bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive scheduling algorithm for phased array fire control radar based on comprehensive priority
Authors: Wang Yansong , Han Xing , Chen Chun 
Published: June 2023

Abstract
Aiming at the problem of resource allocation in multi-task scheduling of phased array fire control radar, this paper proposes an adaptive scheduling algorithm based on comprehensive priority, that is, the shooting advantage degree of phased array fire control radar to different targets is calculated by using Analytic Hierarchy Process, and then combined with the priority of the work mode and the task deadline to carry out the comprehensive priority planning of the task. In the performance evaluation algorithm, the index of shooting value rate is proposed to evaluate the performance of the scheduling algorithm for high shooting advantage degree tasks. The simulation results show that, compared with the traditional scheduling algorithm, the proposed scheduling algorithm significantly improves the shooting value rate and the comprehensive scheduling ability of phased array fire control radar.
Investigation of Gas Exchange Process on a Highly-Intensified Single Cylinder Diesel Engine with Late Intake Valve Closing Miller Cycle
Authors: Wang Ziyu , Cheng Xiuwei , Liu Jinlong , Li Xiaojuan , Cao Rulou , Li Chaofan , Che Kaikai , Li Yufeng 
Published: June 2023

Abstract
Late intake valve closing (LIVC) Miller cycle was used on a highly-intensified single cylinder diesel engine to reduce the maximum combustion pressure and temperature. Three intake cams with three LIVC timings were designed and tested on the engine bench. The gas exchange process of the Miller cycle was investigated by a 1-D simulation model which was calibrated by experimental data. The analysis was conducted at a constant speed of 3600 r/min and two IMEP loads of 25 bar and 15 bar respectively. Miller depth is named to reflect the retard degree of the LIVC timing. The analysis results show that as the LIVC Miller depth increases, the intake pressure is considerably increased in order to keep the same load. This causes an increase in intake boost work. In addition, the averaged intake pressure difference during the period of BDC-IVC is negative and increases with the retard of IVC timing, resulting in more backflow with the LIVC timing. The backflow rate quickly increases from nearly zero at the original IVC timing of 70°CA ABDC to 22% at the deepest LIVC timing of 120°CA ABDC. Furthermore, the charging efficiency and pumping loss reduce with the retard of IVC timing. The Miller loss is obviously increased at deeper LIVC Miller cycle. On the other hand, the exhaust energy slightly decreases with the retard of IVC timing in this study case, but the ratio of the boost work over the exhaust energy increase considerably with the retard of IVC timing.
Influence of slenderness ratio on the lateral force of a slender body at high angle of attack
Authors: Wei K , Chen S S 
Published: June 2023

Abstract
The slenderness ratio is an important feature of the slender body, but the effect of slenderness ratio on the lateral force of the slender body at high Angle of attack have not clearly. In this paper, the Detached eddy simulation (DES) method is verified and adopted to simulate the flow of five models with slenderness ratio SR=10, 12.5, 15, 17.5 and 20. The simulation is carried out under the conditions of 15.3m/s incoming flow and 55° Angle of attack. Based on the simulation results, the vorticity magnitude and surface pressure coefficient of the five models are compared. It is concluded that the increase of slenderness ratio will increase the fluctuation cycle of pressure along the axial direction. To further analysed the relationship between pressure distribution and lateral force in different models, the pressure values of multiple sections were extracted and integrated to draw the change curve of unit lateral force coefficient along the X direction. From the analysis of unit lateral force coefficient, the difference of pressure between the two sides induced by asymmetric vortex at the head is the main source of lateral force. The unit lateral force coefficient (Cfzpm
) of the model with small slenderness ratio oscillated more dramatically and attenuated more slowly than that of the model with large slenderness ratio, due to the interaction between the head vortex and the high-pressure region at the bottom of body with a small slenderness ratio at a large Angle of attack. The interaction between the head vortex and the bottom high-pressure region makes the lateral force coefficient of the model with small slenderness ratio not necessarily significantly smaller than that of the model with large slenderness ratio. With the increase of slenderness ratio, the influence of head vortex on the pressure distribution of rear surface decreases, and the asymmetry of rear surface pressure distribution decreases. The conclusion of this paper can help to solve the problem of lateral force coefficient variation that may occur in multistage rocket engineering.
Propagation characteristics of rotating detonation with high-temperature hydrogen gas
Authors: Bai Q D , Han J X , Zhang S J 
Published: June 2023

