Semisubmersible naval ships are versatile military crafts that combine the advantageous features of high-speed planing crafts and submarines.At-surface,these ships are designed to provide sufficient speed and maneuver...Semisubmersible naval ships are versatile military crafts that combine the advantageous features of high-speed planing crafts and submarines.At-surface,these ships are designed to provide sufficient speed and maneuverability.Additionally,they can perform shallow dives,offering low visual and acoustic detectability.Therefore,the hydrodynamic design of a semisubmersible naval ship should address at-surface and submerged conditions.In this study,Numerical analyses were performed using a semisubmersible hull form to analyze its hydrodynamic features,including resistance,powering,and maneuvering.The simulations were conducted with Star CCM+version 2302,a commercial package program that solves URANS equations using the SST k-ωturbulence model.The flow analysis was divided into two parts:at-surface simulations and shallowly submerged simulations.At-surface simulations cover the resistance,powering,trim,and sinkage at transition and planing regimes,with corresponding Froude numbers ranging from 0.42 to 1.69.Shallowly submerged simulations were performed at seven different submergence depths,ranging from D/LOA=0.0635 to D/LOA=0.635,and at two different speeds with Froude numbers of 0.21 and 0.33.The behaviors of the hydrodynamic forces and pitching moment for different operation depths were comprehensively analyzed.The results of the numerical analyses provide valuable insights into the hydrodynamic performance of semisubmersible naval ships,highlighting the critical factors influencing their resistance,powering,and maneuvering capabilities in both at-surface and submerged conditions.展开更多
Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of fligh...Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].展开更多
Naval Vessels Combat System is a kind of complex system.The modeling of combat system has become hot issues in the past years.This paper proposed a new method to establish models of combat system based on the theory o...Naval Vessels Combat System is a kind of complex system.The modeling of combat system has become hot issues in the past years.This paper proposed a new method to establish models of combat system based on the theory of Complex Network.The method of modeling considered the operational entities as nodes.It considered flow of information,substance and energy as edges in a network.The research also carries on a simulation to prove the applicability.Ultimately,the paper concluded that this method is applicable and accurate.展开更多
Since the 18th National Congress of Chinese Communist Party,the great call for building a maritime power and a power⁃ful military force has set higher standards for Navy’s development and the application of strategie...Since the 18th National Congress of Chinese Communist Party,the great call for building a maritime power and a power⁃ful military force has set higher standards for Navy’s development and the application of strategies.As a maritime military force,the navy bears considerable responsibilities of safeguarding territorial sovereignty,maritime rights and interests with security and development as core mission,and defending the role and image of China as a major county in the world.This paper analyzes and studies naval officers’global competence development from three aspects,and discusses the significance and recommendations of strengthening the development of naval cadets’global competence in cooperation and exchange guided by“Belt and Road”Initia⁃tive(BRI).展开更多
The test shell without projectile belt is widely used in the teaching,inspection and maintenance of modern automatic naval guns.In order to ensure the normal work of each mechanism,it is very important to design the b...The test shell without projectile belt is widely used in the teaching,inspection and maintenance of modern automatic naval guns.In order to ensure the normal work of each mechanism,it is very important to design the buffer and limit of the test shell during the process of entering the bore.Taking a certain type of medium caliber naval gun as the research object,the design of colloidal fluid damper and cartridge lock was proposed to ensure the reliability of entering the bore and closing the breechblock.By combining the simulation methods of computational fluid dynamics(CFD)and multibody system dynamic(MBD),it was analyzed whether the structural design can meet the engineering requirements.The research results show that the colloidal fluid damper can dissipate a large amount of kinetic energy of the shell,and the cartridge lock can limit the rebound movement.The combination of the two ensures the smooth process of closing the breechblock.The research provides a design method for the process of the test shell entering the bore,and provides theoretical support for the feasibility of the method.展开更多
Combined with naval vessel practical antisubmarine equipment of towed linear array sonar,a mathematical model of naval vessel localization for submarine based on bearing measurement was built,and localization algorith...Combined with naval vessel practical antisubmarine equipment of towed linear array sonar,a mathematical model of naval vessel localization for submarine based on bearing measurement was built,and localization algorithm was given to solve submarine movement parameters.Localizaiton errors were analyzed.Based on localization model and algorithm,simulations were done to study the effect of factors such as initial distance between submarine and the naval vessel,submarine initial bearing angle measured by the naval vessel and submarine course on localization performance,and then simulation results were given and analyzed.The results have practical value to instruct real antisubmarine.Simulation results show that different target movement situations have great influence on sonar detection and localization performance,so the reasonable choice of sonar position and detection bearing according to the target movement situation can improve sonar detection and localization performance to some degree.展开更多
