• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.129-135
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• 2008

The 30 tonf-class liquid rocket combustor currently being developed is designed to connect the fuel feeding line at a middle position of the supersonic nozzle in order to reduce both pressure loss in the regenerative cooling passage and overall envelope of the thrust chamber in spite of increase in design complexity. To verify the design of cooling passages including fuel ring, connecting holes, two-directional cooling channels and collectors, numerical analysis has been performed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.9-9
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• 1999

액체로켓 엔진의 분사기와 연소실 설계에 사용될 재생냉각형 칼로리미터의 냉각유로를 설계하였다. 사용할 펌프의 수두는 5기압이며 이로써 끓는점 아래에서 작동할 수 있고 동시에 넓은 냉각 면적을 가지는 유로의 형상을 결정하였다. 유로에서의 압력강하와 온도분포는 전산유동해석에 의하여 구하였고 열부하는 기존의 연소 해석과 1차원해석에 의한 결과를 적용하였다. 해석결과로서 유로의 폭이 4mm에서 2.5mm까지 2단계로 줄었다가 다시 2단계로 늘어나는 냉각유로를 설계하였으며 이 때 높이는 2mm로 일정하게 유지하였다. 유량 변화에 의한 레이놀즈 수는 1.9$\times$$10^4$, 2.4$\times$$10^4$, 2.9$\times$$10^4$이며 세 경우 모두 주어진 펌프수두 이내의 압력강하를 보였으나 온도상승과 성능상의 여유를 고려하여 레이놀즈 수 2.4$\times$$10^4$인 경우를 최종 설계안으로 결정하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.46-52
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• 2000

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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.11
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• pp.1087-1093
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• 2008

Regenerative cooling passage to guarantee the thermal survivability in high performance rocket engine combustors could have complex configurations of the branching/merging of channels and flow turning, etc. By applying the classical hydraulic coefficients which can be found in the literature according to the flow conditions, hydraulic characteristics in regenerative cooling passages can be obtained effectively through dividing the pressure loss into friction loss and local resistance loss. Satisfactory agreement has been obtained by comparing the present results with experimental measurement of water flow test. In addition, the present results were in good agreement with CFD results when the actual coolant, kerosene was used. Therefore, the application of the present method is expected to be useful to design regeneratively cooled combustors.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.1-9
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• 2012

Applicability of regenerative cooling in 2,500 N-class bipropellant thruster using hydrogen peroxide and kerosene was considered for improvement of performance and application in various missions. Calculation was performed by one dimensional approach using hydrogen peroxide as a coolant. The heat flux of thruster at nozzle throat was estimated at 18 - 20 MW/$m^2$. Designed cooling channel width and height were 2.5 mm and 0.5 mm, respectively. Based on designed cooling channel configuration, flat plate model was manufactured and tested for estimation of pressure drop in cooling channel, and CFD analysis was compared with the test result. The maximum error between CFD analysis and experimental result was approximately 13% and average error was approximately 5%.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.16-17
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• 2002

재생냉각은 엔진 경량화 및 높은 추력을 발생시킬 수 있으며 엔진이 장시간 작동할 경우에도 추력의 변화가 일어나지 않는 우수성으로 인해, 액체로켓엔진에서 보편적으로 사용되고 있는 냉각방식이며, 고성능 액체로켓엔진 개발에 있어서 핵심기술이다. 일반적으로 재생냉각 방식은 연소기 내벽에 형성된 냉각유로에 연료 또는 산화제를 흘려보내 고온고압의 연소실내에 온도 경계층을 생성시키면서 벽면온도를 적정온도 이내로 유지하는 것이 목적이며, 또한 냉각유로에서의 압력강하가 추진제 공급 시스템의 공급 압력의 한계값을 넘어서지 않도록 하며, 냉각후의 연료 또는 산화제의 열역학적 상태가 엔진 작동 조건에 적합하도록 제어하여야 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.163-170
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• 2011

Applicability of regenerative cooling in 2,500 N-class bipropellant thruster using hydrogen peroxide and kerosene was considered for improvement performance and application in various missions. Calculation was performed by one dimensional approach using hydrogen peroxide as a coolant. In designed regenerative cooling thruster, heat flux at nozzle throat was estimated at 18 ~ 20 $MW/m^2$. Designed cooling channel width and height were 2.5 mm and 0.5 mm, respectively. Based on designed cooling channel configuration, flat plate model was manufactured and tested for estimation of pressure drop in cooling channel, and CFD analysis was compared with the test result. The maximum error between CFD analysis and experimental result was approximately 13% and average error was approximately 5%.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.37-46
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• 2018

A design study on the cooling channel configuration in a regeneratively cooled supersonic combustor was performed. The flow parameters on the hot- and cold-side channels were calculated using a quasi-one-dimensional model. The heat transfer between these two sides was estimated as a part of the flow calculation. For the reference configuration, the total amount of heat exchanged was 10.7 kW, the heat flux was $566kW/m^2$, and the fuel temperature increase between the inlet and outlet was 153 K. Seven designs of the heat exchanger channel were compared for their heat transfer performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.7
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• pp.112-117
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• 2003

The brazing of copper alloys and duplex stainless steels is an indispensable manufacturing technology for thrust chambers with regenerative cooling. For setting up the optimized brazing conditions, C18200 copper alloy plate with machined cooling channels and S31803 stainless steel plate are brazed with AMS4764 filler metals of which thickness is 50${\mu}m$ and 80${\mu}m$ They are tested by X-ray radiography, strength/leakage and fracture tests, and fracture surface inspection. The results obtained by the suggested conditions are that the specimen brazed with filler metal thickness of 50${\mu}m$ has good strength properties and brazed zone. However, the specimen with filler metal thickness of 80${\mu}m$ has the brazed zone with cooling channel obstruction and enlargement.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.4
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• pp.67-72
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• 2004

A regenerative cooling system has been designed through empirical 1-D analysis for a liquid rocket engine of 30-ton-level thrust. The hot-gas-side wall temperature from 1-D analysis shows 100K difference compared to 3D CFD analysis. Two variations of design with same cooling performance are suggested for different maximum channel widths i.e., 4mm and 2mm. The coolant pressure drop of the latter design is higher by 20%. The maximum liner temperature is about 700K when TBC and the thermal resistance of carbon deposit are considered. So film cooling is recommended to increase the cooling capacity as the present cooling capacity is insufficient