Qualitative Analysis of Spray Characteristics of Impinging Jets Using a Gelled Non-Newtonian Propellant Simulant

Abstract

The utilization of liquid and solid fuels for propulsion and combustion processes with Newtonian characteristics are widely known. However, recent studies are considering the application of shear-thinning non-Newtonian fuels as alternative simulant since they have some advantages compared to the conventional propellants although there are challenges of providing better spray performance during the corresponding process. This paper, therefore, presents the results of the experimental investigations of the “near-field” spray characteristics with utilizing imaging techniques which evaluates the sheet formation and breakup length of four different spray patterns produced by the jet impingement of a gelled non-Newtonian propellant simulant. The qualitative analysis of this study shows that the spray patterns are different compared to those that are shaped by using Newtonian liquid fuels. This could lead to supposition that the non-Newtonian rheology of the gelled propellant simulant postponed the sheet and ligaments breakup, including the mode change of the atomization. In addition, the atomization of the sheet at different flow parameters could occur due to the formation and the sheet wave instability when aerodynamic and hydrodynamic of their origin are closely considered. This was further supported by the occurrence of perforations in the sheet.