Naval grade high strength low alloy(HSLA) steels can be easily welded by all types of fusion welding processes. However, fusion welding of these steels leads to the problems such as cold cracking, residual stress, dis...Naval grade high strength low alloy(HSLA) steels can be easily welded by all types of fusion welding processes. However, fusion welding of these steels leads to the problems such as cold cracking, residual stress, distortion and fatigue damage. These problems can be eliminated by solid state welding process such as friction stir welding(FSW). In this investigation, a comparative evaluation of mechanical(tensile, impact,hardness) properties and microstructural features of shielded metal arc(SMA), gas metal arc(GMA) and friction stir welded(FSW) naval grade HSLA steel joints was carried out. It was found that the use of FSW process eliminated the problems related to fusion welding processes and also resulted in the superior mechanical properties compared to GMA and SMA welded joints.展开更多
Aiming at the problems of unreliable data transmission,poor steadiness,nonsupport of complex data types,direct couple between data transmission and exchange,a high-level method based on advanced message queuing protoc...Aiming at the problems of unreliable data transmission,poor steadiness,nonsupport of complex data types,direct couple between data transmission and exchange,a high-level method based on advanced message queuing protocol( AMQP) is proposed to integrate naval distributed tactical training simulation system after serious consideration with current information exchange features of military combat system. Transferring layer in traditional user datagram protocol is implemented by publishing and subscribing scheme of message middleware. By creating message model to standardize message structure,integration architecture is formulated to resolve potential information security risks from inconsistent data type and express data transmission. Meanwhile,a communication model is put forward based on AMQP,which is in the center position of the whole transmission framework and responsible for reliably transferring battlefield data among subsystems. Experiments show that the method can accurately post amounts of data to the subscriber without error and loss,and can get excellent real-time performance of data exchange.展开更多
The risks in development of navy vessels were explored, The resources of technical risk in the design and development of vessels were mentioned, It was pointed that technical risk dominated the other risk components. ...The risks in development of navy vessels were explored, The resources of technical risk in the design and development of vessels were mentioned, It was pointed that technical risk dominated the other risk components. Based on the writers＇ understanding and experience from risk analysis and risk ,nanagement to the development of a navy vessel, four measure indexes of technical risk were presented. The decision criteria and the rules corresponding to the indexes were estahlished by the statistic information,展开更多
Dear Editor,Recent advances in military technology have led to the development of sophisticated and intelligent weapons, which increase mortality and morbidity. Since the advent of highexplosion weapons, "shock w...Dear Editor,Recent advances in military technology have led to the development of sophisticated and intelligent weapons, which increase mortality and morbidity. Since the advent of highexplosion weapons, "shock wave" has surpassed "shrapnel" and become the most important injurious component in conventional combat. Traumatic brain injury(TBI) is a leading cause of disability and death among military personnel and civilians during wartime[1]. Clinically, its symptoms and indications vary depending on the location and severity of the injury. The most frequently observed symptoms included altered consciousness and local dysfunction.展开更多
BACKGROUND Specific pulmonary infection could seriously threaten the health of pilots and their companions.The consequences are serious.We investigated the clinical diagnosis,treatment,and medical identification of sp...BACKGROUND Specific pulmonary infection could seriously threaten the health of pilots and their companions.The consequences are serious.We investigated the clinical diagnosis,treatment,and medical identification of specific pulmonary infections in naval pilots.CASE SUMMARY We analyzed the medical waiver and clinical data of four pilots with specific pulmonary infections,who had accepted treatment at the Naval Medical Center of Chinese People’s Liberation Army between January 2020 and November 2021,including three cases of tuberculosis and one of cryptococcal pneumonia.All cases underwent a series of comprehensive treatment courses.Three cases successfully obtained medical waiver for flight after being cured,while one was grounded after reaching the maximum flight life after being cured.CONCLUSION Chest computed tomography scanning should be used instead of chest radiography in pilots’physical examination.Most pilots with specific pulmonary infection can be cured and return to flight.展开更多
