.5 times) affect the amount of heat transferred into the work piece and, respectively, the possibility to provide the technological strength of “base-deposited metal” welded joint.Conclusions. The industrial MPWD process optimization by the criteria of work piece heat input parameters, technological strength of “base-deposited metal” welded joint and filler powder consumption,by means of increasing argon (plasma and transporting gas) quality by other gases impurities content and switch to 90% Ar + 10% Н2 argonhydrogen mixture shielding gas has been established to be promising and expedient way to solve the problem.

Development of Low Velocity Bullet Proof Vest

Bulletproof vest is a vest which can protect wearer’s body from the impact of bullet. Soft vests are made of many layers of woven are laminated fibers and can protect the wearer from small caliber, hand gun and shot gun projectiles.Fiber reinforced composite materials have become important engineering materials used such as marine bodies, air craft structures and light weight body armor for ballistic protection in military applications. Composite body armor is an item or piece of clothing that is designed to protect the wearer against a variety of attacks. The most useful properties of composites are high specific strength and specific stiffness, good corrosion resistance and good fatigue resistance. Advanced composite materials, typically consisting of reinforced fibers in a resin matrix.So that we have construct the composite using glass and sisal with resin matrix.

APPLICATION OF WIRELESS COMMUNICATION AND TECHNICAL VISION TECHNOLOGIES TO IMPROVE AVIATION SEARCH AND RESCUE OPERATIONS

The subject of research in the article is approaches to improving the onboard equipment of a search and rescue aircraft (AC). The purpose of the study is to develop proposals for improving the technical means of searching for aircraft that have suffered an accident, namely video surveillance systems and information transmission to the control centers (CC) of the search and rescue operation, based on the analysis of the Rules for Search and Rescue Support of Flights of the State Aviation of Ukraine and foreign experience in search and rescue operations. It is proposed to use a light multipurpose helicopter of the Mi-2 type as a search and rescue aircraft (SRAC). The work solves the following problems: studying modern approaches to ensuring aviation search and rescue operations; analyzing technical means of ensuring the search for crashed aircraft; developing proposals for a method of transmitting information from the airborne control center to the ground control center; selecting a suitable carrier for special equipment and individual samples of video surveillance and data transmission systems. The method of comparative analysis is used to solve partial problems. The following results have been obtained: the requirements for the search characteristics of SRAC are determined, in particular, it is proposed to use a light multipurpose helicopter as SRAC; a scheme for organizing communication with the search operation control center using wireless communication technologies is presented; specific requirements for individual components of SRAC onboard special equipment are formulated. Conclusions. The introduction of wireless communication technologies together with thermal imaging equipment will increase the speed and efficiency of searching for crashed aircraft, especially at night and in conditions of limited visibility (fog, smoke). In addition, the range of tasks of light helicopters such as the Mi-2 is expanding, and the number of both onboard and ground operators directly using thermal imaging equipment (infrared camera) to determine the location of the crash is increasing. In this case, the total number of personnel involved in search and rescue operations is not affected.

Partial differential equations modeling of bio-convective sutterby nanofluid flow through paraboloid surface

In this research article, the behavior of 2D non-Newtonian Sutterby nanofluid flow over the parabolic surface is discussed. In boundary region of surface buoyancy-driven flow occurred due to considerable temperature differences produced by the reaction happen between Sutterby nanofluid and catalyst at the surface. Free convection which is sighted easily on the parabolic surface is initiated by reaction on the catalyst surface modeled the 1st order activation energy. Applications of parabolic surfaces are upper cover of bullet, car bonnet, and air crafts. Under discussion flow is modelled mathematically by implementing law of conservation of microorganism’s concentration, momentum, mass and heat. The governing equations of the system is of the form of non-linear PDE’s. By the use of similarity transform, the governing PDE`s transformed as non-dimensional ODE’s. The resultant system of non-dimensional ODE’s are numerically solved by built-in function MATLAB package named as ‘bvp4c’. Graphical representation shows the influence of different parameters in the concentration, velocity, microorganisms and temperature profiles of the system. In temperature profile, we examined the impact of thermophoresis coefficient Nt (0.1, 0.5, 1.0), Prandtl number Pr (2.0, 3.0, 4.0), and Brownian motion variable Nb (0.1, 0.3, 0.5). Velocity profile depends on the non-dimensional parameters i.e. (Deborah number De & Hartmann number Ha) and found that these numbers (De, Ha) cause downfall in profile. Furthermore, mass transfer, skin friction, and heat transfer rates are numerically computed. The purpose of the study is to enumerate the significance of parabolic surfaces for the transport of heat and mass through the flow of bio-convective Sutterby nanofluid.

