The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheri...The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their accuracy.The spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of view.This can result in a lower real hit probability.To increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been pro-posed.This method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser seeker.Then,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release region.This method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric visibility.By more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%.展开更多
This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube...This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube duster munitions dispersion was simulated. The state of submunitions dispersion was obtained as interior ballistic conditions changed. The effect of shell stress groove on shell opening was discussed. The shell with stree groove is helpful for submunitions dispensing effectively and uniformly. The effect of liner material on submunitions dispersing was discussed. It can be found that foam liner can reduce the interior ballistic pressure, increase the pressure action time, reduce the acceleration of the submunitions and increase the sub- munitions dispersing velocity. These results provide some reference for the theory and experiment research of the central blast tube cluster munitions dispersion.展开更多
Aerodynamics of loitering munition is studied in this paper.The aerodynamic characteristics of loitering munition with non-circular body and body-airfoil-empennage combination are calculated numerically at Ma=0.4 base...Aerodynamics of loitering munition is studied in this paper.The aerodynamic characteristics of loitering munition with non-circular body and body-airfoil-empennage combination are calculated numerically at Ma=0.4 based on multi-griddings patching technology,in the range of angle of attack-4°-10°,and the analytical results were compared with those from wind tunnel experiments,they show a good consistency.Analysis of the results showed that the normal force generated by non-circular cross-section missile increases with the angle of attack.At α≥6°,normal force achieved by missile body can take up to 10% of the total lift.Together with the lifting surface,the loitering munitions can provide a better lift to drag ratio,an improved weapon range and a good longitudinal stability.展开更多
Loitering munitions are increasingly used in armed conflicts.An extensive database of loitering munitions is developed based on information available in the public domain.This database includes dimensions,weights,and ...Loitering munitions are increasingly used in armed conflicts.An extensive database of loitering munitions is developed based on information available in the public domain.This database includes dimensions,weights,and performance parameters such as flight endurance and communication range.Based upon this dataset,6 categories of loitering munitions are identified and statistical trends in the form of equations are provided for each category.The statistical trends are supported by aircraft performance theory tailored to loitering munitions applications.Altogether,the combination of the database,statistical trends and aircraft performance theory can be used to analyse the flight performance and design considerations of new loitering munitions of which only limited non-technical information is available in the public domain such as pictures and news articles.Based on the statistical trends and aircraft performance theory it is concluded that for long range applications,the preferred design solution is the conventional configuration.The cruciform configuration is beneficial in case precision flight path control is of prime importance.The tandem wing configuration combines the benefits of a canister launch and relatively high aspect ratio wings suitable for long range flight.Finally,the delta wing design provides a large internal volume and a high terminal attack airspeed.Two example case studies are included to illustrate the flight performance capabilities of two types of loitering munitions used in the current conflict in Yemen(a long range conventional design and a delta wing configuration).展开更多
Cellulose acetate nitrate(CAN) was used as an insensitive energetic binder to improve the insensitive munitions(IM) properties of gun propellants to replace the M1 propellant used in 105 mm artillery charges.CAN conta...Cellulose acetate nitrate(CAN) was used as an insensitive energetic binder to improve the insensitive munitions(IM) properties of gun propellants to replace the M1 propellant used in 105 mm artillery charges.CAN contains the energetic nitro groups found in nitrocellulose(NC),but also acetyl functionalities,which lowered the polymer's sensitivity to heat and shock,and therefore improved its IM properties relative to NC.The formulation,development and small-scale characterization testing of several CAN-based propellants were done.The formulations,using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were completed.The small scale characterization testing,such as closed bomb testing,small scale sensitivity,thermal stability,and chemical compatibility were done.The mechanical response of the propellants under high-rate uni-axial compression at,hot,cold,and ambient temperatures were also completed.Critical diameter testing,hot fragment conductive ignition(HFCI) tests were done to evaluate the propellants' responses to thermal and shock stimuli.Utilizing the propellant chemical composition,theoretical predictions of erosivity were completed.All the small scale test results were utilized to down-select the promising CAN based formulations for large scale demonstration testing such as the ballistic performance and fragment impact testing in the105 mm M67 artillery charge configurations.The test results completed in the small and large scale testing are discussed.展开更多
Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Phoiobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.)...Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Phoiobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.). This paper reports that UV-A photoenhanced the toxicity of polynuclear aromatic hydrocarbons, other types of organic compounds, and some transition metals to P. phosphoreum. Coexposure to 400 μw/cm2 for 15 min increased the toxicity of psoralen, α-terthienyl, anthracene, acridine, fluoranthene,TNT, Cu2+, As3+, Ni2, and Cd2+. Phenanthrene was photoenhanced after 30 min coexposure at 400 μw/cm2+, and Mn2+ at 800 μw/cm2 aftef 15 min. Naphthalene was not enhanced at 800 μw/cm2 for 30 min展开更多
Mutatox is a new genotoxicity bioassay which uses as the endpoint the bioluminescence produced on reversion of a dark strain of the marine bacterium Vibrio fischeri ±S9.Reversion can occur by several mechanisms, ...Mutatox is a new genotoxicity bioassay which uses as the endpoint the bioluminescence produced on reversion of a dark strain of the marine bacterium Vibrio fischeri ±S9.Reversion can occur by several mechanisms, including base substitution, frame-shift, SOS induction, and DNA intercalation. For screening, Mutatox provides many advantages over the Salmonella trphimurium (Ames) assay: it requires minimal sterility, employs a shorter incubation period, and does not require culture maintenance. Eighteen organic chemicals (phenol, polynuclear aromatic hydrocarbons, nitrotoluenes, others), Na3PO4, and 4 genotoxic metals (Cu2+, Ni2+, As3+, Cd2+) were tested. Most of the organic compounds positive in S. typhimurium assays were positive in Mutatox. None of the metals was genotoxic in V. fischeri, possibly due to poor uptake from the saline medium展开更多
Cluster munitions release dozens of smaller bomblets that rain deadly ammunition on armored tanks, vegetation and troops, effectively striking broad areas of war zone landscapes in one launch. However, only about 60% ...Cluster munitions release dozens of smaller bomblets that rain deadly ammunition on armored tanks, vegetation and troops, effectively striking broad areas of war zone landscapes in one launch. However, only about 60% of bomblets detonate immediately and those that fail to detonate fall to the ground and can lie dormant for years. The legacy of cluster munitions in Laos from the Second Indochina War is unexploded bomblets across the landscape that unexpectedly detonate years later, injuring and killing children, farmers, and other civilians long after the war is over. In Laos, the United States (US) military operation against the Ho Chi Minh Trail, a network of foot and bicycle paths, waterways, and truck routes along the Laos, Cambodia and Vietnam borders linking North and South Vietnam began in 1959. By the 1960s, as the war escalated, trail traffic was interdicted frequently by CIA and US Air Force using tactical herbicide spraying to defoliate dense vegetation and bombing to disrupt supplies and North Vietnamese troops dispersed along the 16,000-kilometer trail. Unexploded ordinance (UXO), including cluster munitions, from U.S. bombings continued in recent years to detonate, kill, maim and injure Laotians and render agricultural lands too hazardous to cultivate. The primary objectives of this study are to document: 1) the long-term consequences and impacts of the US Air Force bombing of Laos during the Second Indochina War (1959 to 1973);2) the United States removal of unexploded ordnance and cluster munitions;and 3) worldwide relief efforts to help the Laotians maimed by unexploded ordnance and cluster munitions.展开更多
Based on the analysis of the flying scheme and flying style of an extended range guided munition(ERGM), the aerodynamic characteristics design standards were put forward. According to the standards, the ERGM aerodynam...Based on the analysis of the flying scheme and flying style of an extended range guided munition(ERGM), the aerodynamic characteristics design standards were put forward. According to the standards, the ERGM aerodynamic configuration was designed, and the wind tunnel experiments were processed. The experimental results show that the configuration has lower drag and good static stability at unguided flying stage. Moreover, the stability, maneuverability, rudder deflection angle and balance angle of attack of the configuration are all reasonably matched at guided flying stage, and the munition with the configuration can glide with larger lift-drag ratio at little balance angle of attack. The experimental results also indicate that the canard can't conduct rolling control when 1.0 ＜ Ma ＜ 1.5, so the ERGM must take rolling flight style with certain limited rolling speed.展开更多
基金This work was supported by the major research projects within the military-international class(JY2021B077).