Summary of results from a high - resolution pan - Arctic ice - ocean model are presented for the northern North Pacific, Bering, Chukchi, and Beaufort seas. The main focus is on the mean circulation, communication fro...Summary of results from a high - resolution pan - Arctic ice - ocean model are presented for the northern North Pacific, Bering, Chukchi, and Beaufort seas. The main focus is on the mean circulation, communication from the Gulf of Alaska across the Bering Sea into the western Arctic Ocean and on mesoscale eddy activity within several important ecosystems. Model results from 1979 -2004 are compared to observations whenever possible. The high spatial model resolution at 1/12o （or -9 - km） in the horizontal and 45 levels in the vertical direction allows for representation of eddies with diameters as small as 36 km. However, we believe that upcoming new model integrations at even higher resolution will allow us to resolve even smaller eddies. This is especially important at the highest latitudes where the Rossby radius of deformation is as small as 10 km or less.展开更多
BACKGROUND Recently,two naval pilots in a two-seat trainer jet were forced to eject urgently due to sudden mechanical failure during night-time training.They were both successfully rescued and sent to the hospital for...BACKGROUND Recently,two naval pilots in a two-seat trainer jet were forced to eject urgently due to sudden mechanical failure during night-time training.They were both successfully rescued and sent to the hospital for emergency treatment.In this study,we investigate their ejection injuries and recovery process.CASE SUMMARY We analyzed the clinical data of the traumatic condition and recovery process from ejection injuries of two pilots who ejected from a failed trainer jet and survived.After being successfully rescued and sent to the hospital,they were diagnosed with multiple ejection injuries,including eye trauma,limb bone and joint injury,rib and spine injury,and so on.Both cases underwent fluid replacement,acid suppression,nutritional support,hemostasis,bone metabolism improvement,phlegm elimination,psychological measurement,blood circulation promotion and detumescence,physical therapy,and external fixation with braces for 1 mo before being discharged from hospital.They then recuperated in a sanatorium for 2 mo,and the related laboratory tests and supplementary examinations show that they recovered from all the above injuries.After successfully passing the psychological test and physical examination,they returned to flight duty 3 mo after ejection.CONCLUSION The causes and conditions of ejection injury in the pilots were very complex.Although they finally recovered quickly and were released,it also serves as a reminder that attention should be paid to pilots’ejection and parachute training in order to significantly reduce ejection injury and improve the ejection success rate.In addition,air defense support personnel should strengthen search and rescue and on-site emergency measures,and locate and rescue pilots in distress as early as possible to reduce subsequent injuries.展开更多
The Western Pacific Naval Symposium （WPNS） was founded in 1988 and is the only multilateral mechanism in the Asia Pacific region that pushes forward cooperation among naval forces.1 Even though it already has a 26-y...The Western Pacific Naval Symposium （WPNS） was founded in 1988 and is the only multilateral mechanism in the Asia Pacific region that pushes forward cooperation among naval forces.1 Even though it already has a 26-year history, the WPNS has not attracted enough attention, and very little information has been released on its activities among naval forces,展开更多
文摘Semisubmersible naval ships are versatile military crafts that combine the advantageous features of high-speed planing crafts and submarines.At-surface,these ships are designed to provide sufficient speed and maneuverability.Additionally,they can perform shallow dives,offering low visual and acoustic detectability.Therefore,the hydrodynamic design of a semisubmersible naval ship should address at-surface and submerged conditions.In this study,Numerical analyses were performed using a semisubmersible hull form to analyze its hydrodynamic features,including resistance,powering,and maneuvering.The simulations were conducted with Star CCM+version 2302,a commercial package program that solves URANS equations using the SST k-ωturbulence model.The flow analysis was divided into two parts:at-surface simulations and shallowly submerged simulations.At-surface simulations cover the resistance,powering,trim,and sinkage at transition and planing regimes,with corresponding Froude numbers ranging from 0.42 to 1.69.Shallowly submerged simulations were performed at seven different submergence depths,ranging from D/LOA=0.0635 to D/LOA=0.635,and at two different speeds with Froude numbers of 0.21 and 0.33.The behaviors of the hydrodynamic forces and pitching moment for different operation depths were comprehensively analyzed.The results of the numerical analyses provide valuable insights into the hydrodynamic performance of semisubmersible naval ships,highlighting the critical factors influencing their resistance,powering,and maneuvering capabilities in both at-surface and submerged conditions.
基金supported by the Military Medical Science and Technology Youth Cultivation Program of the Chinese PLA(17QNP023)the Key Projects of Medical Service Scientific Research of the Navy Medical Center(20M2302)the Military Logistics National Military Standard General Project of Chinese PLA(BHJ22B002).
文摘Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].
