Recent Experimental Efforts on High-Pressure Supercritical Injection for Liquid Rockets and Their Implications
Figure 23
Plot of the averaged dark-core length (a) and the root mean square (RMS) of the length variations (b) normalized by the inner diameter of a LN2/GN2 coaxial jets injector. The solid symbols and lines represent the data when the acoustic driver is off, and the hollow symbols and dotted lines show the data when the acoustic driver was operated at ~3 kHz. The diamond, square, and up-triangle symbols are sub-, near-, and supercritical chamber pressures, respectively. All cases are for the high nominal outer-jet temperature of ~190 K. In the inset, the words sub, near, and super refer to subcritical, near critical, and supercritical chamber pressures, respectively, and the words OFF and ON refer to the acoustic driver being off and on at ~3 kHz, respectively. Davis and Chehroudi [42, 43].