Information System of the Robotic Towing Airfield System

Relevance. The development of aviation technology is associated with the development of new means that directly ensure the movement of aircraft (AF) at the airfield. To carry out ground maneuvers with aircraft, towing airfield systems (UAS) are used, which can significantly reduce noise and air pollution near the airport, as well as reduce the inefficient resource consumption of aircraft engines and provide significant savings in aviation fuel. UAS is also used when the aircraft loses the ability to move and is located on or near the working area of the airfield, which creates a serious problem leading to the closure of the airport for flights, while airlines incur significant losses.Purpose of research. Improving the efficiency of the towing airfield system through the development of an information system. Objectives. Development of the structure of a robotic towing airfield system, drawing up a structural diagram of the ACS layout of the towing platform, design of block diagrams of the logical controller of the ACS platform.Methods. The level of horizontal deviation of the platform from the contrast line was chosen as the setting influence determining the position of the platform in space, which is measured by analyzing images coming from the technical vision system installed on the tow truck. Results. In the course of the study, the structure of a robotic towing airfield system was developed. Based on this structure, a block diagram of the ACS layout of the towing platform was designed and a block diagram of the logical controller of the ACS platform was developed.Conclusions. 1. The structure of a robotic towing airfield system has been developed, including a mobile tow truck, a coupling device, an aircraft, and an on-board control system. 2. An algorithm for controlling the positioning of a robotic towing airfield system based on the logical processing of signals of an optocoupler matrix has been developed. 3. Algorithms have been developed for controlling the movement of the RBAS along a given contrast line under the action of external disturbing influences of a deterministic and random type, allowing for high-precision movement of the RMB.

Investigation of the technology of the cooperation between the air traffic control and the ornithological service

This article analyzes the technology of cooperation between the air traffic control (ATC) and the ornithological service (OS). As part of the analysis, the procedures of preventive measures for air traffic controllers (ATC) and OS specialists to avert bird strikes were considered. The phases of aircraft (AC) taxiing to a runway (RW) and takeoff were considered. For individual flights, delays were determined. Flow charts and network technological charts of the ATC-OS cooperation were built. The direct air traffic management within the framework of this article is carried out by air traffic controllers of the control units «Ground» and «Tower». The flight director (FD), ground personnel and the OS specialist are also involved in the work. The technology of the ATC-OS cooperation is evaluated in terms of efficiency and flight safety. As an indicator of efficiency in this study, a value equal to the ratio of the expected time to the real time of AC departure was adopted. The time of movement, denoted in the flight plan, varies depending on an aerodrome, RW, TW, AC type and many other factors. Therefore, to determine the expected time of AC flight support, statistical data, indicating the AC flight time without the impact of external factors, were used. The study of the technology for the ATC-OS cooperation was carried out for 12 months. The research array was obtained from the daily flight plans of Zhukovsky airport – flight number, AC type, takeoff-landing time, various aircraft ground maneuvers at an airfield.

