Laser speckle correlation technique application for study of aluminum nanopowder combustion.

Abstract

This paper presents the results of application of the laser speckle correlation (LSC) technique for studying the combustion process of aluminum-based nanopowders. For assessing the results, a combined experimental scheme is proposed with simultaneous application of LSC analyses and another feasible method of nanopowder combustion study, i.e., laser monitoring. In this paper, we present the principle of using the LSC technique to characterize the surface changes of nanopowder during combustion. Calculating the correlation coefficient of image sequencing, it is possible to estimate the time parameters of combustion of aluminum nanopowder and an aluminum mixture with iron nanopowder. Comparing the results obtained with the LSC method and laser monitoring, we conclude that LSC is quite acceptable for investigating the combustion process of metal nanopowders. In contrast with laser monitoring, the LSC method allows us to determine the preheating period preceding the first combustion wave. In practice, the LSC method application for nanopowder combustion control is prospective because of the simple hardware implementation.