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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Propulsion Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Propulsion Engineers
Editor in Chief :
Volume & Issues
Volume 4, Issue 4 - Dec 2000
Volume 4, Issue 3 - Sep 2000
Volume 4, Issue 2 - Jun 2000
Volume 4, Issue 1 - Mar 2000
Selecting the target year
The Effect of Silane Compound on the Cure Reaction and Mechanical Properties of PEG, PCP Binder for Propellant
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 1~5
The silane compounds as a coupling agent have been used in the propellant in order to enhance the mechanical property and lower the viscosity. They showed great effects in the PEG propellant. In PCP propellant, however, the silane compounds not only made a severe cure problem but also deteriorated the mechanical property. In this study, TESPN as a silane compound was applied in PEG and PCP binder for finding above factors. The main reason was that the main chains of PCP were broken due to the trans-esterification reaction of ester groups in PCP and alchol which was produced by reacting silane compounds and moisture in the solution of liquid binder.
A Study on the Flow Control for Stable Combustion of Liquid Rocket
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 6~11
In the pressurized propellant feed system of liquid rocket, feed pressure is decided chamber pressure of normal combustion state. However, during ignition period the initial chamber pressure is atmosphere. So, it may have overflow, hard-start and even critical damage of engine. This paper proposes an improved propellant feed system for the stable combustion of liquid rocket. Hot test were already performed to verify the presented propellent feed system. The proposed propellant feed system uses two steps - pre and main combustion - to prevent large pressure increase and uses cavitating venturis for stable flow rate in whole combustion. This system feeds the flow rate lesser than the designed flow rate, so combustion pressure reached pre-combustion pressure. Cavitating venturis offer unique flow control capabilities at normal and abnormal combustion state, because flow rate is solely dependent on upstream absolute pressure and fluid properties, but independent on downstream condition.
Ignition Transient Mechanism in an Entire Integrated Rocket Ramjet Engine
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 12~20
The numerical analysis, including chemical reaction of an entire ramjet engine is studied to understand the ignition transient mechanism and the dynamic characteristics of the Integrated Rocket Ramjet System comprehensively. Details of how a subsonic combustion environment is established from the supersonic ram air after removal of the inlet port cover, are examined during the ignition transient. Various physical processes are investigated systemically, including ignition, flame propagation, flame dynamics, and vorticity evolution.
Premixture Composition Optimization for the Ram Accelerator Performance Enhancement
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 21~30
Numerical design optimization techniques are implemented for the improvement of the ram accelerator performance. The design object is to find the minimum ram tube length required to accelerate projectile from initial velocity
to target velocity
. The premixture is composed of
and the mole numbers of these species are selected as design variables. The objective function and the constraints are linearized during the optimization process and gradient-based Simplex method and SLP(Sequential Linear Programming) have been employed. With the assumption of two dimensional inviscid flow for internal flow field, the analyses of the nonequilibrium chemical reactions for 8 steps 7 species have been performed. To determined the tube length, ram tube internal flow field is assumed to be in a quasi-steady state and the flow velocity is divided into several subregions with equal interval. Hence the thrust coefficients and accelerations for corresponding subregions are obtained and integrated for the whole velocity region. With the proposed design optimization techniques, the total ram tube length had been reduced 19% within 7 design iterations. This optimization procedure can be directly applied to the multi-stage, multi-premixture ram accelerator design optimization problems.
Low-velocity Impact Damage of a Thick Graphite/Epoxy Case
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 31~38
Pressure vessels by composite materials were damaged sometimes during manufacturing or assembling. The state and the size of damage by low-velocity tests were investigated in this paper. Impactors of various masses and various tup shapes were dropped freely in the range of 120mm height to 700mm height. Compared with hemispherical tup of 12.7mm diameter, for hemispherical tup of 25.4mm diameter the size of surface dent was smaller but the size of delamination was bigger.
Experimental Study on the Unsteady Flow Characteristics of Propellant in the Satellite
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 39~45
A Thruster valve operates to supply fuel into thruster chamber. Very quick on-off operation of thruster valve results in unsteady flow of fuel in the propellant supplying system. Then fuel kinetic force, elastic material of propellant line, compressibility of fuel cause the flow field to pulsate. The pressure oscillation arising from resonance would damage the weak part of the thruster valve and other propellant supplying equipment. Pressure drop and fuel flowrate through propellant suppling system were measured, and pressure oscillation were triggered at the thruster valve inlet.
A Study on the Improvement of Machinability in Hot-Forged Aluminum Alloy Product(Al 7075)
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 46~53
Hot forging of aluminum alloy has the bad machinability due to continuous chip formation caused from the ductility The bad machinability requires a labor and a high cost to produce final products after hot forging. In industrial field, T4 heat treatment is performed to improve the machinability, and the annealing and the cold sizing are followed. In this study, a series of heat treatments are introduced during hot forging operation without T4 heat treatment after forming so that it improves the machinability with reduction of the number of operations and machining cost. Instead of T4 heat treatment, water cooling and air cooling are tried and compared to find out an optimum cooling condition
A Survey on the Droplet Generators and Principle of Droplet Generation
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 54~60
Most droplet generators are based on the Rayleigh's theory of droplet breakup, and various kind of droplet generation devices have been designed in accordance with vibrating method of capillary liquid column. At present, VOAG(Vibrating Orifice Monodisperse Aerosol Generator) is used to generate primary aerosol standards. For the combustion experiments with isolated single droplet, it is found that dripping method or separating method of suspended drop at an end of filament are more effective. Single drops can be separated from continuous streams of droplets by controlling electric charge.
A Study on Steady-state and Transient Performance Simulation of Turboprop Engine(PT6A-62)
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 2, 2000, Pages 61~70
The performance simulation program on the turboprop engine(PT6A-62), which is a main engine of the first trainer KT-1 in republic of Korea, was developed. Characteristics of engine components were required for the steady-state performance analysis including on and off design point analysis. In most cases, these were substituted for what scaled from well known engine components characteristics with the scaling law. The developed program was compared with CASTURB program which is well known for the simulation performance analysis, such as analysis results of mass flow rate, compressor pressure ratio, fuel flow rate, power, specific fuel consumption ratio and turbine inlet temperature in the following four cases, to evaluate whether the developed program is acceptable or not. The first case was the sea level static standard condition and other cases were considered with various flight Mach numbers, altitudes. After verifying the developed program, the partload performance analysis was carried out. Transient performance analysis for various fuel schedules were performed. When the fuel step increase of 0.1sec was performed, the overshoot of the compressor turbine inlet temperature occurred. However, the fuel ramp increase for longer than 0.1sec time was performed, the overshoot could be eliminated.