FLAME STABILIZATION MECHANISM OF A NEWLY DEVISED STRUT FOR THE SCRAMJET ENGINE

A newly devised strut for ramjet and scramjet engines was tested in su personic airflow to investigate its flame-holding characteristics. A c onventional strut with steps was divided into two parts at the steps a nd the intervening space between these two parts was changed to observ e the change of the flame-holding characteristics. To clarify the flam e stabilization mechanism, velocity fields, temperature and concentrat ion profiles in the interval between the resultant two struts were mea sured in the intervening space between the two parts by LDV, thermocou ples and gas chromatography. In the case of appropriate intervening sp ace, since the overall equivalence ratio was stoichiometric and so the temperature was high in spite of a short residence time, a flame coul d be established. If the intervening space was widened, however, the e quivalence ratio and the temperature decreased, and so the flame was b lown off, although the residence time became long.