• Title/Summary/Keyword: Stability Rating Test

Search Result 44, Processing Time 0.033 seconds

Combustion Stability Rating Test of Liquid Rocket Engine Thrust Chamber (액체로켓엔진 연소기 연소안정성 평가시험)

  • Ahn, Kyubok;Kim, Jong-Gyu;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.18 no.2
    • /
    • pp.60-66
    • /
    • 2014
  • As a evaluation method of combustion stability in a liquid rocket engine thrust chamber, external disturbance devices are used. In the paper, the study on pulse-gun ignition tests for a combustion stability rating test of a thrust chamber was performed. Charging volume of pulse-guns was determined by confirming the intensities of the pressure waves from the ignition tests in the cold-flow conditions. While using same injector head, combustion instabilities were not encountered during 14 hot-firing tests without pulse-guns but combustion instabilities were triggered by pulse-gun ignition during 2 hot-firing tests. The results showed that the pulse-gun ignition test could be the evaluation method and could reduce the hot-firing test number for the stability rating of a thrust chamber.

A Experimental Study on Combustion-Stability Rating in a Subscale Chamber (모형 연소실에서 분사기 연소 안정성 평가에 관한 실험적 연구)

  • Kim, Chuljin;Sohn, Chae Hoon
    • 한국연소학회:학술대회논문집
    • /
    • 2012.04a
    • /
    • pp.77-78
    • /
    • 2012
  • To predict combustion instability in actual full-scale combustion chamber of rocket engines, air-injection test is proposed with scaling techniques. From the data, damping factors have been obtained as a function of hydraulic parameter and the data give us instability map. Two instability regions are presented and it is found that they coincide reasonably with them from hot-fire test with full-scale flow rates. Accordingly, the proposed approach can be applied cost-effectively to stability rating of jet injectors when mixing of fuel and oxidizer jets is the dominant process in instability triggering.

  • PDF

Combustion Stability Rating Test under Low Pressure Condition of a 75-$ton_f$ LRE Thrust Chamber (75톤급 액체로켓엔진 연소기의 저압 조건에서 수행된 연소안정성 시험)

  • Lee, Kwang-Jin;Kang, Dong-Hyuk;Lim, Mun-Ki;Ahn, Kyu-Bok;Han, Yeoung-Min;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.05a
    • /
    • pp.231-238
    • /
    • 2010
  • Combustion stability rating tests under condition low pressure of a 75-$ton_f$ liquid rocket engine(LRE) thrust chamber were carried out. Mixing head with decreased number of injectors than that of the other but with the same mass flow rate to the combustion chamber showed self-oscillation instability in chamber pressure of 30 bar. The other combustion chamber with increased number of injectors showed that high frequency combustion stability was maintained under condition of same pressure, but self-oscillation instability was generated in chamber pressure of 20 bar which can be considered as stability boundary region of this mixing head.

  • PDF

Study on the stability of tunnel and rock mass classification in Danyang limestone quarry (단양 석회석 광산터널의 암반 평가 및 안정성 연구)

  • ;Choon Sunwoo;Kong Chang Han;yeon-jun Park
    • Tunnel and Underground Space
    • /
    • v.6 no.2
    • /
    • pp.131-143
    • /
    • 1996
  • In-situ survey and laboratory rock test were carried out for rating rock mass around the tunnel that some failures had been occurred in Danyang limestone quarry. For rating rock mass, several methods such as RMR, Q-system, rock strength etc. were applied. The stability analysis on tunnel was evaluated by numerical method FLAC. And The block theory using streographic projection was also applied for stability analysis. The 3-4 major discontinuity sets are distributed in rock mass around tunnel.

  • PDF

Stability Rating of Liquid Propellant Rocket Engine (액체 로켓엔진의 연소 안정성 평가)

  • 손채훈;김영목
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2003.10a
    • /
    • pp.73-77
    • /
    • 2003
  • Stability rating of KSR-III rocket engine is conducted based on stability rating tests in the course of development of KSR-III rocket engine. Rocket engine is approved to have combustion stabilization ability when it can suppress the external perturbation or pressure oscillation with finite amplitude and recover the original stable combustion. Rocket engine in flight nay be perturbed with unexpectedly large amplitude and thus a designer should not only assure combustion stabilization ability of the engine but also quantify the stabilization capacity. For this, several quantitative parameters and their evaluation are introduced. To verify dynamic stability of KSR-III rocket engine, five stability rating tests have been conducted. Based on these test results, such parameters are quantified and thereby, the stabilization capacity of KSR-III rocket engine is evaluated.

