Real Operating Conditions Research Articles

Numerical simulation of an external ballistic problem using analytical approach and atmosphere flow visualization by finite element method

Purpose. Analysis of the dynamic characteristics of the cargo in the presence of the speed of its carrier, taking into account the influence of the external environment and the determination of factors that affect the operational characteristics and parameters for the dynamic system control. Methodology. An approximate analytical approach to solving the nonlinear problem of external ballistics of a system with time-dependent parameters, which is implemented using the asymptotic perturbation method, and a numerical algorithm for modeling a dynamic process using a 3D software complex and the finite element method, which allows to visualize the nature of the flow around the object under wind load conditions. Findings. An analytical approach to solving the nonlinear problem of external ballistics of a system with time-varying parameters is proposed, as well as a numerical model, solution and visualization of a dynamic process that can be applied in problems of mathematical physics and engineering calculations. Originality. The use of an approximate analytical approach to solving the nonlinear problem of external ballistics, which includes a system of time-varying parameters, is a significant innovative step. For the first time, a three-dimensional distribution of the free fall parameters under atmospheric conditions was obtained depending on the time of free fall under the condition of an initial velocity different from zero. Obtaining the characteristics of the distribution, taking into account the aerodynamic quality of the object, made it possible to adapt the methods of analytical mechanics and differential equations with variable coefficients to the solution of the applied problem. The obtained characteristic three-dimensional surface allows to perform a study of the aerodynamic quality of the object under study using numerical methods and to visualize dynamic processes in three-dimensional space in order to obtain a qualitative picture of the perturbation of the object by the air flow. This integrated approach to the study of ballistic characteristics of cargo forms the scientific principle to perform engineering calculations to solve the problem of controlling dynamic systems. Practical value. An approximate analytical approach and a calculation model of the dynamic process of a mechatronic unmanned system make it possible to increase its efficiency in the presence of an initial speed and ensure the accuracy of the application of ballistic cargo delivery systems in real operating conditions.

A bilinear interpolation model for estimating commercial vehicles' fuel consumption and exhaust emissions

In this paper, an estimation model based on bilinear interpolation of data from the EMEP/EEA air pollutant emission inventory guidebook database regarding fuel consumption and exhaust emissions of commercial vehicles in different operating conditions is developed. Depending on vehicle's average speed, road slope and load factor, the model determines the fuel consumption and emissions for the observed vehicle type, category and emission standard. In order to validate the model, recordings on actual commercial vehicles were made in real operating conditions on two urban public transport bus lines in Belgrade. Comparison of the estimated and actual results from vehicle operation substantiate satisfactory validation of the model, making it suitable for logistics managers in operational and tactical planning as easy to use decision making tool allowing better sustainability and lower environmental footprint.

Charging characteristics of long distance accumulator for underwater electro-hydraulic control system.

Long distance accumulators are widely used in underwater electro-hydraulic control systems. However, as the working depth increases, the underwater umbilical cable becomes longer. The actual physical properties of the gas in the accumulator change. These factors affect the charging characteristics of the accumulator. To address the above issues, a simulation model of the charging of the long distance accumulator under real operating conditions is developed. Among them, the real properties of the gas inside the accumulator were calculated using the Redlich-Kwong-Soave method. The coefficient of friction within the umbilical cable is based on the Reynolds number and relative roughness. The simulation data were compared with the experimental results in the South China Sea to verify the accuracy of the simulation model. The effects of key factors on the charging characteristics of the long distance accumulators were also analyzed. The results show that the simulation results are in good agreement with the experimental results. The law of accumulator charging was analyzed: the greater the pressure of the gas source, the smaller the accumulator charging time; the greater the working water depth, the shorter the accumulator charging time. The research provides guidance for the design of long distance accumulators.