基金supported by Science Foundation of Dalian Naval Academy
文摘Naval Vessels Combat System is a kind of complex system.The modeling of combat system has become hot issues in the past years.This paper proposed a new method to establish models of combat system based on the theory of Complex Network.The method of modeling considered the operational entities as nodes.It considered flow of information,substance and energy as edges in a network.The research also carries on a simulation to prove the applicability.Ultimately,the paper concluded that this method is applicable and accurate.
文摘Since the 18th National Congress of Chinese Communist Party,the great call for building a maritime power and a power⁃ful military force has set higher standards for Navy’s development and the application of strategies.As a maritime military force,the navy bears considerable responsibilities of safeguarding territorial sovereignty,maritime rights and interests with security and development as core mission,and defending the role and image of China as a major county in the world.This paper analyzes and studies naval officers’global competence development from three aspects,and discusses the significance and recommendations of strengthening the development of naval cadets’global competence in cooperation and exchange guided by“Belt and Road”Initia⁃tive(BRI).
基金This work wasp artially sponsored by Naval University of Engineering.
文摘The test shell without projectile belt is widely used in the teaching,inspection and maintenance of modern automatic naval guns.In order to ensure the normal work of each mechanism,it is very important to design the buffer and limit of the test shell during the process of entering the bore.Taking a certain type of medium caliber naval gun as the research object,the design of colloidal fluid damper and cartridge lock was proposed to ensure the reliability of entering the bore and closing the breechblock.By combining the simulation methods of computational fluid dynamics(CFD)and multibody system dynamic(MBD),it was analyzed whether the structural design can meet the engineering requirements.The research results show that the colloidal fluid damper can dissipate a large amount of kinetic energy of the shell,and the cartridge lock can limit the rebound movement.The combination of the two ensures the smooth process of closing the breechblock.The research provides a design method for the process of the test shell entering the bore,and provides theoretical support for the feasibility of the method.
文摘Combined with naval vessel practical antisubmarine equipment of towed linear array sonar,a mathematical model of naval vessel localization for submarine based on bearing measurement was built,and localization algorithm was given to solve submarine movement parameters.Localizaiton errors were analyzed.Based on localization model and algorithm,simulations were done to study the effect of factors such as initial distance between submarine and the naval vessel,submarine initial bearing angle measured by the naval vessel and submarine course on localization performance,and then simulation results were given and analyzed.The results have practical value to instruct real antisubmarine.Simulation results show that different target movement situations have great influence on sonar detection and localization performance,so the reasonable choice of sonar position and detection bearing according to the target movement situation can improve sonar detection and localization performance to some degree.
基金The Director,Naval Material Research Laboratory(NMRL),Ambernath for financial support through CARS project No:G8/15250/2011 dated29.02.2012
文摘Naval grade high strength low alloy(HSLA) steels can be easily welded by all types of fusion welding processes. However, fusion welding of these steels leads to the problems such as cold cracking, residual stress, distortion and fatigue damage. These problems can be eliminated by solid state welding process such as friction stir welding(FSW). In this investigation, a comparative evaluation of mechanical(tensile, impact,hardness) properties and microstructural features of shielded metal arc(SMA), gas metal arc(GMA) and friction stir welded(FSW) naval grade HSLA steel joints was carried out. It was found that the use of FSW process eliminated the problems related to fusion welding processes and also resulted in the superior mechanical properties compared to GMA and SMA welded joints.
基金Supported by the National Natural Science Foundation of China(No.61401496)
文摘Aiming at the problems of unreliable data transmission,poor steadiness,nonsupport of complex data types,direct couple between data transmission and exchange,a high-level method based on advanced message queuing protocol( AMQP) is proposed to integrate naval distributed tactical training simulation system after serious consideration with current information exchange features of military combat system. Transferring layer in traditional user datagram protocol is implemented by publishing and subscribing scheme of message middleware. By creating message model to standardize message structure,integration architecture is formulated to resolve potential information security risks from inconsistent data type and express data transmission. Meanwhile,a communication model is put forward based on AMQP,which is in the center position of the whole transmission framework and responsible for reliably transferring battlefield data among subsystems. Experiments show that the method can accurately post amounts of data to the subscriber without error and loss,and can get excellent real-time performance of data exchange.