  • PDF

Experiments on Development A Pulse-Gun Pressure-Wave Inducing Device for Stability Rating Test Technique (연소안정성 평가시험 기법을 위한 펄스건 압력파 유도장치 개발 실험)

  • Lee, Kwang-Jin;Kim, Hong-Jip;Seo, Seong-Hyeon;Moon, Il-Yoon;Kim, Hyung-Mo;Lee, Soo-Yong;Ko, Young-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.3
    • /
    • pp.99-106
    • /
    • 2005
  • The SRT(stability rating test) technique, which is indispensable for the development of a LRE(liquid rocket engine), essentially requires a development of a combustion test sequence as well as artificial perturbation devices. For the development of an indigenous SRT technique, several combustion tests of sub-scale LRE were performed to search a proper combustion test sequence. At first, a pressure-wave inducing device which is used for adapting pulse gun was designed and a cooling gas supply system for the pressure-wave inducing device was set up to prevent a malfunction of pulse gun. Through the several combustion tests which included cooling procedure of a pressure-wave inducing device, a proper combustion test sequence was found out. It did not make any significant disturbance at normal combustion process. Finally, an indigenous SRT technique has been developed successfully.

Stability Rating of KSR-III Rocket Engine (KSR-III 로켓엔진의 연소 안정성 평가)

  • Sohn, Chae-Hoon;Kim, Young-Mog
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.32 no.3
    • /
    • pp.95-101
    • /
    • 2004
  • Stability rating of KSR-III rocket engine is conducted based on stability rating tests in the course of development of KSR-III rocket engine. Rocket engine is approved to have combustion stabilization ability when it can suppress the external perturbation or pressure oscillation with finite amplitude and recover the original stable combustion. Rocket engine in flight may be perturbed by unexpectedly large-amplitude pressure oscillation and thus a designer should not only assure combustion stabilization ability of the engine but also quantify the stabilization capacity. For this, principal quantitative parameters and their evaluation are introduced. To verify dynamic stability of KSR-III rocket engine, six stability rating tests have been conducted. Based on these test results, such parameters are quantified and thereby, the stabilization capacity of KSR-III rocket engine is evaluated.

Development and Design of Pulse Gun for Combustion Stability Rating Test (연소 안정성 평가 시험을 위한 펄스건 설계 및 개발 시험)

  • Go,Yeong-Seong;Lee,Gwang-Jin;Lee,Su-Yong;Lee,Dae-Seong
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.31 no.9
    • /
    • pp.103-109
    • /
    • 2003
  • The development of a pulse gun used for the combustion stability rating test(SRT) has been domestically tried out since the SRT should be accompanied in the process of the development of LREs. At the beginning of the development, a rupture problem of the pulse gun body had been solved by changing its material and increasing its thickness. Also, the sealing test was undertaken for a pulse gun equipped with a membrane before conducting a explosion test and by using a specially designed jig after a explosion test. Since it is appropriate to reuse the holder of a pulse gun cavity for an actual SRT, a series of experiments for several variants has been taken to make it reusable. After all, the solution for a reusable holder of a pulse gun has been found and applied for complementing its specification.

Application of Combustion Stabilization Devices to Liquid Rocket Engine (액체 로켓엔진에서 연소 안정화기구의 적용에 관한 연구)

  • Sohn Chae-Hoon;Moon Yoon-Wan;Ryu Chul-Sung;Kim Young-Mog
    • Proceedings of the KSME Conference
    • /
    • 2002.08a
    • /
    • pp.259-262
    • /
    • 2002
  • Application of combustion stabilization devices such as baffle and acoustic cavity to liquid propellant rocket engine is investigated to suppress high-frequency combustion instability, i.e., acoustic instability. First, these damping devices are designed based on linear damping theory. As a principal design parameter, damping factor is considered and calculated numerically in the chambers with various specifications of these devices. Next, the unbaffled chambers with/without acoustic cavities are tested experimentally for several operating conditions. The unbaffled chamber shows the specific stability characteristics depending on the operating condition and has small dynamic stability margin. The most hazardous frequency is clearly identified through Fast Fourier Transform. As a result, the acoustic cavity with the present design has little stabilization effect in this specific chamber. Finally, stability rating tests are conducted with the baffled chamber, where evident combustion stabilization is observed, which indicates sufficient damping effect. Thrust loss caused by baffle installation is about $2{\%}$.

  • PDF

Combustion Stability Rating Test under Low Pressure Condition of a 75-tonf-class LRE Thrust Chamber (75톤급 액체로켓엔진 연소기의 저압 조건에서 수행된 연소안정성 시험)

  • Lee, Kwang-Jin;Kang, Dong-Hyuk;Kim, Mun-Ki;Ahn, Kyu-Bok;Han, Yeoung-Min;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.14 no.5
    • /
    • pp.92-100
    • /
    • 2010
  • Combustion stability rating tests of 75-tonf-class thrust chamber for technology demonstration were carried out at a low pressure. Two kinds of mixing heads were used in this study. One of them has injectors of 631 and the other has injectors of 721. Mixing head with injectors of 631 showed a self-oscillation instability at the chamber pressure of 30 bar. Mixing head with injectors of 721 showed that a high frequency combustion stability was maintained under the same pressure and the same mass flow rate. But mixing head with injectors of 721 generated a self-oscillation instability at the chamber pressure of 20 bar and it was found that stability boundary region was changed due to the configuration of a mixing head from these results.