Experimental Study of Vibrations of Agrodrone Propeller-Motor Group

The problem of experimental research of the parameters of the propeller-motor group of an unmanned aerial vehicle (agrodrone) is considered. An analysis of the work performed by agrodrones in agriculture, as well as popular serial models of agrodrones produced by well-known global companies, including in the Republic of Belarus, has been carried out. A description of the design of the experimental stand, specially designed for testing the operation of the agrodrone power plant under conditions as close as possible to the real operating conditions in which the agrodrone has to operate, is given. The main structural elements of the test bench and measuring instruments that are used to conduct experimental studies of the operation of the propeller and its electric drive are described. The results of the research are presented in the form of quantitative values of the vibration parameters of the propeller-motor group of the agrodrone at given values of the input parameters of the electric drive control system, taking into account the influence of external factors. It is shown that the values of the parameters characterizing the vibrations of the propeller-motor group of the agrodrone can be different depending on the operating modes of the engines and changes in external conditions. Based on the results obtained, it was concluded that when formulating the mathematical formulation of the modeling problem, it is necessary to take into account the influence of random factors on the control system of the agrodrone, including vibrations caused by the operation of the agrodrone engines.

Theoretical and experimental evaluation of electric coolant pump benefits in real driving cycles

Engine thermal management is a promising option to reduce fuel consumption and harmful emissions of Internal Combustion Engines. This is particularly suitable to support the transition towards a carbon-neutral transportation sector, considering that the role of combustion engines is expected to persist in the near and medium future. In this study, a prototype pump electrically actuated was compared to a mechanical pump of a downsized gasoline engine that propels a real vehicle. In the first phase of the analysis, the cooling circuit was tested from a hydraulic point of view on all its branches using an engine mounted on a bench equal to that working on the vehicle. The hydraulic circuit was fully characterized via pressure transducers and flow meters in all branches for different thermostat lifts, representing different coolant temperatures. On the same bench, the OEM pump and an electrically actuated one, suitably redesigned on an operating point more representative of the real operating conditions, were tested. A vehicle propelled with the same tested engine (having a conventional mechanically actuated pump) was run on the road following three different driving cycles. The engine revolution speeds were registered, as well as the temperature of the cooling fluid. The electric and mechanical pumps were compared using the performance maps previously obtained. The electric pump speed was set to deliver the same coolant flow rate as the OEM pump, following the same sequence of thermostat lifts. The results show that a 60 % average reduction of the pump energy consumption is possible, leading to an average specific CO2 emission reduction of 1 g/km. This result is even more relevant during urban driving, with emission savings hitting 2.5 g/km.

Assessment of the DDES-γ Model for the Simulation of a Highly Loaded Turbine Cascade

Abstract The flow over the linear low-pressure turbine cascade MTU-T161 at Re = 90,000 is analyzed using delayed detached eddy simulations (DDES). At this operating point, the low Reynolds number and the high loading of the blade result in a separation bubble and a separation-induced transition of the flow over the suction side. The utilized DDES method is based on a vorticity-based formulation to calculate the subgrid length scales, and it incorporates the one-equation γ-transition model. The computational model of the MTU-T161 cascade consists of one blade passage, including the diverging viscous sidewalls. To reproduce realistic operating conditions and to mimic the experiments, synthetic turbulence is prescribed at the inlet of the computational domain. Several studies are performed to assess the accuracy and performance of the DDES one-equation γ-transition model against experimental data and a benchmark large eddy simulations (LES). The primary focus is on the prediction of the separation and the separation-induced transition mechanism. First of all, a systematic grid convergence study is conducted and grid criteria are derived in order to ensure a satisfactory agreement of the flow metrics, such as isentropic Mach number, friction coefficient distribution, and total pressure wake losses at mid-span with experimental data. Furthermore, a detailed analysis of the DDES model parameters, such as shielding function and subgrid length scale, is presented and the effect of these parameters on the prediction accuracy of the separation bubble region is analyzed. The analysis of the suction side boundary layer indicates that the turbulent kinetic energy should be resolved and modeled properly in order to represent the separation bubble correctly. In particular, the correct prediction of the separated shear layer above the separation bubble is of utmost importance. The results of the simulations reveal higher demands on grid resolution for such transitional flows than typically have been reported in the literature for turbulent boundary layers. This higher demand on grid resolution results in more expensive simulations than Reynolds-averaged Navier–Stokes (RANS). Nevertheless, DDES requires less computing time than wall-resolved LES. Additionally, the results of the transitional DDES model are compared to DDES without a transition model, an RANS eddy viscosity model, and a reference LES. The results show that the DDES approach needs to be coupled with a transition model, such as the one-equation γ-transition model, in order to capture the flow topology over a highly loaded turbine blade correctly. The benefit of the DDES one-equation γ-transition model becomes particularly evident when predicting the separated shear layer, the transition process, and the subsequent reattachment. The RANS eddy viscosity turbulence and transition models applied within our study are not able to predict the aforementioned mechanisms accurately. For highly loaded turbine blades in particular, the accurate prediction of flow separation and potential reattachment is crucial for the aerodynamic design of turbines, since large parts of the total pressure loss are generated in the separated region. For this reason, the DDES one-equation γ-transition model can be a good compromise in terms of predictive accuracy and computational costs.

