• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.225-227
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• 2011

The geometrically sub-scaled wall-injection test model was employed to visualize interactions of internal flow of a solid rocket motor equipped fin/slot grain and submerged nozzle. Symmetric vortex and circumferential flow patterns were visualized.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.18-25
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• 2006

In order to perform system requirements quickly and accurately, an automatic design program of solid rocket motors(SRM) structure designated as the 'ProDes software' has been developed and verified. from given system design criteria and constraints, it has the capabilities to design, analysis, simulation and drawing process to greatly reduce the over 'design cycle time' and manpower of a project. The conception of the program is modular, and calculations are performed step by step allowing parametric design studies and providing final selected design goal. Each configurations of SRM components and joint types composed of various master models is obtained from the data base module of the library. Between the design results of the ProDes software and those of the previous detail design of the established motor showed good agreements.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.517-520
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• 2017

In this paper, we represented the structural design parameter effect on the sealing gap behavior of solid rocket motor case and nozzle connection under penetrated pressure through the sealing path between insulation rubber and the ablative FRP bonded on the inside convergent wall of nozzle. It is important to keep the good sealing capacity during all the combustion time of SRM. To achieve the crucial role of sealing system of SRM, designers must consider design factors for stable sealing clearance gap as the nearly unchanged initial design state as possible for sufficient compression rate of O-ring under sealing gap pressure.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.3
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• pp.31-39
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• 2011

The flowfield in a solid rocket motor was simulated at the wall-injection test model, which has a fin-slot grain and submerged nozzle, and visualized by a smoke-wire. The high speed CCD camera captured the visualized images around the nozzle inlet through the grain center port. The vortical tube structure and circumferential flow patterns at the nozzle throat were visualized. The radial momentum transfer caused by the shear-interactions of slot-outlet flow, fin-base flow and grain port flow from upstream worked as the source of these phenomena.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.226-234
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• 2008

Grain design has always been a vital and integral part of Solid Rocket Motor(SRM) design. Basing on the design objectives set by the system designer, the SRM designer has many options available for selecting the Grain configuration. Many of the available configurations may fulfill the required parameters of volumetric loading fraction, web fraction & Length to diameter ratios and produce internal ballistic results that may be in accordance to the design objectives. However, for any given set of design objectives, it is deemed necessary that best possible configuration be selected, designed and optimized. Hence optimal results of all applicable configurations are vital to be attained in order to compare and finalize the design that will produce most efficient performance. Generally the engineers pay attention and have skills on a specific grain configuration. The designing methodologies and computer codes available usually focus on single grain configuration may it be Star, Wagon Wheel or slotted tube. Hardly one can find a software or a design methodology where all such configurations can be worked on jointly and not only adequate designs be found but optimal solutions reached by applying an optimization method to find final design best suited for any design objective. In the present work design requirements have been set, grain configurations have been selected and their designing has been conducted. The internal ballistic parameters have been calculated and after finding the preliminary design solutions, the optimal solutions have been found. In doing so, software has been developed comprising of computer programs for designing the 2D grains including Star, Wagon Wheel and Slotted Tube configurations. The optimization toolbox of Matlab Fmincon has been used for getting optimal solutions. The affects of all the independent geometric design variables on the optimized solutions have been analyzed. Based on results attained from Optimization Method, an in depth comparison of Grain Configurations and analysis of performance prediction outputs have been conducted to come to conclusion as to which grain configuration is ideal for the current design requirement under study.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.2
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• pp.29-35
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• 2011

The behaviors of combustion-induced internal flows of SRM equipped with fin-slot grain and submerged nozzle are very complex and diverse. Cold air-flow tests for 2D and 3D scale models of SRM have been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tubes also has been visualized through employing various light source and recording directions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.181-185
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• 2010

The behavior of combustion-induced internal flow of SRM equipped with fin-slot grain and submerged nozzle is very complex and diverse. Cold air-flow test for 2D and 3D scale models of SRM has been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tube also has been visualized through employing various light source and recording directions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.293-300
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• 2008

Efficient designing of SRM Grains in the field of Rocketry is still the main test for most of the nations of world for scientific studies, commercial and military applications. There is a strong need to enhance thrust, improve the effectiveness of SRM and reduce mass of motor and burning time so as to allow the general design to increase the weight of payload/on board electronics. Moreover burning time can be increased while keeping the weight of the propellant and thrust in desired range, so as to give the time to control / general design group in active phase for incorporating delayed cut off if required. A mathematical design, optimization & analysis technique for Slotted Tube Grain has been discussed in this paper. In order to avoid the uncertainties that whether the Slotted Tube grain configuration being designed is best suited for achieving the set design goals and optimal of all the available designs or not, an efficient technique for designing SRM Grain and then getting optimal solution is must. The research work proposed herein addresses and emphasizes a design methodology to design and optimize Slotted Tube Grain considering particular test cases for which the design objectives and constraints have been given. In depth study of the optimized solution have been conducted thereby affects of all the independent parametric design variables on optimal solution & design objectives have been examined and analyzed in detail. In doing so, the design objectives and constraints have been set, geometric parameters of slotted tube grain have been identified, performance prediction parameters have been calculated, thereafter preliminary designs completed and finally optimal design reached. A Software has been developed in MATLAB for designing and optimization of Slotted Tube grains.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.2
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• pp.8-14
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• 2008

Solid Rocket Motor(SRM) has advantages such as - high specific impulse, operational safety and simplicity in design and manufacturing process but thrust magnitude can't be controlled. For studying of pintle nozzle that can control the thrust magnitude of SRM, cold flow test and numerical analysis about needle type pintle shape were performed and results were presented in this paper. As the results of this study, pintle tip's shape and nozzle contour were important design parameters because thrust performance and variable thrust range of pintle nozzle depend on them. Especially, the thrust of needle typed pintle nozzle adopted in this test was predicted 13% higher than normal nozzle without pintle.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.289-294
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• 2007

Solid Rocket Motor(SRM) has advantages such as - high specific impulse, operational safety and simplicity in design and manufacturing process, but thrust magnitude can't be controlled. For studying of pintle nozzle that can control the thrust magnitude of SRM, cold flow test and numerical analysis about needle type pintle shape were performed and results were presented in this paper. As the results of this study, pintle tip's shape and nozzle contour were important design parameters because thrust performance and variable thrust range of pintle nozzle depend on them. Especially, the thrust of needle typed pintle nozzle adopted in this test was predicted 13% higher than normal nozzle without pintle.