• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.1046-1052
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which was operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreased the thermal load and strain of the cooling channel structure. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.802-807
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• 2007

Elastic-plastic structural analysis for regenerative cooling chamber of gas generator was performed. Uniaxial tension test was also conducted for STS316L at room and high temperature conditions to get the material data necessary for the structural analysis of the chamber which is operated under thermal load and high internal pressure. Physical properties including thermal conductivity, specific heat and thermal expansion data were also measured. The structural analysis for four different types of regenerative cooling chamber of gas generator revealed that increased cooling performance decreases the thermal load and strain of the cooling channel. The results propose that in order for the regenerative cooling gas generator chamber to have high structural stability with endurance to high mechanical and thermal loads, it is important for the chamber to be designed to have high cooling performance.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.39-47
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• 2005

The structural analysis and water pressure tests are performed for liquid rocket thrust chamber regenerative cooling channel specimens at room temperature condition. Material properties of copper alloy to be used in the elastic-plastic structural analysis are obtained by uniaxial tension test at room temperature. The plate-type cooling channel specimens are manufactured and performed water pressure test to verify the analysis results. The results of elastic-plastic structural analysis and water pressure test show resonable agreements though with minor differences and it is revealed that structural stability of regenerative cooling channel is highly affected by the manufacturing tolerances due to very thin cross-sectional thickness of the cooling channel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.149-152
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• 2008

Effects of chamber configuration on combustion characteristic velocity of full-scale combustion chamber for 30-tonf-class liquid rocket engine were studied. The configurations of combustion chamber are ablative and channel cooling chamber (${\varepsilon}$=3.2) which have detachable mixing head, and single body regenerative cooling chamber which has nozzle expansion ratio of 3.5 and 12, respectively. The combustion chambers have chamber pressure of 53${\sim}$60 bar and propellant mass flow rate of 89 kg/s, and the injectors of all combustion chamber have recess number 1.0 and double-swirl characteristics. The hot firing test results at design point show that the combustion characteristic velocity of the regenerative cooling chamber which has nozzle expansion ratio of 12 is higher than that of other combustion chambers. The reasons for the above result are the increases of combustion pressure and enthalpy of kerosene which is heated due to cooling of the chamber wall before injection into the combustion field.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.151-155
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• 2006

Elastic-viscoplastic structural analysis is performed for regenerative cooling chamber of liquid rocket thrust chamber using Bodner-Partom visco-plastic model. Strain rate test was also conducted for a copper alloy at various temperatures in order to get material constants of visco-plastic model used in the structural analysis. Material constants of visco-plastic model were obtained from strain rate test results and visco-plsstic model was incorporated into finite element program, Marc, by means of user subroutine. The structural analysis results indicate that the deformation of cooling channel is mostly caused by thermal loading rather than pressure loading and confirmed structural stability of the cooling channel under operating condition.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.4
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• pp.69-76
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• 2006

Elastic-viscoplastic structural analysis has been performed for regenerative cooling chamber of liquid rocket thrust chamber using Bodner-Partom visco-plastic model. Strain rate test was conducted for a copper alloy at various temperatures in order to get material constants of visco-plastic model used in the structural analysis. Material constants of visco-plastic model were obtained from strain rate test results and visco-plastic model was incorporated into finite element program, Marc, by means of a user subroutine. The structural analysis results indicated that the deformation of cooling channel is mostly caused by thermal loading rather than pressure loading and confirmed structural stability of the cooling channel under the operating condition.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1201-1208
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• 2009

Dome stretching tests and tension tests were performed to evaluate the formability of a copper alloy used for manufacturing the regenerative cooling chamber. The test specimens were prepared to investigate the effect of heat treatment and direction of specimens on the formability. The test results show that forming limit values are increased by the heat treatment of the material but the variation of the forming limit values by manufacturing direction is negligible compared to the heat treatment effect, and forming limit values are also different according to the test methods. These results indicate that the high temperature heat treatment of the material before bulging is a very important process to deform the inner cylindrical structure of the regenerative cooling chamber into a nozzle shape by the bulging process without necking or fracture and the test methods also have a great effect on a evaluation of the formability. The forming limit diagram obtained in this study would be utilized to the design of regenerative cooling chamber nozzles.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.6
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• pp.8-16
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• 2009

The development of high-pressure sub-scale combustion chambers is described. A total of four high-pressure sub-scale combustion chambers having either a detachable structure of the mixing head and the chamber or a single welded regenerative cooling structure have been developed. The sub-scale combustion chambers have a chamber pressure of 70 bar and propellant mass flow rate of 5.1~9.1 kg/s. The propellant mass flow rate and the recess number of the injector were changed for the improvement of combustion performance and they were validated through hot firing tests. The design and manufacturing techniques of regenerative cooling channel and film cooling to be applied to the full-scale combustion chamber were adopted through the present development and verified.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.134-138
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• 2005

The structural analysis and water pressure test of regenerative liquid rocket thrust chamber cooling channel specimens are performed at room temperature. material properties of copper alloy are obtained by uniaxial tension test at room temperature and used of elastic-plastic structural analysis. The plate type of cooling channel specimen are manufactured and performed water pressure test in order to confirm the analysis results. The differences between results of elastic-plastic analysis and that of water pressure test of cooling channel specimen are small and find that manufacturing process affect the structural stability of cooling channel very much because cooling channel thickness is small

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.396-405
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• 2009

The experimental research was conducted to setup a performance prediction logic for the regenerative cooling system on a small scale liquid rocket engine using kerosene and LOX. Total heat flux of the combustion gas side was determined for the flow rate of the coolant, combustion pressure using the calorimeter thrust chamber. Based on the experimental investigation, a performance prediction scheme for the regenerative cooling system is setup in our own way. A performance prediction logic for the regenerative cooling system has been developed by the correction scheme of the combustion gas side. The key parameters determining the temperature limitation of the coolant are the mass flow rate of the coolant and the length of the combustion chamber and the nozzle. And the parameters to control the limitation of the usable wall temperature are the number of channels and wall thickness.