文摘The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of use.LGBs are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their accuracy.The spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of view.This can result in a lower real hit probability.To increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been pro-posed.This method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser seeker.Then,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release region.This method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric visibility.By more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%.
文摘This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube duster munitions dispersion was simulated. The state of submunitions dispersion was obtained as interior ballistic conditions changed. The effect of shell stress groove on shell opening was discussed. The shell with stree groove is helpful for submunitions dispensing effectively and uniformly. The effect of liner material on submunitions dispersing was discussed. It can be found that foam liner can reduce the interior ballistic pressure, increase the pressure action time, reduce the acceleration of the submunitions and increase the sub- munitions dispersing velocity. These results provide some reference for the theory and experiment research of the central blast tube cluster munitions dispersion.
基金Sponsored by the Ministerial Level Advanced Research Foundation(51305010102)
文摘Aerodynamics of loitering munition is studied in this paper.The aerodynamic characteristics of loitering munition with non-circular body and body-airfoil-empennage combination are calculated numerically at Ma=0.4 based on multi-griddings patching technology,in the range of angle of attack-4°-10°,and the analytical results were compared with those from wind tunnel experiments,they show a good consistency.Analysis of the results showed that the normal force generated by non-circular cross-section missile increases with the angle of attack.At α≥6°,normal force achieved by missile body can take up to 10% of the total lift.Together with the lifting surface,the loitering munitions can provide a better lift to drag ratio,an improved weapon range and a good longitudinal stability.
文摘Loitering munitions are increasingly used in armed conflicts.An extensive database of loitering munitions is developed based on information available in the public domain.This database includes dimensions,weights,and performance parameters such as flight endurance and communication range.Based upon this dataset,6 categories of loitering munitions are identified and statistical trends in the form of equations are provided for each category.The statistical trends are supported by aircraft performance theory tailored to loitering munitions applications.Altogether,the combination of the database,statistical trends and aircraft performance theory can be used to analyse the flight performance and design considerations of new loitering munitions of which only limited non-technical information is available in the public domain such as pictures and news articles.Based on the statistical trends and aircraft performance theory it is concluded that for long range applications,the preferred design solution is the conventional configuration.The cruciform configuration is beneficial in case precision flight path control is of prime importance.The tandem wing configuration combines the benefits of a canister launch and relatively high aspect ratio wings suitable for long range flight.Finally,the delta wing design provides a large internal volume and a high terminal attack airspeed.Two example case studies are included to illustrate the flight performance capabilities of two types of loitering munitions used in the current conflict in Yemen(a long range conventional design and a delta wing configuration).
文摘Cellulose acetate nitrate(CAN) was used as an insensitive energetic binder to improve the insensitive munitions(IM) properties of gun propellants to replace the M1 propellant used in 105 mm artillery charges.CAN contains the energetic nitro groups found in nitrocellulose(NC),but also acetyl functionalities,which lowered the polymer's sensitivity to heat and shock,and therefore improved its IM properties relative to NC.The formulation,development and small-scale characterization testing of several CAN-based propellants were done.The formulations,using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were completed.The small scale characterization testing,such as closed bomb testing,small scale sensitivity,thermal stability,and chemical compatibility were done.The mechanical response of the propellants under high-rate uni-axial compression at,hot,cold,and ambient temperatures were also completed.Critical diameter testing,hot fragment conductive ignition(HFCI) tests were done to evaluate the propellants' responses to thermal and shock stimuli.Utilizing the propellant chemical composition,theoretical predictions of erosivity were completed.All the small scale test results were utilized to down-select the promising CAN based formulations for large scale demonstration testing such as the ballistic performance and fragment impact testing in the105 mm M67 artillery charge configurations.The test results completed in the small and large scale testing are discussed.