Abstract
The rotating detonation characteristics of high-temperature hydrogen-rich gas were studied. Hydrogen-rich gas was generated by the pre-combustion of hydrogen, and a rotating detonation experiment of hydrogen-rich gas and air was subsequently performed. The auto-initiation of high-temperature hydrogen-rich gas was observed in the experiment, and the influence of pre-detonation tube ignition on the steady propagation of the detonation wave was analyzed. The results show that high-temperature hydrogen-rich gas and air have the ability to spontaneously form rotating detonation waves. The operation of the pre-detonation tube has a significant influence on the propagation mode and propagation velocity of the continuous rotating detonation wave after auto-initiation. The rotational detonation wave formed by the auto-initiation of hydrogen-rich gas and air has a short instability in the propagation process. The propagation velocity of the detonation wave before and after the unstable state is 1345.4 m/s and 1425.3 m/s, respectively, the unstable state is 1345.4 m/s and 1425.3 m/s, respectively.
Research on Synchronous Accuracy of Sight and Gun in Remote Control Weapon Station
Authors: Jie Li , Haibo Wang , Xiaobin Pang , Xingwang Liang 
Published: June 2023

Abstract
The synchronous accuracy of sight and gun is an important factor affecting shooting accuracy and first hit probability of remote control weapon station. In view of the problem that the angle between the line of sight (LOS) and the line of gun (LOG) in high and low direction is not consistent, this paper analyzes the cause of the angle between the LOS and the LOG in high and low direction in a batch of remote control weapon station production, and according to each kind of influence factor has given the corresponding solution measure. It is proved that the synchronous accuracy of sight and gun in remote control weapon station can be improved effectively through precision control of each link.
Research on automatic metering and pneumatic vibration conveying technology of energetic powder materials
Authors: He Fei , Yang Hao , Sun Yang , Liu Jinsong , Gu Peng , Jia Yunpeng , Mu Jiaqing , Li Jing , Ou Xibin , Zhu He 
Published: June 2023

Abstract
In view of the need to improve the automation and weighing accuracy of solid energetic materials in the weighing process, to reduce the process safety risk of the automatic conveying and loading process and improve the equipment safety control ability, a weight-loss pneumatic vibration conveying device is designed, which adopts the method of weight loss measurement. Through the weighing sensor installed on the weighing platform, the weight of the materials in the weighing hopper is fed back to the controller in real time, The controller obtains the weight reduction per unit time (i.e. the actual flow) through the internal algorithm. According to the difference between the actual flow and the set flow, the controller outputs the speed signal to control the motor speed to achieve the purpose of accurate feeding. A linear pneumatic vibrating conveying chute is designed to continuously convey materials at a certain speed. The linear pneumatic vibrating chute has good linear control through the adjustment of leaf spring, amplitude and frequency, and can realize the automatic and safe measurement and transportation of solid energetic materials.
Sensitivity Study on Typical Parameters of Underwater Explosion Numerical Simulation
Authors: Chen D , Zhang L J , Lv Y Z , Li B H , Gu H P 
Published: June 2023

