A re-examination of the laser-supported combustion wave

Abstract

The basic equations and numerical solution procedures for a laser-supported "combustion" wave were reexamined with the objective of obtaining an unambiguous solution for the entire wave, including the region far downstream of the temperature peak. Correct boundary conditions far downstream of the wave were determined and a technique for numerical solution of the entire boundary value problem was developed. Solutions obtained for laser-supported combustion waves in hydrogen were compared with results of the shooting technique of Kemp and Root. The latter technique yields essentially the same relationship between incident laser intensity and mass flux through the wave as our complete solution. However, the Kemp-Root technique provides a solution for only part of the wave and is incapable, in general, of correctly predicting the fraction of incident laser intensity absorbed in the wave. The complete wave solution is also applicable to the propagation of lasersupported waves away from a fixed end wall at large times after the wave is initiated at the wall.