Disruption of Volatile and Nonvolatile Droplets Under Locally Supersonic Conditions

摘要: The disruption of simulated fuel droplets in supersonic flow is examined experimentally a drawdown wind tunnel. are accelerated the flow, achieving velocities relative to surrounding air with Mach numbers as high 1.8 and Weber 300. Monodisperse 100m-diam fluid generated using droplet-on-demand generator upstream tunnel entrance. imaged by direct close-up singleandmultiple-exposure imaging. Three test liquidswere employed: 2-propanol tetraethylene glycol dimethyl ether nonvolatile fluids, more volatile 50=50 hexanol-pentane mixture. decreased static pressure stream had potential give rise superheating droplet fluid, some cases, became significantly lower than vapor liquid. Droplet lifetimes for hexanol/pentane mixture appear be shorter due vaporization consistent superheating, although little impact observed on velocity number. Droplet-disruption patterns these conditions can classified into four different regions considering changes number downstream distance accelerate. drag coefficients associatedwith under locally generally higher those expected solid spheres, largely cross-sectional area change associated deformation/ breakup.