The automated system for reducing losses from evaporation and water contamination in jet fuel in the tanks of the refueling complex

In the process of the production activity of the airport refueling complex (RC), because of the movement of jet fuel associated with emptying and filling fuel tanks when receiving and supplying jet fuel for aircraft (AC) refueling, two negative phenomena are bound to occur – water contamination in jet fuel with when interacting with air, its evaporation and entrainment into the atmosphere. This entails economic losses, an increased level of fire and explosion hazard and environmental damage. The amount of damage caused by the natural loss of jet fuel, because of the inevitable emission of vapor-air mixture (VAM) from the RC tank farm, reaches 10...14% of the volume of jet fuel transshipment. In turn, such volume of evaporated kerosene leads to a serious environmental problem – pollution of the atmosphere by aviation fuel vapors, escalating the costs for compensation and taxation of environmental management, potential harming the health of the RC full-time staff. The RC becomes a fire-hazardous object, which incurs expenses for fire protection measures. The article evaluates the quantitative and qualitative losses from evaporation and water contamination in fuel in the conditions of storage, reception, and delivery of aviation fuel from the airport RC tanks. Based on the analysis of the mechanism of deterioration of the aviation fuel quality from water contamination and mechanical impurities, as well as losses of light fractions of aviation fuel caused by the phenomena of strong and inconsiderable breathing of tanks of the tank farm facilities, invariably accompanying the processes of storage, delivery, and reception of aviation fuel. The causes and mechanism of formation of aviation fuel losses from strong and inconsiderable breathing of tanks as well as from saturation of the gas space are established. The recommendations for reducing these losses are proposed. The article analyzes the known methods of reducing (preventing) VAM emissions and considers the task of developing reliable and automated methods and technologies for reducing jet fuel losses, particularly, reducing the level of water content in jet fuel. Automation of the processes to minimize jet fuel losses is becoming relevant. The calculation of jet fuel losses from evaporation during storage, reception, and delivery of jet fuel to the airport RC within the heavy air traffic period concerned with the greatest movement of jet fuel, giving an idea of the scale of economic losses and environmental damage, is presented. The currently existing systems for reducing losses of petroleum products are considered. The article presents a technical solution to reduce the loss of jet fuel from evaporation in tanks by developing an automated system that minimizes the level of water content in jet fuel in the tank and reduces the loss of light fractions of jet fuel during storage, reception, and delivery due to the dehumidification of atmospheric air entering the above-fuel space of the tank, as well as VAM condensation and separation under inconsiderable and strong breathing of tanks. The proposed system for reducing losses of aviation kerosene from evaporation will significantly increase the efficiency of capturing VAM of aviation fuel when stored in the RC fuel tank battery, improve the environmental situation of the RC activity, minimize the economic RC losses from natural loss, as well as mitigate the risk for fire hazard of the airport RC. The system is designed for retrofitting tanks for receiving, storing, and delivering jet fuel, fuel tank batteries, fuel, and lubricants warehouses.

The Study of the Lift Coefficient of NACA-0012 Airfoil Subjected to an Incompressible Media by Using the Cartesian Cut Cell Method

In order to shorten product design time, engineers need to create high quality meshes within a few days or hours. Newer automated techniques have been published to tackle this need, the Cartesian Cut Cell is one of them. This study is focused on the effect of different Cut Cell meshing strategies on the accuracy of aerodynamic performance predictions. The method can be described as a methodology in which Cut Cells are applied to the geometry utilizing a process involving rectangular/hexagonal cells on a regular lattice cutting through the geometry. The Cut Cell meshing is a general purpose designed for ANSYS FLUENT, making use of Workbench to construct the airfoil shape and the mesh. The results obtained for NACA-0012 are computed using two models available in ANSYS FLUENT, namely the Eq. 2 k-ω SST and the Eq. 3 k-kl-ω models. The three-dimensional numerical simulations were created for steady incompressible flow around NACA-0012 shape. Lift coefficient, Boundary layer thickness, mesh expansion ratio, and mesh density variation parameters were investigated. For this application both models produce good lift results. k-kl-ω produce better lift and the results are close to the measured data. The Cut Cell method showed a very good agreement between Computational Fluid Dynamics results and experimental data. This work illustrated that the Cartesian Cut Cell method has the ability to generate high quality mesh, which captures the details of the viscous boundary layer easily. The future work is to use more sophisticated turbulence models and mesh refinement for air craft wing with flap.