文摘Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Phoiobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.). This paper reports that UV-A photoenhanced the toxicity of polynuclear aromatic hydrocarbons, other types of organic compounds, and some transition metals to P. phosphoreum. Coexposure to 400 μw/cm2 for 15 min increased the toxicity of psoralen, α-terthienyl, anthracene, acridine, fluoranthene,TNT, Cu2+, As3+, Ni2, and Cd2+. Phenanthrene was photoenhanced after 30 min coexposure at 400 μw/cm2+, and Mn2+ at 800 μw/cm2 aftef 15 min. Naphthalene was not enhanced at 800 μw/cm2 for 30 min
文摘Mutatox is a new genotoxicity bioassay which uses as the endpoint the bioluminescence produced on reversion of a dark strain of the marine bacterium Vibrio fischeri ±S9.Reversion can occur by several mechanisms, including base substitution, frame-shift, SOS induction, and DNA intercalation. For screening, Mutatox provides many advantages over the Salmonella trphimurium (Ames) assay: it requires minimal sterility, employs a shorter incubation period, and does not require culture maintenance. Eighteen organic chemicals (phenol, polynuclear aromatic hydrocarbons, nitrotoluenes, others), Na3PO4, and 4 genotoxic metals (Cu2+, Ni2+, As3+, Cd2+) were tested. Most of the organic compounds positive in S. typhimurium assays were positive in Mutatox. None of the metals was genotoxic in V. fischeri, possibly due to poor uptake from the saline medium
文摘Cluster munitions release dozens of smaller bomblets that rain deadly ammunition on armored tanks, vegetation and troops, effectively striking broad areas of war zone landscapes in one launch. However, only about 60% of bomblets detonate immediately and those that fail to detonate fall to the ground and can lie dormant for years. The legacy of cluster munitions in Laos from the Second Indochina War is unexploded bomblets across the landscape that unexpectedly detonate years later, injuring and killing children, farmers, and other civilians long after the war is over. In Laos, the United States (US) military operation against the Ho Chi Minh Trail, a network of foot and bicycle paths, waterways, and truck routes along the Laos, Cambodia and Vietnam borders linking North and South Vietnam began in 1959. By the 1960s, as the war escalated, trail traffic was interdicted frequently by CIA and US Air Force using tactical herbicide spraying to defoliate dense vegetation and bombing to disrupt supplies and North Vietnamese troops dispersed along the 16,000-kilometer trail. Unexploded ordinance (UXO), including cluster munitions, from U.S. bombings continued in recent years to detonate, kill, maim and injure Laotians and render agricultural lands too hazardous to cultivate. The primary objectives of this study are to document: 1) the long-term consequences and impacts of the US Air Force bombing of Laos during the Second Indochina War (1959 to 1973);2) the United States removal of unexploded ordnance and cluster munitions;and 3) worldwide relief efforts to help the Laotians maimed by unexploded ordnance and cluster munitions.
文摘Based on the analysis of the flying scheme and flying style of an extended range guided munition(ERGM), the aerodynamic characteristics design standards were put forward. According to the standards, the ERGM aerodynamic configuration was designed, and the wind tunnel experiments were processed. The experimental results show that the configuration has lower drag and good static stability at unguided flying stage. Moreover, the stability, maneuverability, rudder deflection angle and balance angle of attack of the configuration are all reasonably matched at guided flying stage, and the munition with the configuration can glide with larger lift-drag ratio at little balance angle of attack. The experimental results also indicate that the canard can't conduct rolling control when 1.0 ＜ Ma ＜ 1.5, so the ERGM must take rolling flight style with certain limited rolling speed.
