Reactive material projectiles can be an extremely efficient lethality enhancement technology that incorporates the defeat mechanisms of chemical energy and kinetic energy.This paper presents such a research on the enh...Reactive material projectiles can be an extremely efficient lethality enhancement technology that incorporates the defeat mechanisms of chemical energy and kinetic energy.This paper presents such a research on the enhanced ignition behavior of reactive material projectiles impacting a fuel-filled tank.Firstly,the ignition process description of the fuel-filled tank impacted by inert metal and reactive material projectiles is presented.Secondly,ballistic impact experiments are performed to investigate the ignition effects of the fuel-filled tank impacted by reactive material versus tungsten alloy projectiles with mass matched.The fuel tank used for the experiments is a cylindrical steel casing structure filled with aviation kerosene and sealed with aluminum cover plates on both ends using screw bolts.The experimental results indicate that,compared with impacts from tungsten alloy projectiles,there is dramatically enhanced structural damage to the fuel-filled tank and an enhanced ignition effect caused by reactive material projectile impacts.Finally,an analytical model is developed,by which the effects of the aluminum cover plate thickness on critical structural failure energy of the fuel-filled tank and the total energy of the reactive material projectile deposited into the fuel-filled tank are discussed.The analysis shows a good agreement with the experiments.展开更多
Macro-instability(MI)is an important natural phenomenon affecting the mixing performance in stirred tank significantly,which results from movement and evolution of large eddies.Factors associated with MI frequency in ...Macro-instability(MI)is an important natural phenomenon affecting the mixing performance in stirred tank significantly,which results from movement and evolution of large eddies.Factors associated with MI frequency in mixing operation and energy dissipation related to MI were reviewed.Flow pattern in turbulent regime contains many coherent structures,which have much energy vortices and may result in flow field MI.Adjustment of coherent structure and controlling MI may contribute to energy saving and good mixing performance.Controlling methods for MI was prospected.展开更多
This paper presented a preliminary research on the central solar heating system with seasonal storage(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in t...This paper presented a preliminary research on the central solar heating system with seasonal storage(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was followed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which decreases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition,the relationship between the solar collector efficiency and storage water temperature is also obtained,it decreases quickly with increasing storing water temperature,and then increases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.展开更多
Enhanced damage to the full-filled fuel tank,impacted by the cold pressed and sintered PTFE/Al/W reactive material projectile(RMP)with a density of 7.8 g/cm3,is investigated experimentally and theoretically.The fuel t...Enhanced damage to the full-filled fuel tank,impacted by the cold pressed and sintered PTFE/Al/W reactive material projectile(RMP)with a density of 7.8 g/cm3,is investigated experimentally and theoretically.The fuel tank is a rectangular structure,welded by six pieces of 2024 aluminum plate with a thickness of 6 mm,and filled with RP-3 aviation kerosene.Experimental results show that the kerosene is ignited by the RMP impact at a velocity above 1062 m/s,and a novel interior ignition phenomenon which is closely related to the rupture effect of the fuel tank is observed.However,the traditional steel projectile with the same mass and dimension requires a velocity up to 1649 m/s to ignite the kerosene.Based on the experimental results,the radial pressure field is considered to be the main reason for the shear failure of weld.For mechanism considerations,the chemical energy released by the RMP enhances the hydrodynamic ram(HRAM)effect and provides additional ignition sources inside the fuel tank,thereby enhancing both rupture and ignition effects.Moreover,to further understand the enhanced ignition effect of RMP,the reactive debris temperature inside the kerosene is analyzed theoretically.The initiated reactive debris with high temperature provides effective interior ignition sources to ignite the kerosene,resulting in the enhanced ignition of the kerosene.展开更多
This paper puts forward an unprecedented avoidance-striking-arrival problem aiming to address the need for tank's uncertain mechanical systems on the intelligent battlefield.The associated system uncertainties(pos...This paper puts forward an unprecedented avoidance-striking-arrival problem aiming to address the need for tank's uncertain mechanical systems on the intelligent battlefield.The associated system uncertainties(possibly rapid)are time-varying but bounded(possibly unknown).The goal is to design a controller that enables the tank to aim at and attack the enemy tank while keeping itself(out of the enemy fire zone).The tank maintains this condition until reaching the predefined region.In this paper,an approximate constraint following control method is adopted to solve this problem,and the original constraints are creatively divided into two categories:the avoidance-tracking constraint and the striking-arrival constraint.An adaptive robust control method is proposed and consequently verified through simulation experiments.It is proved that the system fully obeys the avoidance-tracking-constraint and strictly obeys the striking-arrival constraint under the control input.Besides,the control of the tank vehicle running system and tank gun bidirectional stabilization system are unified to deal with the control signal delay caused by complex uncertainties on the battlefield.Overall,this paper reduced the delay of signal transmission in the system while solved the avoidance-striking-arrival problem.展开更多
