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The capacitated green vehicle routing problem is considered in this paper as a new variant of the vehicle routing problem. In this problem, alternative fuel-powered vehicles (AFVs) are used for distributing products. AFVs are assumed to have low fuel tank capacity. Therefore, during their distribution process, AFVs are required to visit alternative fuel stations (AFSs) for refueling. The design of the vehicle routes for AFVs becomes difficult due to the limited loading capacity, the low fuel tank capacity and the scarce availability of AFSs. Two solution methods, the two-phase heuristic algorithm and the meta-heuristic based on ant colony system, are proposed to solve the problem. The numerical experiment is performed on the randomly generated problem instances to evaluate the performance of the proposed algorithms.

The Fine  −  Kinney is a risk assessment method widely used in many industries due to its ease of use and quantitative risk evaluation. As in other methods, it is a method that recommends taking a series of control measures for operational safety. However, it is not always possible to implement control measures based on the determined priorities of the risks. It is considered that determining the priorities of these measures depends on many criteria such as applicability, functionality, performance, and integrity. Therefore, this study has studied the prioritization of control measures in Fine − Kinney-based risk assessment. The criteria affecting the prioritization of control measures are hierarchically structured, and the importance weights of the criteria are determined by the Bayesian Best–Worst Method (BBWM). The priorities of control measures were determined with the fuzzy VlseKriterijumska Optimizacija I Kompromisno Resenje (FVIKOR) method. The proposed model has been applied to the risk assessment process in a petrol station’s liquid fuel tank area. According to the results obtained with BBWM, the most important criterion affecting the prioritization of control measures is the applicability criterion. It has an importance weight of about 42%. It is followed by performance with 31%, functionality with 18%, and integrity with 10%, respectively. FVIKOR results show that the “Periodic control of the ventilation device” measure is the top priority for Fine − Kinney risk assessment. “The absence of any ducts or sewer pits that may cause gas accumulation in the tank area and near the dispenser; Yellow line marking of entry and exit and vehicle roads; Placing of speed limit warning signs” has been determined as a secondary priority. On conclusion, this proposed model is expected to bring a new perspective to the work of occupational health and safety analysts, since the priority suggested by Fine − Kinney risk analysis methods is not always in the same order as the one in the stage of taking action, and the source, budget, and cost/benefit ratio of the measure affect this situation in practice.

The ability to suppress fuel tank ignition and explosion is related to passenger safety and aircraft survivability. To enhance aircraft fuel tank safety, the on-board fuel tank inerting technology is applied to reduce the probability of fuel tank ignition and explosion, whether the fuel tank has open or closed vent system. This paper takes the single-bay fuel tank of a certain type of aircraft as the research object, establishes mathematical models of the inerting process of open and closed vent systems fuel tanks, and writes programs to carry it out based on MATLAB R2019b combined with the numerical calculation method of microelement integration according to the actual on-board hollow fiber membrane separation performance. On this basis, this paper analyzes the variation of oxygen concentration in the ullage of open and closed vent systems fuel tanks, compares their advantages and disadvantages, and explores the influence of factors on the inerting effect, such as initial oxygen concentration, fuel loading, aeration pressure, and valve diameter. The results show that for the same nitrogen-enriched air (NEA) flow rate and concentration, the inerting effect of the closed vent system fuel tank is better than the open vent system fuel tank, which can better meet the airworthiness regulations requirements on the flammability exposure time. The initial fuel loading and oxygen concentration have a more significant effect on the initial stage of inerting. Within the range of the vent valve diameters considered in this study, any appreciable difference in the oxygen concentration behavior could not be identified. When the tank pressure conditions permit, it is recommended to use a larger valve threshold to better utilize the good inerting effect of the closed vent system fuel tank.

In order to investigate the damage aftereffect of energetic materials on diesel fuel tanks, this study compares the damage effects of three energetic materials, namely CuO/Al thermite, PTFE/Al+CuO/Al composite, and Zr powder, on diesel fuel tanks. The hole area on fuel tanks and the length and duration of diesel deflagration-formed fireballs are characterized, and the damage process and mechanism of armor piercing incendiary (API) projectiles are explored. According to the results, the CuO/Al thermite releases energy rapidly during projectile penetration into the target and exhibits the highest damage power. The hole produced by the thermite projectiles has an area twice as large as that produced by the composite projectiles, and the maximum fireball induced by the thermite persists twice as long as that induced by the composite. The rapid energy release of the CuO/Al thermite is primarily attributed to the vaporization of copper atoms into free copper at high temperatures, which further increases the pressure in fuel tanks. CuO/Al-filled API projectiles at a velocity of 950 m/s can produce violent deflagration and petaling damage to diesel fuel tanks.

From the aspect of exploring the alternative lightweight composite material for the aerospace launch vehicle external fuel tank structural components, the current research work studies three different grades of Aluminium alloy reinforced with varying graphene weight percentages that are processed through powder metallurgy (P/M) route. The prepared green compacts composite ingots are subjected to microwave processing (Sintering), hot extruded, and solution treated (T6). The developed Nano-graphene reinforced composite is studied further for the strength–microstructural integrity. The nature of the graphene reinforcement and its chemical existence within the composite is further studied, and it is found that hot extruded solution treated (HEST) composite exhibited low levels of carbide (Al4C3) formations, as composites processed by microwaves. Further, the samples of different grades reinforced with varying graphene percentages are subjected to mechanical characterisation tests such as the tensile test and hardness. It is found that 2 wt% graphene reinforced composites exhibited enhanced yield strength and ultimate tensile strength. Microstructural studies and fracture morphology are studied, and it is proven that composite processed via the microwave method has exhibited good ductile behaviour and promising failure mechanisms at higher load levels.