Bioactivity of Allium sativum essential oil-based nano-emulsion against Planococcus citri and its predator Cryptolaemus montrouzieri

Botanical extracts, in particular essential oils (EOs), could be the ideal candidates for the development of biopesticides as an alternative to synthetic pesticides. However, some limitations of EOs (high flammability, volatility, degradability, poor solubility in water) prevent their use under real operational conditions. Nanotechnologies are useful tools to overcome the above-mentioned limitations of these natural substances. Furthermore, encapsulation in nano-delivery systems (nanoparticles and nano-emulsions) can improve the functional properties of EOs. In this context, this study aimed to develop a highly stable, concentrated garlic nano-emulsion (15%) and to evaluate the acute toxicity with different exposure routes towards Planococcus citri and its predator Cryptolaemus montrouzieri. First, garlic EO was used to develop a nano-emulsion (15% EO; 5% Tween 80; 80% water) using a high-pressure microfluidizer; then both the crude EO and EO in nano-emulsion were chemically investigated by Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS) technique. The nano-emulsion was physically characterized by dynamic light scattering analysis over time (24 h, 3 months and 1 year after preparation) and used in bioassays involving both the target and non-target organisms. Results showed that the garlic EO consisted of over 95% sulphur compounds with diallyl disulphide as the most abundant component, and the developed nano-emulsion remained stable even after 1 year, with droplets’ dimension within the nanometric range (221.4 nm). The nano-formulation was effective against the target pest after 48 h from the treatment (Direct: LC90 = 0.967%; Indirect: LC90 = 1.088%), while it had no effect on C. montrouzieri. These promising results highlight the potential of garlic-based nano-emulsion as effective and environmentally friendly insecticide for pest control.

ANN based-model for estimating the boron permeability coefficient as boric acid in SWRO desalination plants using ensemble-based machine learning

This study examines the relationship between input conditions and the prediction of boron rejection in full-scale seawater reverse osmosis (SWRO) desalination plants using ensemble-based machine learning. While reverse osmosis is the dominant desalination technology, limited research has focused on analyzing plant performance under actual operating conditions. To address this gap, we developed and implemented machine learning algorithms to forecast boron permeability coefficient values, which are indicative of boron rejection concentrations in the permeate. Our analysis utilizes data from a SWRO desalination plant in southeast Spain, examining various input variables and their influence on the prediction of these parameters. The results demonstrate that our ensemble-based machine learning approach can predict boron permeability coefficient values with a reasonable margin of error of 1 mgL−1, as evidenced by mean average error (MAE) and mean absolute percentage error (MAPE) values of 7.93·10–8 and 11.8 %, respectively. In conclusion, an innovative application of artificial intelligence algorithms in the field of water purification under real operational conditions has been introduced, thus introducing valuable insights into the use of machine learning algorithms for forecasting boron rejection concentrations in full-scale SWRO desalination plants. The findings lay the foundation for future researches exploring automated and deep-learning methods in water purification.