This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oi...This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.展开更多
In the industrial process of producing the strong phosphoric acid(SPA),clarification of the solution is essential to the ultimate product.However,the large viscosity of sediment and the induced interface interaction r...In the industrial process of producing the strong phosphoric acid(SPA),clarification of the solution is essential to the ultimate product.However,the large viscosity of sediment and the induced interface interaction result in difficulties when the SPA is clarified.CFD numerical methodology was applied to simulate internal flow field and performance of the low speed scraper based on Mixture solidliquid two-phase flow model.Sediment deposition was generated by loading solid particles at the bottom of clarifying vessel.The moving mesh and RNG k-εmodel were used to simulate the rotational turbulent flow in clarifying tank.Variables studied,amongst others,were the scraper rotation speed and the mounting height,which could affect the solid suspension height.Features of flow field and solid volume fraction distribution in computational domain were presented and analyzed.The numerical reports of the scraper torque and velocities of inlet and outlet filed were obtained.It seems the torque value of rotatio-nal axis and particle suspending height augment with an increasing rotating speed.Meanwhile,a high revolving speed is good for the deposition discharge.The particle fraction distribution in meridional surface and horizontal surface at fixed rotation speed were analyzed to determine the corresponding optimal installation height.The simulating results reflect the flow field is marginally stirred by the scraper and proper working parameters are obtained,in which case the comprehensive properties of the scraper and the clarifying tank are superior.展开更多
A moving target tracking control problem for marching tank based on adaptive robust feedback control scheme is addressed.A series of preparations is needed for tank gun before shooting a target,the purpose of this pap...A moving target tracking control problem for marching tank based on adaptive robust feedback control scheme is addressed.A series of preparations is needed for tank gun before shooting a target,the purpose of this paper is to design a control system to fulfill two requirements in this process:the turretbarrel system of tank needs to be adjusted from off-target position to command position and point to the moving target stably when there are strong uncertainties(modeling error,uncertain disturbance with unknown boundaries and road excitation) in the system.Considering the characteristic of coupled interaction,the first thing we do in this paper is to build a coupled analysis model of turret-barrel system with uncertainty term in state-space form.Second,an adaptive robust feedback control scheme is proposed by adding adaptive law to overcome the uncertainty.Third,multi-body dynamics software is used to establish the mechanical mechanism of the tank,and DC-motor module is established in SIMULINK environment,thus the target information and tracking error of the control system is collected and transferred,the gear-ball screw is derived directly by the output torque of the DC-motor module.Finally,the control system and the 3D model are combined together by means of Recur Dyn/SIMULINK co-simulation,the turret-barrel system of tank can approximately track the moving target in a certain range.With the adaptive robust feedback control,the target action is completely followed when the target location is constantly changing.展开更多
基金funded under the National Innovation and Exploration Research Programsupported by the State Key Laboratory of Explosion Science and Technology Foundation of China
文摘Reactive material projectiles can be an extremely efficient lethality enhancement technology that incorporates the defeat mechanisms of chemical energy and kinetic energy.This paper presents such a research on the enhanced ignition behavior of reactive material projectiles impacting a fuel-filled tank.Firstly,the ignition process description of the fuel-filled tank impacted by inert metal and reactive material projectiles is presented.Secondly,ballistic impact experiments are performed to investigate the ignition effects of the fuel-filled tank impacted by reactive material versus tungsten alloy projectiles with mass matched.The fuel tank used for the experiments is a cylindrical steel casing structure filled with aviation kerosene and sealed with aluminum cover plates on both ends using screw bolts.The experimental results indicate that,compared with impacts from tungsten alloy projectiles,there is dramatically enhanced structural damage to the fuel-filled tank and an enhanced ignition effect caused by reactive material projectile impacts.Finally,an analytical model is developed,by which the effects of the aluminum cover plate thickness on critical structural failure energy of the fuel-filled tank and the total energy of the reactive material projectile deposited into the fuel-filled tank are discussed.The analysis shows a good agreement with the experiments.