The computations of fuel tanks are bound to cover uncertainties related to geometric and material imperfections, post-welding stresses, non-uniform settlement, and shell degradation due to corrosion. The paper compares four different methods of tank corrosion descriptions: a uniform reduction of the sheet thickness of the entire shell, degradation described by an angle correlated with its partial fuel filling, corrosion patterns defined by appropriately selected trigonometric functions, and an advanced model using theoretical random fields. All corrosion patterns were numerically investigated to identify their impact on structural response. The computations were carried out for a simplified numerical model of a mounded horizontal pressure vessel. The Point Estimate Method (PEM) was used to estimate the mean value and standard deviation of the shell critical forces. The probabilistic approach allows to assess structural reliability and makes it possible to optimize the structure. It has been shown that the optimal variant of corrosion description, easy for engineering applications, is the uniform reduction of the shell thickness.

This manuscript presents the results of the study of snow covers’ influence on the interferometric measurements of the stability of industrial infrastructure in the vicinity of Norilsk city, Russia. Fuel tanks of the Norilsk thermal power plant (TPP) were selected as an object of study due to a well-known accident when about 20,000 tons of diesel fuel spilled from one of the tanks. Sentinel-1 synthetic aperture radar data acquired over the territory of Norilsk TPP were used in the DInSAR study of the possible displacements of the tanks that could be the cause of the tank’s damage. For twelve days, radar interferograms that were generated in the study covered the cold and warm seasons of 2018–2020, including the catastrophic event—the rupture of the tank with diesel fuel—in order to shed light on the possible impact of the area subsidence because of permafrost thaw under the tanks. As the tank walls and adjacent concrete base constituted the virtual dihedral corner reflector, the accumulation of snow on the surface near the tanks created a distorting effect on the results of monitoring the stability of the tank’s location. Three models of snow layer within the dihedral proposed could help explain the deviations in the signal amplitude and phase in the case of snowfalls occurring between radar observations. We propose three ways to minimize the influence of snow on interferometric measurements. One of them, the selection of the radar data acquired in proper observation conditions, made it possible to assess the stability of the mutual location of the tanks. Among the most important processing and analysis results in the paper is a conclusion about the high stability of the fuel tank’s location on the yearly time interval, including the troubleshooting tank.

When plug-in hybrid electric vehicles (PHEVs) operate under long-term electric-only driving or extended parking conditions, the conventional passive evaporative emission control system is prone to carbon canister saturation, leading to uncontrolled vapor release into the atmosphere. To address this issue, this study proposes a novel active vapor recovery system that suppresses gasoline evaporation by actively regulating the vapor pressure in the fuel tank based on gas–liquid phase equilibrium. A dynamic vapor pressure balance model under electric-only operating conditions is established to quantify vapor generation and control demand as a function of ambient temperature variation. An experimental test platform is developed to validate both the feasibility of the proposed active control strategy and the accuracy of the vapor generation model. Experimental results show that the deviation between the theoretical and measured vapor quantities remains within 5.08%, demonstrating that the proposed method can effectively achieve quasi-zero evaporative emissions in PHEV fuel systems during electric-only operation. This study provides a new technical route beyond conventional passive control approaches for evaporative emission mitigation in PHEVs.

Fuel sloshing in fuel tank can cause adverse effects. In order to reduce the safety risk, energy waste and environmental pollution, it is essential to explore the mechanism of fuel sloshing in automobile fuel tank. The influences of different excitation conditions and sloshing parameters on fuel sloshing characteristics are numerically studied by using volume-of-fluid method, including the sloshing characteristics of free surface, dynamic pressure, sloshing force and sloshing moment. The results show that the increase of excitation frequency and amplitude will lead to more violent sloshing, obvious splashing waves and large-amplitude liquid surface breaking phenomenon. In the monitoring of the side wall dynamic pressure, the pressure at the liquid level is the maximum, followed by that above the liquid level, and the minimum below the liquid level. The dynamic pressure mainly changes periodically, and the peak dynamic pressure shows oscillation and randomness. At medium and low fill levels, the sloshing force and moment increase significantly as the fuel fill level increases, but the increase of fill level will not lead to an unlimited increase of sloshing force. In addition, the sloshing force generated by lateral sloshing is significantly higher than that of longitudinal sloshing, but the sloshing moment has little difference.

Fuel vapor catalytic inerting technology is considered to be the most promising approach to inertize aircraft fuel tanks in the future. However, the complex and fluctuating inlet operating conditions have led to issues such as low reaction efficiency and a narrow operating range for the core component, the catalytic reactor. To address these challenges, a simulation model of a two-temperature porous media catalytic reactor was established using Fluent 17.0 software. This model coupled gas–solid heat transfer and chemical reaction through user-defined functions (UDF) and user-defined scalar (UDS). The model's accuracy was verified using a self-built experimental platform. The impact of three different reactor structures—cylindrical, expanded, and tapered—on reactor performance under the same reaction conditions was compared. Operation parameters, such as the preheating temperature of the reaction gas, fuel vapor concentration (FVC), and oxygen concentration (OC), were also studied. The results showed that the expanded-shaped catalytic reactor improved the conversion rate of fuel vapor, while the tapered-shaped reactor made the temperature distribution inside the reactor more uniform and suppressed hotspots. Additionally, increasing the inlet gas temperature, FVC, and OC had a promoting effect on the catalytic reaction. Due to the adoption of appropriate cooling methods to solve the problem of reactor temperature surges, this paper recommends designing the catalytic reactor into an expanding shape to improve fuel vapor conversion rate and improve inerting system performance. The findings of this study are significant for promoting the application of catalytic inerting technology in RP-3 aviation fuel.