To construct a stability estimation tool for injection-coupled instability in rocket engines, a linear stability analysis was applied. The amplifying factor related to injector-element acoustics and the damping factor related to chamber acoustics were defined. A complex vector, which is a function of these factors, was introduced. The stability for gain and that for phase were defined by the vector, and the bulk stability was defined by these stabilities. Because of time-lag findings obtained from subscale firing tests, the instability index, which was defined as inverse of the bulk stability, was defined only by the stability of gain. To validate the tool, the stability of cryogenic oxygen/hydrogen firing tests with a full-scale chamber was rated. The average acceleration was applied as an instability index for the firing tests. By setting the instability index by the tool at 1×103 as the threshold that divides “unstable” and “stable,” the stability obtained by the tool and that of the firing test showed a good correlation for three test cases. In the fourth test case, the tool could not re-create the test result. In conclusion, the present tool can detect an instability that is dominated by gains rather than by time lags.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Stability Index for Injection-Coupled Instability in Full-Scale Firing Tests



    Published in:

    Publication date :

    2017




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English



    Classification :

    BKL:    55.50 Luftfahrzeugtechnik / 55.50
    Local classification TIB:    770/7040



    Stability Index for Injection-Coupled Instability in Full-Scale Firing Tests

    Kobayashi, Kan / Nunome, Yoshio / Tomita, Takeo et al. | AIAA | 2017


    Full-Scale Firing Tests of Variable Flow Ducted Rocket Engines Employing Gap Solid Fuel Gas Generator

    Nakayama, Hisahiro / Ikegami, Yoshiyuki / Yoshida, Akihiko et al. | AIAA | 2009


    Full-scale wing tests

    Engineering Index Backfile | 1946


    Full-scale pavement tests

    Organization for Economic Co-operation and Development / OECD, Scientific Expert Group on Traffic Safety of Children | SLUB | 1985


    Full-scale collision tests

    Carlebur, A. F. C. | British Library Conference Proceedings | 1993