Evaluation of the bifaciality coefficient of bifacial photovoltaic modules under real operating conditions

Among the parameters that define a bifacial photovoltaic module, the bifaciality coefficients indicate the rear and front side ratio of the most representative IV curve points of a photovoltaic panel, that is, Isc, Voc and Pm. However, these parameters are defined under the ideal Standard Test Conditions (STC). Therefore, to provide a realistic insight regarding the performance of bifacial modules, it is necessary to evaluate these coefficients under real operating conditions. For such purpose, an outdoor campaign was performed to experimentally measure the maximum power bifaciality coefficient of two modified bifacial modules that resemble a rear and a front monofacial panel respectively. As a first result, if the measurements are translated to STC, using a linear approximation, the bifaciality matches the value indicated by the manufacturer. Additionally, the operating bifaciality coefficient shows a linear decrease trend, proportional to the irradiance level decrease. This result implies that on cloudy days, the average bifaciality factor is below the corresponding one from sunny days. Finally, for irradiances below 200 W/m2, there is a non-linear increase in the bifaciality, with greater values than the corresponding to the ideal STC conditions, which presumably are caused by the non-linearity performance of photovoltaic modules at low irradiances.

Examining the Optimal Use of WBG Devices in Induction Cookers

Modern induction cookers have started to demand challenging features such as slim design, high power ratings, high performance, and silence. All those requirements are directly related to the power semiconductors used in power converters. Si (silicon)-based power semiconductors are not capable of answering those demands because of strict operating conditions, such as high ambient temperatures. Therefore, WBG (Wide Band Gap) power semiconductors have been getting attention. In this study, WBG power semiconductors will be compared with Si-based IGBT (Insulated Gate Bipolar Transistor) under different operating conditions. The best option to use WBG power semiconductors in modern induction cookers will be analyzed. The performance of a series-resonant half-bridge converter was evaluated under various operating conditions. Measurements were obtained from the real operating conditions of induction hobs. The switching frequency is changed from 20 kHz to 100 kHz, while the power rating is increased to 3.7 kW. In addition to traditional 4-zone induction cooktops, this discussion also provides a comprehensive analysis of high-segment, fully flexible induction cooktops. While the IGBT-based design exhibits 25.79 W power loss per device, the WBG device exhibits 6.87 W in the maximum power condition of conventional induction cooker operation. When it comes to high-frequency operation, the WBG power device exhibits 10.05 W at 95 kHz. Total power loss is still well below that of the IGBT-based conventional design. Appropriate usage of WBG power semiconductors in modern induction cookers can exploit many more benefits than Si-based designs.

CFD study of flameless combustion in a real industrial reheating furnace considering different H[formula omitted]/NG blends as fuel

On the path towards decarbonisation of the steel industry, the use of H2/NG blends in furnaces, where high temperatures are needed, is one of the alternatives that needs to be carefully studied. The present paper shows the CFD study carried out for a full-scale reheating furnace burner case. The real operating conditions as well as experimental measurements provided by the furnace operator were used to validate the results and reduce simulation uncertainties. The burner under consideration (2.5 MW) works in flameless mode with natural gas and preheated air (813 K). Starting from this point, another three fuel blends with volumetric percentages of 23% (also known as G222), 50% and 75% of H2 in natural gas were considered. For this purpose, the open source CFD code OpenFOAM was used, where the novel NE-EDC turbulence-chemistry interaction model was implemented, which has already been successfully validated specifically for flameless combustion in a furnace. The implementation incorporated an enhanced approach for calculating the chemical time-scale, coupled with a specific post-processing solver to predict NOx emissions. The study analyses the relative impact of the considered fuel blends on NOx formation and flameless regime. The modelling results demonstrated the burner’s capability to operate efficiently with high concentrations of hydrogen, maintaining flameless regime in all cases. This condition ensured uniform temperature distributions and low levels of NOx emissions, reaching a maximum value of 86 mg/m3. These results indicated the proper functionality of the existing natural gas-based burner with H2/NG blends, which was the primary requirement for the conversion process.