文摘The risks in development of navy vessels were explored, The resources of technical risk in the design and development of vessels were mentioned, It was pointed that technical risk dominated the other risk components. Based on the writers＇ understanding and experience from risk analysis and risk ,nanagement to the development of a navy vessel, four measure indexes of technical risk were presented. The decision criteria and the rules corresponding to the indexes were estahlished by the statistic information,
文摘Dear Editor,Recent advances in military technology have led to the development of sophisticated and intelligent weapons, which increase mortality and morbidity. Since the advent of highexplosion weapons, "shock wave" has surpassed "shrapnel" and become the most important injurious component in conventional combat. Traumatic brain injury(TBI) is a leading cause of disability and death among military personnel and civilians during wartime[1]. Clinically, its symptoms and indications vary depending on the location and severity of the injury. The most frequently observed symptoms included altered consciousness and local dysfunction.
基金Supported by Key Project of Medical Service Scientific Research of Navy Medical Center,No.20M2302.
文摘BACKGROUND Specific pulmonary infection could seriously threaten the health of pilots and their companions.The consequences are serious.We investigated the clinical diagnosis,treatment,and medical identification of specific pulmonary infections in naval pilots.CASE SUMMARY We analyzed the medical waiver and clinical data of four pilots with specific pulmonary infections,who had accepted treatment at the Naval Medical Center of Chinese People’s Liberation Army between January 2020 and November 2021,including three cases of tuberculosis and one of cryptococcal pneumonia.All cases underwent a series of comprehensive treatment courses.Three cases successfully obtained medical waiver for flight after being cured,while one was grounded after reaching the maximum flight life after being cured.CONCLUSION Chest computed tomography scanning should be used instead of chest radiography in pilots’physical examination.Most pilots with specific pulmonary infection can be cured and return to flight.
基金the U.S.National Science Foundation/Shelf-Basin Interactions (SBI) Program for primary support of this researchAdditional support has been provided through other National Science Foundation Office of Polar Program(OPP) grants,the U.S+3 种基金Department of Energy Climate Change Prediction Program(CCPP)National Aeronautics and Space Administration Ocean and Ice ProgramComputer resources were provided by the Arctic Region Supercomputing Center(ARSC) through the U.S.Department of Defense High Performance Computer Modernization Program(HPCMP).
文摘Summary of results from a high - resolution pan - Arctic ice - ocean model are presented for the northern North Pacific, Bering, Chukchi, and Beaufort seas. The main focus is on the mean circulation, communication from the Gulf of Alaska across the Bering Sea into the western Arctic Ocean and on mesoscale eddy activity within several important ecosystems. Model results from 1979 -2004 are compared to observations whenever possible. The high spatial model resolution at 1/12o （or -9 - km） in the horizontal and 45 levels in the vertical direction allows for representation of eddies with diameters as small as 36 km. However, we believe that upcoming new model integrations at even higher resolution will allow us to resolve even smaller eddies. This is especially important at the highest latitudes where the Rossby radius of deformation is as small as 10 km or less.
基金Supported by Key Projects of Medical Service Scientific Research of the Navy Medical Center,No.20M2302.
文摘BACKGROUND Recently,two naval pilots in a two-seat trainer jet were forced to eject urgently due to sudden mechanical failure during night-time training.They were both successfully rescued and sent to the hospital for emergency treatment.In this study,we investigate their ejection injuries and recovery process.CASE SUMMARY We analyzed the clinical data of the traumatic condition and recovery process from ejection injuries of two pilots who ejected from a failed trainer jet and survived.After being successfully rescued and sent to the hospital,they were diagnosed with multiple ejection injuries,including eye trauma,limb bone and joint injury,rib and spine injury,and so on.Both cases underwent fluid replacement,acid suppression,nutritional support,hemostasis,bone metabolism improvement,phlegm elimination,psychological measurement,blood circulation promotion and detumescence,physical therapy,and external fixation with braces for 1 mo before being discharged from hospital.They then recuperated in a sanatorium for 2 mo,and the related laboratory tests and supplementary examinations show that they recovered from all the above injuries.After successfully passing the psychological test and physical examination,they returned to flight duty 3 mo after ejection.CONCLUSION The causes and conditions of ejection injury in the pilots were very complex.Although they finally recovered quickly and were released,it also serves as a reminder that attention should be paid to pilots’ejection and parachute training in order to significantly reduce ejection injury and improve the ejection success rate.In addition,air defense support personnel should strengthen search and rescue and on-site emergency measures,and locate and rescue pilots in distress as early as possible to reduce subsequent injuries.
文摘The Western Pacific Naval Symposium （WPNS） was founded in 1988 and is the only multilateral mechanism in the Asia Pacific region that pushes forward cooperation among naval forces.1 Even though it already has a 26-year history, the WPNS has not attracted enough attention, and very little information has been released on its activities among naval forces,
