Accession Number : ADA267260


Title :   Acoustic Waves in Baffled Liquid-Propellant Rocket Emgines


Descriptive Note : Final rept. 14 Mar 91-14 May 93,


Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING


Personal Author(s) : Yang, Vigor ; Yoon, M W ; Wicker, J M


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a267260.pdf


Report Date : May 1993


Pagination or Media Count : 146


Abstract : A linear and nonlinear acoustic wave analysis has been developed for baffled combustion chambers. Results suggest three important effects of baffles on transverse modes of combustion instability. First, transverse waves can be longitudinalized inside baffle compartments. This may decouple combustion response from oscillatory motions if the processes near the injector face are sensitive to transverse variations in pressure. Second, severe restriction of the transverse component of acoustic velocity fluctuations is observed in baffle compartments. This may be key in stabilizing systems with velocity-sensitive combustion. Third, the frequency of oscillation is decreased with the addition of baffles, in agreement with experiments. One potentially destabilizing effect of baffles is the observed pressure concentration at the injector face. Pressure sensitive processes in this region may enhance instability. Limit cycles were observed for both two- and three-dimensional baffled chambers. Their most remarkable characteristic is high frequency modulation of the limit cycle amplitude.... Combustion instability; Liquid rocket propulsion; Acoustic waves.


Descriptors :   *ACOUSTIC WAVES , *LIQUID PROPELLANT ROCKET ENGINES , VELOCITY , FREQUENCY MODULATION , COMPARTMENTS , REGIONS , THREE DIMENSIONAL , PRESSURE , ACOUSTICS , BAFFLES , ROCKET PROPULSION , INSTABILITY , ACOUSTIC VELOCITY , OSCILLATION , AMPLITUDE , INJECTORS , AGREEMENTS , TRANSVERSE WAVES , COMBUSTION CHAMBERS , DIFFERENTIAL EQUATIONS , RESPONSE , VARIATIONS , CYCLES , MOTION , HIGH FREQUENCY


Subject Categories : Acoustics
      Solid Propellant Rocket Engines


Distribution Statement : APPROVED FOR PUBLIC RELEASE