基金financially supported by Natural Science Foundation of China(20806095)ScientificResearch Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(教外司留20091341-2)+1 种基金China Postdoctoral Science Foundation(20080430747)National High Technology Researchand Development Program of China(2008AA031202)
文摘Macro-instability(MI)is an important natural phenomenon affecting the mixing performance in stirred tank significantly,which results from movement and evolution of large eddies.Factors associated with MI frequency in mixing operation and energy dissipation related to MI were reviewed.Flow pattern in turbulent regime contains many coherent structures,which have much energy vortices and may result in flow field MI.Adjustment of coherent structure and controlling MI may contribute to energy saving and good mixing performance.Controlling methods for MI was prospected.
基金Supported by Multi-Discipline Scientific Rearch Foundation of Harbin Institute of Technology(HIT MD2003.1)Postdoctoral Scientific Rearch Foundation of Heilongjiang Provine(LBH-Q06066)
文摘This paper presented a preliminary research on the central solar heating system with seasonal storage(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was followed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which decreases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition,the relationship between the solar collector efficiency and storage water temperature is also obtained,it decreases quickly with increasing storing water temperature,and then increases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.
文摘Enhanced damage to the full-filled fuel tank,impacted by the cold pressed and sintered PTFE/Al/W reactive material projectile(RMP)with a density of 7.8 g/cm3,is investigated experimentally and theoretically.The fuel tank is a rectangular structure,welded by six pieces of 2024 aluminum plate with a thickness of 6 mm,and filled with RP-3 aviation kerosene.Experimental results show that the kerosene is ignited by the RMP impact at a velocity above 1062 m/s,and a novel interior ignition phenomenon which is closely related to the rupture effect of the fuel tank is observed.However,the traditional steel projectile with the same mass and dimension requires a velocity up to 1649 m/s to ignite the kerosene.Based on the experimental results,the radial pressure field is considered to be the main reason for the shear failure of weld.For mechanism considerations,the chemical energy released by the RMP enhances the hydrodynamic ram(HRAM)effect and provides additional ignition sources inside the fuel tank,thereby enhancing both rupture and ignition effects.Moreover,to further understand the enhanced ignition effect of RMP,the reactive debris temperature inside the kerosene is analyzed theoretically.The initiated reactive debris with high temperature provides effective interior ignition sources to ignite the kerosene,resulting in the enhanced ignition of the kerosene.
基金This work was partially supported by the Provincial Natural Science Foundation of Jiangsu(Project no.BK20180474)the Natural Science Foundation of China(Project no.51805263,no.51705253,no.11572158).