Abstract
In the numerical simulation research for underwater explosion, the selection of simulation parameters has a great influence on the results of numerical calculation. Based on the one-dimensional spherical symmetry model, this paper systematically studies the influence of three factors: grid size, water state equation and artificial viscosity coefficient on the important physical parameters of water explosion when TNT explosive is exploded in water. The important physical parameters selected for the explosion in water are the shock wave intensity, the maximu m radius of the bubble and the pulsation period of the bubble. A series of studies are carried out on underwater explosions with different grid sizes, so as to obtain the corresponding recommended grids that meet the calculation accuracy. The influence of different water state equations on the simulation results is discussed. The effect of artificial viscosity coefficient on the simulation results is analyzed. Finally, the similarity law of the model is studied to verify the universality of the model parameters.
A modified formula to predict the penetration depth for jet penetrating spaced target plates
Authors: Lei J Y , Dou J H , Jing Y D 
Published: June 2023

Abstract
In order to predict the penetration depth for jet penetrating spaced target plates, a modified formula with exponential form is proposed in this work based on the existing method. The processes of jet penetrating homogeneous target plate and spaced target plates are observed by simulation, and the penetration depth of different layers is obtained. The relationship between the number of layers and the penetration depth is described by the proposed formula, in which the parameters are determined by the simulation results. The penetration depth for jet penetrating spaced target plates can be predicted by the proposed formula. By comparison, the predictions well agree with the actual data, which indicates the modified formula can be a reference to predict the penetration depth for spaced target plates.
Study on Thermal Decomposition and Thermal Safety of Mixtures of Highly Active Aluminum Powder and Nitramine Explosive
Authors: Pei Qing , Li Meng , Li Heng 
Published: June 2023

Abstract
The newly prepared and stored highly active aluminum powder were mixed with common nitramine explosives HMX and CL-20 at a mass ratio of 1:1, respectively. The effects of the two kinds of high active aluminum powder on the thermal decomposition properties of HMX and CL-20 were investigated by differential scanning calorimetry (DSC). The thermal explosion critical temperature of the mixture of high active aluminum powder and nitramine explosive was calculated. The result shows that after joining highly active aluminium powder, highly active aluminium/nitramine explosive mixture, moderate and apparent activation energy decrease thermal decomposition peak suggests that highly active aluminium can contribute to the thermal decomposition of HMX and CL-20, compared with highly active aluminium stored after a certain period of time, the new system is highly active aluminum powder with a mixture of nitramine explosives with lower apparent activation energy, At the same time, the critical temperature of thermal explosion also decreased significantly, which indicated that the newly prepared high-activity aluminum powder had higher chemical reactivity, but its thermal safety was reduced.
Numerical simulation study on the slow cook-off response characteristics of PBX explosive
Authors: hai Deng , xin-lian Ren , sha Gou 
Published: June 2023

Abstract
The zero order reaction kinetic model was used to simulate the heating of energetic binder PBX charge at four heating rates of 3.3K/h, 6K/h, 9K/h and 30K/h, respectively. The key parameters such as the evolution of temperature field, ignition time, ignition temperature and ignition area were obtained. The results show that during the slow Cook-off process of energetic binder PBX explosive charge, before the thermal decomposition and acceleration reaction, it is a heat conduction process, with large internal temperature gradient, low charge center temperature and high charge edge temperature; When the temperature rises to 396K, the thermal decomposition rate of the explosive increases, and heat accumulation occurs in the charge; The ignition position of charges with different heating rates changes. With the increase of heating rates, the ignition position changes from a point in the center to two points on the axis that gradually move away from the center to both ends, and then to four points that gradually move away from the axis to four end angles. Finally, the ignition reaction occurs.
Intracranial pressure measurement under shock wave based on physical head surrogate
Authors: Xiong Man-Man , Tian Cong-ling , An Shuo , Zang Li-wang , Xu Cheng , Li Feng-xia 
Published: June 2023