Evaluating energy generation of a building-integrated organic photovoltaic vertical façade: A case study of Latin America's pioneering installation

Building-integrated photovoltaics play a key role in the reduction of greenhouse gases emission towards sustainability in the building and construction sector. Organic solar technology holds several advantages such as lightweight, flexibility and semitransparency, suiting well for this type of application. When integrated into windows and facades, it provides a dual benefit: it acts as a solar radiation barrier, improving indoor thermal comfort, while also generating off-grid power. Besides that, organic devices are known to be more efficient than traditional photovoltaics based in silicon in diffuse and low light conditions. Nevertheless, only a few studies have been conducted in the area employing large-area commercial modules, in real operational conditions and for a long-term period. This work has the purpose of reducing this gap and shine a light on this debate bringing an analysis based on real data of a set of organic panels laminated in glass in a vertical pioneer installation in Latin America. For this, several linear regression models were tested to predict the energy generation from meteorological data and solar position throughout four years of operation, and the best models developed achieved 0.76 and 0.81 values for R2 with validation data, respectively for simple and multiple regressions. A visual analysis showed that the OPV system produced more energy in winter due to lower solar altitude, despite lower global radiation levels. The most significant variables in the models were the global solar radiation and the solar altitude. The use of glass lamination and vertical orientation likely preserved the performance of the panels, keeping energy generation consistent over four years, akin to the first year.

Numerical evaluation of doubly clamped self-adaptive fins acting as vortex generators inside micro heat sinks (MHS)

The continuous increase in the power density of integrated circuits (ICs) has placed thermal management as a key focus for the ICT community. Current liquid cooling systems are usually not optimized for the real operating conditions of advanced electronics, which have heat loads that can vary in time and space. Hence, conventional cooling devices lead to non-uniform temperature patterns at the package level and overcooled systems. This work proposes the use of thermally adaptive actuators, based on doubly clamped fins able to change its shape with temperature, to improve the performance of micro heat sinks with an optimized adaptation to temporal and spatially variable thermal parameters. The effect of this thermally responsive bistable fins on the efficiency of two different micro heat sinks (MHS), one based on microchannels and other on a matrix of microfluidic cells, is numerically evaluated. Results demonstrated a maximum heat transfer enhancement of 40% when adding the clamped-clamped fins within a microchannel and 20% when the fins were placed inside a microfluidic cell. Additionally, savings on hydraulic pumping power have been quantified between 8% and 11%.

Coupled Thermo-Structural analysis of absorber tube for direct steam generation in parabolic trough solar collector

The absorber tube is a key component of a parabolic trough solar collector, and the bending of the absorber has an important role in receiver failures. The detailed survey of existing commercial solar power plants reveals that 55 % of failures happened due to the rupture of glass envelope and 29 % due to the loss in annulus vacuum. In this study, coupled thermal–hydraulic and structural stability analyses have been performed to understand the thermo-structural performance of absorber tubes under realistic operating conditions of direct steam generation processes. The fluid flow and heat transfer equations have been solved using the FVM scheme, and structural equations have been solved using the FEM scheme. The impacts of absorber material selection have been studied using steel absorbers and copper-steel bimetallic absorbers. The study has been performed for operating pressure of 60 bar and 100 bar, mass flow rates of 0.4 kg/s and 0.6 kg/s, and DNI of 750 W/m2. The temperature gradient, deflection, strain, and stress in the absorber wall have been analyzed. It has been observed that the temperature gradient in the absorber could be reduced by 51 % and deflection by 40 % using a copper-steel bimetallic absorber instead of the steel absorber. The maximum thermal strain observed under the subjected boundary condition in the steel absorber is 6.27 mm/m, and in the bimetallic absorber is 6.06 mm/m. Further, the maximum equivalent stress of 31.1 MPa in the steel absorber and 39.8 MPa in the bimetallic absorber has been observed. The present work is useful for understanding the absorber's thermo-structural functionality in the preheating, evaporation, and superheating stages of direct steam generation in solar collectors.

