Development and testing of liquid simulants

A group of liquid simulants was developed in order to ease the process of cold-flow testing by lowering associated costs and hazards while providing accurate analysis of desired liquid behavior through an injector. Simulants were made with the intention of modeling certain physical properties of the liquid such as density, viscosity, and surface tension. These simulant solutions are capable of modeling liquid propellants throughout large physical property ranges by simply modifying the ingredient ratios. The effectiveness of these solutions in simulating their intended liquids was measured by performing various density, viscosity, and surface tension experiments along with cold-flow tests comparing the liquid breakup and pressure drops across the injector as a function of Reynolds number, Weber number, Ohnesorge number, and mass flow rate. The experimental tests proved that the simulants tested accurately demonstrated desired liquid density, viscosity, and surface tension values and were more effective at modeling jet breakup and pressure drop behavior of specific propellants than that of traditional cold-flow experiments using de-ionized liquid water, with little-to-no added maintenance or cleanup.