http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
한조영,백승욱 대한기계학회 1995 대한기계학회논문집 Vol.19 No.9
The ignition phenomena of a solid fuel plate of polymethyl-methacrylate(PMMA), which is vertically positioned and exposed to a thermal radiation source, is numerically studied here. A two-dimensional transient model includes such various aspects as thermal decomposition of PMMA, gas phase radiation absorption, gas phase chemical reaction and air entrainment by natural convection. Whereas the previous studies considers the problem approximately in a one-dimensional form by neglecting the natural convection, the present model takes account of the two-dimensional effect of radiation and air entrainment. The inert heating of the solid fuel is also taken into consideration. Radiative heat transfer is incorporated by th Discrete Ordinates Method(DOM) with the absorption coefficient evaluated using gas species concentration. The thermal history of the solid fuel plate shows a good agreement compared with experimental results. Despite of induced natural convective flow that induces heat loss from the fuel surface, the locally absorbed radiant energy, which is converted to the internal energy, is found to play an important role in the onset of gas phase ignition. The ignition is considered to occur when the rate of variation of gas phase reaction rate reaches its maximum value. Once the ignition takes place, the flame propagates downward.
영국산 화학추진시스템의 기술이력과 통신해양기상위성 이원추진제 추진시스템
한조영,HAN, Cho Young 항공우주시스템공학회 2008 항공우주시스템공학회지 Vol.2 No.1
The technology relevant to a bipropellant propulsion system is quite new one in Korea, which is being transferred for the first time, with development of COMS propulsion system. It hasn't ever attempted before, and hasn't got any general idea itself as well, in Korea. The technical heritage of UK bipropellant propulsion pertinent to COMS propulsion system is scrutinised mainly. Furthermore the strong possibility of COMS CPS for the moon explorer mission is rationalised on the basis of the history of successful predecessors.
단일추진제 로켓 엔진 어셈블리를 위한 우주 공간에서의 과실 방지 설계
한조영,김정수,Han, Cho-Young,Kim, Jeong-Soo 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.10
An analysis has been performed for active thermal control of the KOMPSAT monopropellant rocket engine assembly, i.e., dual thruster module(DTM). The main efforts of this work have been directed at determining proper heater sizes for propellant valves and catalyst beds necessary to maintain their temperatures within specified temperature ranges under KOMPSAT environment and operational conditions. The TAS incorporated with TRASYS thermal radiation analyzer was used to establish a complete heat transfer model which allows to predict the DTM temperature as a function of time. The thermal analysis has been performed in transient mode to verify the appropriate power for catalyst bed heaters necessary to increase catalyst bed temperature to the required value within a specified period of time. Similar analysis has been executed to validate the heater power for the thermostatically controlled primary and redundant heater circuits used to prevent hydrazine freezing, i.e., single fault. Moreover the effect of the radiative property of thermal control coating of heat shield was examined. Thruster firing condition was also simulated for the heat soakback condition. As a consequence, all thermal analysis results for DTM satisfactorily met the thermal requirements for the KOMPSAT DTM under the worst case average voltage, i.e. 25 volt.
한조영,김정수,이승우,Han, Cho-Young,Kim, Jeong-Soo,Rhee, Seung-Wu 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.1
Thermal design fur satellite propulsion system has been performed. Overall design requirements and the constitution for propulsion system is described. To meet the thermal design requirements, both a primary and a redundant heater circuit, each with two thermostats placed in series, will protect each hydrazine-wetted components, even if one heater circuit fails to operate. Heater power is turned off if any one of these thermostats is opened at its higher setpoint. Thus, even if one thermostat is failed closed, the second thermostat will turn off the heater. All such components shall be insulated with MLI. Propulsion heater sizing based on the constant worst cold case condition is conducted through thermal analysis. All heaters selected fur propulsion components operate to prevent propellant freezing satisfying the thermal requirements for the propulsion subsystem over the worst case average voltage, i.e. 25 volts.