Hybrid storage system management for hybrid electric vehicles under real operating conditions

This study proposes the use and management of hybrid storage systems to power hybrid electric vehicles with the aim of reducing the negative effects of high current values on battery cycling life. Findings derive from a case study on a commercial plug-in hybrid electric vehicle with battery pack operations supported by a Lithium-ion Capacitor module. Specific experimental laboratory activities focused on the parametrization and validation of an equivalent circuit model representing the behavior of Lithium-ion capacitors for integration into the overall vehicle model (designed calibrated and validated on the basis of data from on-board data acquisition and measurement systems). The simulation platform was used to test various energy management strategies for the hybrid storage system supplying the vehicle during real driving cycles characterized by different operating conditions and driving styles. Results highlight the benefits of using the considered management strategies in terms of battery durability, allowing performance comparison for different driving routes and styles.

Modeling of a power consumption by bus in the real operating conditions

In spite of numerous researches concerning a power consumption by the vehicles, during everyday operation there are the significant deviations from the consumptions indicated by the factories-manufacturers. It is caused by a great number of different factors, the main part of which take the operating conditions. In order to determine the power consumption of a vehicle in real operating conditions, it is necessary to solve a difficult problem with many unknowns. While making the investigations, the authors have used a multi-criteria approach that takes into consideration the guided, unguided and conditionally guided factors that influence the vehicles power consumption. The in research work approach provides a modeling of a power consumption by the vehicles with a simultaneous changeability of factors in the determined limits. The researches were made on a base of Т70110 trolleybus. There was made an investigation of influence of every factor on a power consumption, in addition to that there were made 7000 simulations, on the base of which, using a law of large numbers, there were found the corresponding changeability ranges. During the researches there were made 122 simulations of a power consumption, as a result of which there was determined an area of values of a power consumption.The obtained theoretical results are very well correlated with the experimental data, and a deviation is equal to 3…6 % for normal operating conditions. A comparison of the received data of a power consumption with the researches results, obtained by another researchers, also shows a great convergence.

Steady-state modelling of PEM fuel cell for evaluation of performance.

The influence of operating variables like temperature, pressure, humidity etc. needs to be reduced to optimize the performance of proton exchange membrane fuel cells (PEMFCs). A model that can accurately simulate the real operating conditions of a fuel cell can be used to optimize its performance. This paper develops and simulates a mathematical model for PEMFC in steady-state operating conditions. A steady state model is built in MATLAB-Simulink environment. The effects of different operating variables on the performance of the PEMFC have been studied. The parameters include operating temperature and reactant flow pressure. The results in the form of polarization curve, efficiency, power and current density have been analysed to compare the fuel cell behaviours. The results show good conformity with other existing models.

Numerical research on kerosene/hydrogen/air rotating detonation engines with discrete injection strategies

The two-dimensional simulation of two-phase rotating detonation engines commonly adopts the nozzle–wall configuration, which is inconsistent with the real configurations in experiments. In the annular slot–nozzle structure, the oxidant is completely injected into the annular gap, whereas the fuel is partially injected into the nozzle hole, which is closer to the real operation condition. In this study, a gas–liquid two-dimensional numerical investigation was conducted to explore a more accurate operating condition with a discrete injection configuration. The effects of the kerosene/hydrogen injection area ratio and hydrogen equivalence ratio on the propagation mode and operating performance were investigated. The simulation results show that the kerosene droplet/hydrogen/air gas–liquid two-phase rotating detonation wave exhibits different propagation modes depending on the hydrogen equivalence ratio. When the hydrogen equivalence ratio (φH2) is 0, the detonation wave cannot be successfully initiated. When φH2 is increased to 0.2 and 0.5, a single-wave propagation mode is generated. When φH2 is 1, a double-wave propagation mode is produced initially in the combustion chamber and is subsequently converted into the deflagration mode. The flow field structure, velocity performance, and propulsive performance in the detonation combustion chamber are analyzed. It was found that an appropriate amount of hydrogen addition to the liquid kerosene detonation can aid in stabilizing the propagation of the detonation wave and improving the performance of the detonation engine.