On the issue of technical compatibility of electrotechnical complexes and systems of aircrafts

BACKGROUND: Among the variety of different types of technical compatibility (TC), design, technological, operational and thermal types have a high priority. The reason is that these TC types are commonly the most problematic and typical for the majority of modern machines.
 AIMS: Two approaches to development of new prospective projects of autonomous electrotechnical complexes (ETC) of aircrafts, such as particular system design (PSD) and complex system design (CSD) are considered.
 METHODS: Analysis and synthesis of elements of the ETC of aircraft, as well as a systematic approach to design.
 RESULTS: Details and advantages of the CSD are revealed. Problems and conditions, making practical implementation of this approach possible, are given. All notions and considered design approaches find their application in development and modernization of aircrafts (AC) as well as ETCs. Various types of compatibility, such as operational compatibility, design compatibility, thermal compatibility, size compatibility, energetic compatibility and informational compatibility are outlined. Generally, TC research by engineers and scientists gains more relevance of solving the problem of modern machines improvement. Scale and relevance of this problem only at focal points of ensuring some TC types are given in the article, as more detailed consideration is problematic even at a monograph level and impossible at an article level because the number of researched TC types goes beyond 40.
 CONCLUSIONS: For the complete analysis of thermal mode of the whole AC, it is necessary to have the equation system consisting of the equation for the aircraft as a whole and equations for all onboard elements. Such equation system becomes extremely bulky even for small ACs. Therefore, approximate methods of analysis and calculation are commonly used. The most spread approximate method is consideration of only steady-state thermal processes for various AC operational modes. Final target of this approach is to obtain sufficient quantity of thermal modes points, enough to approximate the whole thermal mode of an aircraft.

Моделирование полета беспилотного летательного аппарата в Matlab Simulink

In this article, a simulation model of an unmanned aerial vehicle in Matlab Simulink has been developed. To build a simulation model, a mathematical description of the equations of motion of an aircraft (AC) is performed: kinematic and dynamic models with six degrees of freedom and twelve state variables, and a mathematical description of external forces acting on the aircraft is also performed. The simulation model includes several blocks that interact with each other to ensure the operation of the unmanned aerial vehicle: the air craft dynamics unit, which is responsible for simulating the movement of the aircraft in three dimensions, the autopilot unit, which simulates the operation of the aircraft navigation system and provides stabilization in the air, the control unit engines, which regulates the speed of rotation of the engines depending on the control signals, an external environment block that simulates the air environment in which the aircraft moves. The main advantage of the constructed model is the ability to change the parameters of the aircraft interactively and evaluate the main parameters using graphs. The correctness of the autopilot operation is confirmed by the graphs of transient processes along the three axes of the aircraft: roll, pitch, yaw. In the future, based on the constructed model, it is possible to create a fully automatic obstacle avoidance system that will allow the unmanned aerial vehicle to safely move from the start to the end point, taking into account all the obstacles in the flight path. Thus, the simulation model of an unmanned aerial vehicle based on Simulink makes it possible to evaluate the operation of the autopilot and other aircraft systems with high accuracy and detail. Its use can be useful in the design and testing of new unmanned aerial vehicles.

Features of aircraft operation in tropical climate conditions

The paper considers the issues of climatic resistance of materials and means of protecting aircraft (AC). It has been established that the solution of these issues is at the intersection of several sciences, primarily applied climatology, materials science and the science of the reliability of complex technical systems. Particular attention is paid to the consideration of corrosion processes that aircraft are exposed to in the humid tropics and subtropics (India, Venezuela, Cuba, Indonesia, Vietnam, etc.), which is due to the intensive operation of Soviet and Russian-made aircraft in these regions.