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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
A Numerical Analysis for Plastic Deformation of a Ti Alloy and a study for Shear Band Analysis
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 1~12
This study summarizes the numerical analyses of a Ti alloy deformation under a back extrusion process. Amongst metallic parts in a small propulsion motor case, a Ti-6Al-4V alloy is used extensively. However, the Ti alloy shows a great deal of shear band formation which often leads to a fracture due to a narrow working temperature window. Moreover, the shear band tends to develop over an area where a contact occurs between the hot work piece and the die wall, due to localized cooling. Thus, heating the dies is often required to overcome the deformation localization. Therefore, it becomes necessary to investigate the internal temperature and strain rate distribution during forging process of a Ti alloy. Furthermore, a shear band analysis is peformed using a finite difference scheme and a comparison is made between steel and Ti alloy.
Numerical Analysis of Secondary Injection for Thrust Vector Control on 2-Dimensional Supersonic Nozzle
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 13~21
The advantages of the SITVC (Secondary Injection for Thrust Vector Control) technique over mechanical thrust vectoring systems include a reduction in both the nozzle weight and complexity due to the elimination of the mechanical actuators that are used in conventional vectoring. The optimal operating conditions of SITVC were investigated using in-house developed compressible flow analysis codes. Numerical experiments were used to examine the impact of the thrust vector direction with a variety of injection positions, mass flow rates, and injection angles on the two-dimensional expansion cone of a supersonic nozzle. The computational results showed that the optimal position of the secondary injection, with the maximum deviation angle and side thrust, was where the oblique shock generated by the secondary injection reached the end of the nozzle exit.
Improvement of Design by Structural Test for 750㎾ HAWT Composite Blade
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 22~29
In this study, the 750㎾ scale composite blade for the horizontal axis wind turbine system was designed and manufactured, and it was tested and evaluated by the specific structural test rig. In the test, it was found that local bucklings at the trailing edge of the blade and excessive deflections at the blade tip were happened. In order to solve these problems, the design of blade structure was modified. after improving the design, the abrupt change of deflection at the blade tip was reduced by smooth variation of the spar thickness and the local buckling was removed by extending the web length. The modified design was analyzed by the FEM, the safety and stability of th blade structure.
The Experimental Study on the Lift-off Height due to Momentum Ratio in Swirl-Coaxial Injector
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 30~35
The experimental study on the lift-off height of diffusion flames was conducted to investigate the damage of swirl-coaxial injector used in
/kerosene rocket engine during initial stage of ignition. To investigate the causes of damage and to prevent further damage of the injector, experimental injector was designed and hot fire tests were performed with varying propellant momentum ratio(
) from 1 to 12. In experimental coaxial injector, kerosene is sprayed from the central nozzle with swirl and
sprayed around the kerosene nozzle in the direction parallel to the axis of combustion chamber. Chamber pressure are close to the atmospheric condition. Lift-off height was measured by still images from camcoder and average values were used as data.
Analysis of the Spray Distribution Characterization of Impinging Jet Injectors for Liquid Rockets Using PLIF Technique
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 36~45
Most researches for impinging jet spray have been focused on under-standing the breakup mechanism of a liquid sheet formed by the collision of jets and modeling the spray breakup using experimental data. For this reason, there have been few studies on the characteristics of the spatial spray distribution which affects significantly the combustion efficiency. Hence, we measured the radial distribution of fuel massflux using a like-doublet type injector. Instead of PDPA(Phase Doppler Particle Analyzer) which has been used only for the point measurement of the drop size of spray, PLIF(Planar Laser Induced Fluorescence) technique was developed lot the 2-D measurement of the massflux distribution of spray Indirect photography technique was also used to verify PLIF data.
Numerical Analysis of Fluid Flow in a Regenerative Cooling Passage
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 46~52
A computational analysis has been made on fluid flow in a regenerative cooling Passage for a reduced size liquid rocket engine to predict pressure drop and heat transfer rate in it. The contraction/expansion of the cross sectional area of the passage turn out to increases both the pressure loss and the heat transfer rate of the duct. The changes of the cross sectional area near the nozzle throat are effective to protect the throat which suffers from severe thermal load. Also given is the qualitative characteristics of the performance of the regenerative cooling system due to the variation of coolant flow rate.