MODELING OF INTELIGENT SOFTWARE FOR THE DIAGNOSIS AND MONITORING OF SHIP POWER PLANT COMPONENTS USING MARKOV CHAINS

The reliability and serviceability of metal structures depends on the quality of control over the technical condition and mechanical properties of materials in accordance with international standards. However, in the course of operation, deviations from the normative values of material properties occur due to the uncertain nature and magnitude of the loads, which necessitates periodic shutdowns of the equipment for the purpose of diagnostics. Uninterrupted operation of elements of power equipment of marine vessels depends on the quality of control of their technical condition by physical diagnostic methods. The most effective method of reducing operating costs and increasing the reliability of equipment is maintenance based on interactive monitoring of its condition, detection of malfunctions and forecasting of energy equipment parameters. This makes the tasks of control, diagnosis and forecasting of energy equipment parameters particularly relevant. At the same time, the use of various diagnostic methods does not allow taking into account all the features of real operating conditions. This problem is especially acute in conditions of various extreme situations and peak loads, which cannot be taken into account. Probabilistic methods, in particular Markov chains, are a promising area of research. The system of intelligent diagnostics and monitoring of ship power plant turbochargers using Markov chains is presented. The novelty of the developed methodology lies in replacing discrete time intervals of the diagnostic process with a sequence of states of technical objects. In this formulation, Markov chains represent a synthetic property that accumulates diverse factors. Randomization of stochastic diagnostic and monitoring processes of ship power plant components enables an increase in reliability of equipment under severe operating conditions. The results of calculations of digitalization of experimental data, calculations of transition matrices and construction of an orgraph allowing to study the kinetics of damage accumulation in real time are presented.

ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ ФУНКЦИОНАЛЬНЫХ ХАРАКТЕРИСТИК ТЯГОВЫХ АККУМУЛЯТОРОВ ГЕЛЕВОГО ТИПА

The results of an experimental assessment of the functional characteristics of gel-type traction batteries (AGBT) for small-sized transport and technological vehicles (TVT), depending on various load modes and temperature conditions, are presented. Experimental assessment of the battery life of AGBT in operation and their discharge type characteristics at various storage and operating temperatures. An assessment of changes in the voltage level of an AgBT sample of type RuTrike 6-EVF-32 at room temperature and in a freezer (from -7.8 to -20.2 °C) with a connected electrical load and in storage mode was carried out at the first stage. Temperature fluctuations were set randomly to simulate real operating conditions of the TTS in the cold season. At the second stage of testing, the continuous operation time of a set of five battery packs as part of a small-sized vehicle, the D4 1800 tricycle, was assessed. The tests were carried out in the early spring on the territory of the Federal National Research Center VIM. Both batteries were discharged by only 0.05 V during four days of studying self-discharge characteristics at different temperatures. After removing the load, the batteries are regenerated to a voltage of 12 V (50% charge). A cold battery discharges faster by 2-3 hours, but when the load is removed it is regenerated faster. The tricycle can travel 22.21 km at a speed of 13.3 km/h on a single AkBg charge. The voltage drop across the batteries has an almost linear dependence on the distance traveled and the test time. Timely charging of the battery, as well as the provision of design and technological measures for insulating the battery pack, is recommended for operation in the cold season. Tests with cycles of movement and stopping to assess the influence of the battery’s ability to self-recovery to increase the duration of movement needs to be continued, as well as testing for the duration of recovery after turning on/removing the load, depending on the magnitude of the residual stress.