• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.145-148
• /
• 2009

A study on ETC(Electrothermal chemical) Guns has been conducted. The existing code of the numerical analysis for the interior ballistics has been extended for ETC Guns. Using this code, the performance analysis of interior ballistics according to the injection patterns of the plasma energy has been fulfilled.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.6
• /
• pp.1-9
• /
• 2015

This paper introduces a zero-dimensional modeling on the plasma generation in electrothermal gun operation. The plasma generator consists of alumina bore and aluminum electrodes which is electrically powered by outer pulse forming network and, traditionally, its numerical simulations have employed time-dependent one-dimensional governing equations. However, by assuming isothermal approximation along the bore and choked bore exit condition, present analysis simplifies the mass and energy equations into zero-dimensional approximation of plasma conditions coupled with mass ablation model and plasma property evaluation. The numerical results show good agreement with the corresponding one-dimensional computations and thus verify the present modeling approach.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.6
• /
• pp.971-976
• /
• 2012

A 150 kJ compact capacitive pulsed power system (CCPPS) capable of delivering electrical energy into an electrothermal chemical (ETC) gun on a vehicle has been studied. The CCPPS provides pulsed electrical energy into a capillary plasma injector which generates plasma of tens of thousands $^{\circ}K$ in temperature and has a nonlinear resistance depending on the current. The design requirements of the CCPPS are as follows: the maximum power of 250 MW, the pulse width of about 0.6 ms, the volume of no more than 0.5 cubic meter, the efficiency of energy transfer over 80 % and the repetition rate of 4~5 times per minute. The constructed CCPPS is composed of four 37.5 kJ capacitor bank modules in parallel to make a trapezoid pulse shape and to satisfy the design requirements. Each module is designed to achieve high reliability, safety, efficiency and energy density to endure severe operating conditions. The results of the performance test on the CCPPS using a 120 mm ETC gun are described.

• Proceedings of the KIEE Conference
• /
• 2001.07c
• /
• pp.1603-1605
• /
• 2001

Eight 300kJ modularized capacitor-banks have been constructed. These modules have been installed and assembled to make a 2.4MJ pulse power system (PPS). This 2.4MJ PPS was developed to be used as a driver of an electrothermal-chemical (ETC) gun. Each capacitor bank has six 22kV, 50kJ capacitors connected in parallel. A triggered vacuum switch (TVS-43) was adopted as a main pulse power-closing switch in each module. The module also contains a crowbar circuit made of three high-voltage diode-stacks, a multi-tap inductor and an energy-dumping resistor. Various current shapes have been formed by a sequential firing of multiple capacitor banks. Resistive dummy load has been used and various combinations of experimental parameters, such as charging voltage, trigger time and inductance, were tested to make flexible current shapes.

• Journal of computational fluids engineering
• /
• v.14 no.1
• /
• pp.70-77
• /
• 2009

In this study, time-dependent numerical analysis was carried out to investigate the plasma jet impingement on a flat plate, and a compressible form of two-dimensional inviscid gas dynamics equations were solved using the flux corrected transport algorithm. The mathematical modeling of Joule heating in the polycarbonate capillary bore and the mass ablation from the bore wall was incorporated in the numerical analysis and the series of computation was performed for three cases depending on the distance of the opposing plate from the capillary exit. The computational results reveal that the presence of the opposing plate does not affect the flow conditions inside the capillary when compared to the case of open-air plasma discharge. In the exterior region, the flow structure shows the typical supersonic underexpanded jet which consists of the strong Mach disk in front of the opposing plate and the barrel shock at the side of the jet. It is found that the shock evolution becomes more quasi-steady when the plate distance decreases. Also, the effects of the distance between the capillary bore exit and the opposing plate on the flow conditions along the opposing plate are investigated and the pressure variation on the plate shows more complicated interaction between the plasma discharge and the opposing plate when the location of plate becomes closer to the capillary exit.