• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.9
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• pp.877-885
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• 2017

This paper is concerned with numerical simulation of a gun-launched projectile considering a rifled gun-tube. Gun-launched conditions induce dynamic behaviors, such as high pressure and high speed rotation. A projectile and its internal electronic components may be damaged in such harsh environments. Hence, it is necessary to perform numerical simulation of a gun-launched projectile to predict its dynamic behaviors and stability. In this work, preceding research studies on gun-launched projectiles are investigated, and the simulation method is developed to rotate the projectile through between its rotating band and a rifled-gun tube. The proposed method is verified by comparison with experimental results, and the dynamic behaviors and stability of the projectile are evaluated under gun-launched conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.611-615
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• 2015

Anti-aircraft gun system is used for low-level air defense system and has more than twin guns with high firing rate in order to maximize the capability of defense. Gun's vibration and bullet's variance has a critical effect on accuracy and hit probability of weapon system such as anti-aircraft gun system with high firing rate. Typical mechanism to reduce the amount of vibration and shock during gun-fire process is very important design factor. In this paper, the suspension characteristics of the vehicle are studied for the improvement of isolating performance of gun firing system with high firing rate. Gun fire test for the vehicle is conducted and computational models using Recurdyn and Adams are created based on test results. Through this study, results of computational analysis are compared with the real test results, which includes type, location and quantity of suspension and gun mechanism are selected for anti-aircraft gun. From the result of this study, we could make basic design and consider the proper component of the system such as suspension and gun spring.

• Defense and Technology
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• no.9 s.235
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• pp.74-85
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• 1998

야포분야는 수적으로 북한군이 아측에 비하여 2.3배의 우위를 점하고 있다. 수적인 열세를 만회하기 위하여 화력의 발사속도를 증대시켜 포 1문의 능력을 극대화해야 한다. 현재의 자주포에 사거리 연장, 발사속도 증대, 반응성을 향상시킨다면 자주포 1문이 같은 운용 병력으로 대략 2문의 효율을 갖게 될 것이다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1992.10a
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• pp.3-7
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• 1992

포는 대체로 정확도와 최대 발사거리 및 최대 발사속도 등에 의해 그 성능 이 표현된다. 그 중에서도 최대 발사속도는 매우 중요한 인자로서 포의 주퇴 복좌 장치의 성능에 의해 직접적으로 영향을 받게 된다. 따라서 포의 최대 발사속도 향상을 위해서는 주퇴복좌 장치의 동특성 해석 능력을 확보하고, 그로부터 주퇴 장치의 설계 변경이 가능하도록 해야 한다. 한편, 주퇴복좌기 의 주퇴특성은 주퇴시 총주퇴저항력이 전주퇴장에 대해서 거의 일정해야만 포신에 전달되는 힘을 최소로 하면서 주퇴시간을 최소로 할 수 있으며 이러 한 설계 개념으로 주퇴복좌기를 설계한다. 그에 따라 주퇴복좌기는 그 내부 가 가변 오리피스 및 조절 로드로 이루어져 주퇴복좌기의 주퇴 저항력을 주 퇴속도 및 주퇴변위에 따라 변화시키도록 되어 있다. 따라서 주퇴복좌기는 필연적으로 강한 비선형 특성을 나타낸다. 이러한 주퇴복좌기를 모델링할 때 에 기존에는 주퇴복좌기내의 모든 유체역학적 요소를 고려하여 모델링하는 기법이 통용되어왔다. 그러나 이러한 모델링은 각 요소의 모델링 오차가 누 적될 위험이 있으므로 정확한 모델링을 보장할 수 없으며, 매우 복잡한 과정 을 거쳐야 한다. 따라서 본 연구에서는 주퇴 완충기 시뮬레이터를 이용한 실 험에 따른 계의 파라미터 예측을 통하여 모델링하는 기법을 시도하여 보았 다.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.64-72
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• 2017