文摘This paper puts forward an unprecedented avoidance-striking-arrival problem aiming to address the need for tank's uncertain mechanical systems on the intelligent battlefield.The associated system uncertainties(possibly rapid)are time-varying but bounded(possibly unknown).The goal is to design a controller that enables the tank to aim at and attack the enemy tank while keeping itself(out of the enemy fire zone).The tank maintains this condition until reaching the predefined region.In this paper,an approximate constraint following control method is adopted to solve this problem,and the original constraints are creatively divided into two categories:the avoidance-tracking constraint and the striking-arrival constraint.An adaptive robust control method is proposed and consequently verified through simulation experiments.It is proved that the system fully obeys the avoidance-tracking-constraint and strictly obeys the striking-arrival constraint under the control input.Besides,the control of the tank vehicle running system and tank gun bidirectional stabilization system are unified to deal with the control signal delay caused by complex uncertainties on the battlefield.Overall,this paper reduced the delay of signal transmission in the system while solved the avoidance-striking-arrival problem.
文摘This paper creates 3D solid model and assembly of U RJ 92-6 oil tank and analyses its strength by integrated CAD/CAE/CAM software I-D EAS. Through integrated simulation in computer, design efficiency and quality of oil tank is greatly improved. Adopting integrated CAD/CAE/CAM software to carry out integrated research to equ ipment and products, we will be able to take overall analysis in aspects of 3-D solid modeling, pre-assembly and strength, etc., to realize non-paper designi ng and parallel designing. Problems can be found and settled during designing, w hich will increase designing efficiency and one-time success rate and realize o ptimum designing for products.
基金Graduate Research and Innovation Program in Jiangsu Province(KYZZ16_0286)
文摘In the industrial process of producing the strong phosphoric acid(SPA),clarification of the solution is essential to the ultimate product.However,the large viscosity of sediment and the induced interface interaction result in difficulties when the SPA is clarified.CFD numerical methodology was applied to simulate internal flow field and performance of the low speed scraper based on Mixture solidliquid two-phase flow model.Sediment deposition was generated by loading solid particles at the bottom of clarifying vessel.The moving mesh and RNG k-εmodel were used to simulate the rotational turbulent flow in clarifying tank.Variables studied,amongst others,were the scraper rotation speed and the mounting height,which could affect the solid suspension height.Features of flow field and solid volume fraction distribution in computational domain were presented and analyzed.The numerical reports of the scraper torque and velocities of inlet and outlet filed were obtained.It seems the torque value of rotatio-nal axis and particle suspending height augment with an increasing rotating speed.Meanwhile,a high revolving speed is good for the deposition discharge.The particle fraction distribution in meridional surface and horizontal surface at fixed rotation speed were analyzed to determine the corresponding optimal installation height.The simulating results reflect the flow field is marginally stirred by the scraper and proper working parameters are obtained,in which case the comprehensive properties of the scraper and the clarifying tank are superior.
基金supported by the Natural Science Foundation of Jiangsu Province(Project no.BK20180474)the Natural Science Foundation of China(Project no.51805263,no.51705253,no.11572158)the National Defense Basic Scientific Research program of China(Grant no.JCKY2017208A001)。
文摘A moving target tracking control problem for marching tank based on adaptive robust feedback control scheme is addressed.A series of preparations is needed for tank gun before shooting a target,the purpose of this paper is to design a control system to fulfill two requirements in this process:the turretbarrel system of tank needs to be adjusted from off-target position to command position and point to the moving target stably when there are strong uncertainties(modeling error,uncertain disturbance with unknown boundaries and road excitation) in the system.Considering the characteristic of coupled interaction,the first thing we do in this paper is to build a coupled analysis model of turret-barrel system with uncertainty term in state-space form.Second,an adaptive robust feedback control scheme is proposed by adding adaptive law to overcome the uncertainty.Third,multi-body dynamics software is used to establish the mechanical mechanism of the tank,and DC-motor module is established in SIMULINK environment,thus the target information and tracking error of the control system is collected and transferred,the gear-ball screw is derived directly by the output torque of the DC-motor module.Finally,the control system and the 3D model are combined together by means of Recur Dyn/SIMULINK co-simulation,the turret-barrel system of tank can approximately track the moving target in a certain range.With the adaptive robust feedback control,the target action is completely followed when the target location is constantly changing.