Measurement of Stress Intensity Factor Using Strain Gage Methods
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 53~64
Strain gage method is investigated to evaluate the mode I stress intensity factor. Two types of specimens for CT and three point bend specimen are used. Sharp notch of specimens is manufactured by wiring discharge machining. Strain gages signal from the crack tip region are used to calculate stress intensity factors. The results are compared with those of the ASTM E399 method and finite element analysis. The present experimental results coincide well with the data obtained from finite element analysis. Attached position of strain gage should be seriously considered during the application of this method.
A study on the Mechanical Properties of
/LXA Composites by Melt-stirring Method
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 65~73
Casting of metal matrix composites is an attractive process since it offers a wide selection of materials and processing conditions. Among the casting methods, melt-stirring technology is much attractive route in industrial application because it is more simple and inexpensive compared to squeeze casting or powder metallurgy. In the present work, effects of particle size, volume fraction of particles and mg addition on mechanical properties and thermal expansion coefficients of
/LXA composites were studied. It is shown that
particles formed at the interface of
particles and matrix made an important role on mechanical properties. Ultimate tensile strength of most composite materials was not increased. But in the case of 5vol% addition of 16
Particle, Ultimate tensile strength of composite materials with 3wt.% Mg was increased. Volume fraction of reinforcements and mg content were thermal expansion coefficients of composite materials were decreased.
Unsteady Transient Flowfield in an Integrated Rocket Ramjet Engine
H.K. Sung ; Vigor Yang ;
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 74~92
A numerical analysis has been conducted to study the transient flowfield during the transition from the booster to sustainer phase in an integrated rocket ramjet (IRR) propulsion system. Emphasis is placed on the unsteady inlet aerodynamics, fuel/air mixing in an entire ramjet engine during the flow transient phase. The computational geometry consists of the entire IRR engine, including the inlet, the combustion chamber, and the exhaust nozzle. Turbulence closure is achieved using a low-Reynolds-number two-equation model. The governing equations are solved numerically by means of a finite-volume, preconditioned flux-differencing scheme over a wide range of Mach umber. Various important physical processes are investigated systemically, including terminal shock train.
A study on the Structural Stability about the Fan Blade by the Air Excited Forces.
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 93~101
In a gas-turbine engine, fan blades in flow path are confronted with many kinds of loading. The study of the excited force by the wake of struts has proposed and the possibility of fatigue failure about rotating fan blades by the excited force at the steady state is evaluated. Equations of the excited force of wakes has been derived at the steady state and the maximum pressure distributions measured at the transient state are proposed. Dynamic characteristics and the fatigue strength of fan blades by experimental test were obtained. To evaluate HCF(High Cycle Fatigue) damage of fan blades, FEM analysis was performed with a steady state harmonic response, which was followed by high cycle fatigue damage factor from goodman diagram.
Guided Missile Initiation Technologies, Now and Tomorrow
Journal of the Korean Society of Propulsion Engineers, volume 4, issue 1, 2000, Pages 102~108
The comparative evaluation/analysis of the initiation technologies currently being used, and the advanced initiation technologies currently being developed lot the aerospace and defense applications was performed. The evaluation criteria used were the compliance, performance, reliability, safety, and cost. The results clearly indicate that there is no one single initiation technology that will satisfy entire spectrum of initiation system requirements. Each initiation system architecture would require different initiation technologies that will satisfy the overall system performance requirements. However, laser initiation, particularly, the laser diode initiation has been getting more attention in recent years. The laser diode initiation, for most part, eliminates EMI and ESD concerns. In addition, laser diode initiation system can also be designed into relatively small packages, are optically connected systems by very light weight cables, are relatively easily designed to meet variety of initiation system requirements. Due to the these compelling factors, laser diode initiation has potential of becoming common initiation systems for many different aerospace and defense application.