http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Young-Suk Jung(정영석),Kie-Joo Cho(조기주),Seok-Hee Lim(임석희),Gyu-Sik Cho(조규식),Seung-Hyub Oh(오승협),Bershadskiy V.A(베르샤드스키) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
In this paper, The optimum design method of temperature and velocity of the pressurization gas to minimize weight of propellant tank pressurization system on system design of propellant feed system of the liquid propellant rocket was suggested. We considered the influences of parameters of pressurization gas on the efficiency of the thermodynamic processes in the tank and on the design of components as gas tank, heat exchanger and diffuser. We have developed the program for determination of the optimum value of temperature and velocity of pressurization gas at the entrance of tank.
헬륨 버블링 방법을 이용한 액체 추진제 로켓 추진제 탱크의 가압 시스템 분석
정영석(Young Suk Jung),임석희(Seok Hee Lim),조기주(Kie Joo Cho),베르샤드스키(V. A. Bershadskiy) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11
This paper presents an analysis method to predict the temperature of LOX(liquid oxygen) and He(helium) contents in LOX at prepressurization and main pressurization stages using GHe(Gas He) bubbling method for propellants feeding system in rocket. With presented analytical method in this paper, variation of temperature and He contents in LOX are predicted at prepressurization and main pressurization stages in case that GHe bubbling method is used in pressurization system of the 2nd stage. Computer simulations are accompanied in conditions of temperature(288K) and mass flowrate(0.02㎏/sec) of injected GHe at prepressurization stage and in conditions of controlled pressure of tank(4bar) and fixed mass flowrate of fed LOX to engine at main pressurization stage.
Optimal Conditions for Thermal Control of LOX using GHe Bubbling Method
Young-Suk Jung(정영석),Seok-Hee Lim(임석희),Gyu-Sik Cho(조규식),Kie-Joo Cho(조기주),V.A. Bershadskiy(베르샤드스키),Seung-Hyub Oh(오승협) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
In this paper, the algorithm for calculating the thermophysical parameters of LOX in tank at the step of LOX thermal conditioning system using GHe bubbling during pre-launch operation is presented. The algorithm is based on a physical-mathematical models which integrally consider the characteristics and intensity of heat and mass transfer in LOX of the propellant tank and the experimental models which are used for the description of intensity of heat and mass transfer and the change of composition of gas and liquid phases in LOX. With the developed algorithm, the transient analysis of thermal conditioning system is executed on each condition as a temperature of injected GHe and pressure of tank, and the optimal conditions are proposed for an efficient thermal conditioning system using GHe bubbling.
정영석 ( Young-suk Jung ) 국군의무사령부 2014 대한군진의학학술지 Vol.45 No.1
Objective: The purpose of this study is to examinate the prevalence of periodontitis in naval soldiers. Methods: 100 soldiers were particiated in this study. Periodontal examinations including pocket depth, gingival recession and bleeding on probing excepting for 3rd molar were carried by one examiner. Results: The prevalence of periodontitis was 60% in included samples and the participants with severe periodontitis were 13%. Most of participants have buccal gingival recession and periodontal pocket over 4mm. Gingival bleeding was 35% in all examined site. Conclusion: Many soldiers are suffered from periodontitis. It is necessary to provide proper dental treatment for soldiers with periodontitis.