Abstract
In order to explore the intracranial pressure response under different sensor fixation modes, the experimental study on the pressure measurement based on physical head surrogate under shock wave is carried out. The influence of different sensor fixation methods on the intracranial pressure was analyzed. The results show that sensor fixation mode has little influence on the pressure test results. The deviation between the pressure peak and impulse is only 3.62% and 4.54% in the two modes of hot melt supporting and free suspension. The deviation of pressure peak value between metal supporting and free suspension is 5.59%. In comparison, hot melt supporting fixation has less influence on intracranial pressure results. The orientation of sensor sensitive surface has little influence on the pressure test results. When sensor was fixed by the metal bracket, the deviation of pressure peak is only 4.03% between sensitive surface face to impact source and sensitive surface back to shock source.
Quasi-static and dynamic mechanical characterization of clay and ballistic soap
Authors: Wang L Q , Wen Y K , Dong F D , Qin B , Qu Y , Sun F 
Published: June 2023

Abstract
Ballistic gelatin, soap, and clay are three human simulated target materials commonly used in the field of wound ballistics research. Currently, there are more studies on ballistic gelatin’s mechanical properties, but rarely on clay and soap. In this paper, the mechanical properties of clay and soap materials were tested by using universal material testing machine and Hopkinson bar, respectively, and their stress-strain curves were obtained under different temperatures (4°C, 15°C, and 25°C) from quasi-static to dynamic loading. The test results showed that the clay material was sensitive to temperature and strain rate in quasi-static conditions, its stress-strain curves showed nonlinear strengthening characteristics, and the stress always increased without strength decrease during the loading process; the dynamic compression mechanical properties of clay were significantly higher than the quasi-static mechanical properties, showing obvious strain rate strengthening effect. In quasi-static compression experiments, the stress-strain curves of soap material showed bilinear elastic-plastic material characteristics; when the strain was less than 0.1, it was insensitive to temperature and strain rate, and only when the strain was more significant than 0.1 did it show a certain temperature and strain rate correlation. The dynamic compressive mechanical properties of soap are significantly higher than the quasi-static mechanical properties, showing a significant strain-rate strengthening effect. The stress of soap at the same strain rate is slightly less than that of clay. These results not only help provide more accurate material parameters for relevant numerical calculations but also help to provide references for the development of new bionic materials.
Effect of ventilation mode and rate on airborne transmission of respiratory disease in indoor environments
Authors: Wu Jialin , Geng Jing , Weng Wenguo , Fu Ming 
Published: June 2023

Abstract
Ventilation might play an important role in airborne transmission. By using the computational fluid dynamics (CFD) method, ventilation modes, ventilation rates, and infection source’s face direction were considered in a multi-person indoor environment (10 m*10 m*3 m). The airflow patterns, virus concentration distribution, and infection probability were studied. The results showed that the virus concentration was lower with displacement ventilation (DV, lower in, upper out) than mixing ventilation (MV, top-centre in, upper out) or natural ventilation (NV, upper in, upper out). In 2 air changes per hour (ACH), the infection risk of susceptible persons in MV and NV might be about 2.43-fold and 1.30-fold more than that in DV. Increased ventilation usually reduces viral concentrations and the risk of infection. For the height of breathing zones, the average virus concentration at 12ACH was 49.78%-78.72% lower than that at 2ACH. For susceptible persons at a distance of about 2.8-4.2 m to a COVID-19 infector with 30 min exposure time, the long-range airborne infection probability might be 11.53% (±5.86) (2ACH), 4.96% (±1.82%) (6ACH), and 2.96% (±1.91%) (12ACH).
Effect of solution and aging treatment on microstructure and hardness of aluminum bronze
Authors: Chen Shan , Zhang Peng , Jia Dongsheng , He Yaoyu , Zhang Liqin , Zhou Jiawei , Xue Dong , Yue Feng 
Published: June 2023

