PARAMETRIC STUDIES OF STRONG GASEOUS DETONATIONS

Abstract

An IBM 704 computer program used for a parametric study of gaseous detonations is described. In addition to being able to define the thermodynamic and gas dynamic properties of the equilibrium, one-dimensional process it is possible to investigate the energy released. On the basis that the net energy release of the detonation equals the changes of enthalpy and kinetic energy of the reactants as they change to reaction products, it is seen that exothermic reactions soon become overridden by endothermic processes as the strong detonation wave velocity increases. Thus, it becomes possible to define the limits of gaseous detonations by a composition (equivalence ratio)-velocity coordinate system for prescribed reactant temperature and pressure conditions. The lower velocity limit is the Chapman- Jouguet condition and the upper velocity limit is the zero energy release condition. Parametric studies of oxygenhydrogen and air-hydrogen detonations were conducted for a wide range of initial temperatures and pressures. Typical variations of equilibrium product gas composition and temperature with wave velocity are presented and discussed. For oxygen--hydrogen detonations it was observed that the Chapman-Jouguet condition for the stoichiometric mixture produces the maximum more » energy release. The limits of detonations were broadened by higher reactant pressures and narrowed and shifted to lower velocities by higher reactant temperatures. Air - hydrogen detonations, however, showed larger energy release for leaner than stoichiometric mixtures, reaching a maximum at approximately an equivalence ratio of 4. However, the limits of air-hydrogen detonations displayed similar characteristics to the oxygen--hydrogen process. (auth) « less