The longitudinal dynamic instability which can occur in the fueling process of a space launch vehicle is called pogo. It is caused by coupling between the fuselage and propulsion system and they would be formed as a closed-loop system. so that the amplitude of the response may increase or decrease. In this paper, a mathematical model which is applicable to the systematic pogo analysis of a general launch vehicle is developed for an example of space shuttle. The formulations are composed of the linearized second-order differential equation for the propulsion system, and of the pressure, weight displacement, and generalized displacement. Those are important parameters for pogo analysis, are derived through eigenvalue analysis. By the formulation suggested in this paper, it is expected that mathematical modeling method of the pogo system can be obtained and systematic pogo stability analysis for any launch vehicle will be enabled.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.443-450
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• 2020

This paper reports a design improvement study to solve the stoppage phenomenon caused by the launch-support device applied to K105A1. The K105A1 is a weapon system equipped with an old 105 mm towed howitzer in a wheeled vehicle, which provides superior maneuverability compared to track equipment. The launch support device serves to withstand fire impact and load. In this way, this device is fixed firmly to the ground in preparation for the shooting mission and is responsible for the critical performance, such as fixing the position of the vehicle. On the other hand, during the field test, a temporary stoppage of the launch support occurred, which caused a problem of not being fixed to the ground. To solve this problem, the cause of failure was analyzed by a replay test and parts inspection. In addition, the operating concept, method, and design were analyzed to derive the cause and solve the problem by changing the parts design. Finally, the performance and firing missions were performed normally by applying the changed design to K105A1. The performance stability and reliability of the launch support device were confirmed, which are expected to be of great assistance in the development of military equipment in the future.

• Defense and Technology
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• no.5 s.267
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• pp.34-41
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• 2001

자동장전장치를 적용하면서 얻게 되는 중요한 장점은 발사속도의 향상이다. 전차에서의 발사속도는 중구경화기나 자주포와 같은 최대발사성능보다는 초탄에 의한 표적파괴 실패시 후속탄의 신속한 재사격 능력이라는 관점이 더 중요하며, 자동장전장치는 이러한 측면에서 수동장전보다 장전속도를 증대시킬 수 있고 특히 기동간에도 정지시와 동일한 후속탄 장전성능을 보장해 줄 수 있다는 점에서 수동장전에 비해 커다란 전력증강 효과를 가져올 수 있다.

• Defense and Technology
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• no.4 s.266
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• pp.34-43
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• 2001

자동장전장치를 적용하면서 얻게 되는 중요한 장점은 발사속도의 향상이다. 전차에서의 발사속도는 중구경화기나 자주포와 같은 최대발사성능보다는 초탄에 의한 표적파괴 실패시 후속탄의 신속한 재사격 능력이라는 관점이 더 중요하며, 자동장전장치는 이러한 측면에서 수동장전보다 장전속도를 증대시킬 수 있고 특히 기동간에도 정지시와 동일한 후속탄 장전성능을 보장해 줄 수 있다는 점에서 수동장전에 비해 커다란 전력증강 효과를 가져올 수 있다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.714-717
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• 2017

Among the factors considered in the design stage of a space launch vehicle using liquid propellant, research has been focused out on the pogo phenomenon, longitudinal dynamic instability. The pogo phenomenon refers to the instability that the longitudinal vibration of the launch vehicle structure causes a change in the pressure and flow rate of the fluids in propulsion system, and this change re-excites the fuselage structure. This mechanism constitutes a closed system to gradually increase the vibration of the launch vehicle. This paper specifically focuses on the dynamic analysis of pressure and flow changes in the propulsion system. Based on the example study of the space shuttle, the acoustic modal analysis of the propulsion system is performed to predict the modes of the supply line causing instability of the fuselage.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.4
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• pp.52-60
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• 2015

Operation area of corps was expanded under military reformation, and extending range of 155 mm howitzer became important issue. New approach is needed to extend range to 80 kim. Ramjet engine is air breathing engine, and it can provide specific impulse several times more than solid rocket motor so that range is extended using same weight of propellant. If the ramjet engine is gun-launched system, it does not require any other booster because muzzle velocity is near Mach 3. Especially solid fuel ramjet (SFRJ) does not have any moving part so that it is favorable for gun-launching system which is under high stress during launching. In this paper, we design air intake, combustion chamber, and nozzle of 155 mm gun launched ramjet propelled artillery shell with inviscid flow assumption. We conduct parameter study to have range more than 80 km, and maximum high explosive volume.