Abstract
Due to their excellent corrosion resistance and wear resistance, bearing bushes made of aluminium bronze are widely used in pumps, heavy equipment and marine equipment. Aluminium bronze is also used in valve for tank to improve defence. This work aims to enhance the hardness of QAl10-3-1.5 extruded aluminium bronze by performing heat treatment at different solution temperature, quenchant, and aging temperature. The results show that when the aluminum content of the raw material is more than 9.4%, aluminum bronze after solution and aging treatment obtain a significant enhancement of hardness. The value of hardness can reach above 207HB, which meets the design requirements of drawings and improves the wear and corrosion resistance.
Simulation Study of Structural Factors Affecting the Performance of Thermal Jacket for Gun Tubes
Authors: Duan Dongyu , Zhang Jie , Li Ying , Sun Quanzhao 
Published: June 2023

Abstract
Most of common thermal jackets for gun tubes are composite types, which have large mass and complex structures. With the development of material technology, a single-layer thermal jacket using new composite materials with low thermal conductivity has good protection effects on gun tubes. The design of a single-layer thermal jacket requires consideration of thickness, air gap, material properties and structural strength. In order to study the structural factors that affect the performance of the single-layer heat jacket, the models of various structural dimensions through a 3D modeling software were established, a thermal-mechanical coupling system was built using a finite element simulation software to simulate the different thermal jacket models. The results were compared and analyzed, and the structural factors that affect the performance of the thermal jacket were investigated.
Experiment and instantaneous driving simulation of explosion dispersion process of central tube for submunition
Authors: Peng Hong Zheng , Yuan Jun Ming , Huang Si Fan , Huang Kai Shu , Zhao Wei , Liu Jia Yao , Qin Yue , Zhou Han Peng 
Published: June 2023

Abstract
In order to study the influence of explosion dispersion of submunition on the dispersion velocity and pressure characteristics of subunits, the experimental study of explosive dispersion of the central tube was carried out when the explosives with low detonation velocity were applied in central tube as the main charge. In addition, the explosion dispersion test process was recorded by high-speed photography. RDX-based aluminized explosive samples with low detonation velocity were prepared and tested, and the low detonation velocity performance changes under different charge diameters and densities were obtained. Based on the explosive dispersion test of the central tube of the submunition, the physical model and three-dimensional axisymmetric finite element model of the central tube, subunit and aluminium alloy shell with prefabricated grooves are established. The fluid-structure coupling calculation method is used to simulate the explosive dispersion process. The simulation results are compared with the test results, and the pressure distribution characteristics of the subunit and the variation law of the dispersion velocity are analyzed. The effectiveness of the engineering calculation method of JWL equation model parameters is verified. The results show that using RDX based aluminized low detonation velocity explosive as the main charge of the central tube structure can achieve the design goal of the explosive dispersion for submunition, and the explosion dispersion model of submunition can accurately describe the dispersion characteristics of the subunit. The research results can be used to guide the structural design of submunition warhead.
Optimization of Al/PTFE applied to detonation network used for micro shaped charge warhead.
Authors: Wen X M , Wang S , Kang H , Wang J H 
Published: June 2023

Abstract
In order to improve the detonation performance of the explosive network on the basis of achieving high safety and reliable detonation, 3,4-dinitrofurazanyl oxyfurazan (DNTF) was used as the main explosive, glycidyl azide polymer(GAP) was used as the binder, and other auxiliary agents were added to the basic charge formula. Then, polytetrafluoroethylene (PTFE) and aluminum (Al) were introduced to further enhance the output power of the charge formula. The influence of two introduction methods of PTFE and Al was evaluated: directly mechanically mixing method and activation method by metal ball milling. A variety of tests such as particle size, morphology, detonation performance in groove were carried out to study the difference between mixed Al/PTFE and milling activated Al/PTFE. The experiment showed that particle size becomes smaller and Al/PTFE were well compounded. Moreover, results showed that the charge formula with milling activated Al/PTFE possessed good propagation reliability in micro linear groove and stronger external expansion capability. These properties were vital for the charge formula to be applied to the complex explosive circuits used for micro shaped charge warhead.