Meaning
Multiphase transport models measure kinetic momentum exchange between immiscible phases against hydrodynamic drag coefficients and phase velocity differentials. During spray drying and flame pyrolysis of precursor solutions, liquid droplets travel through high-temperature gas streams while evaporating and reacting. Quantifying interfacial drag kinetics determines the acceleration, velocity slip, residence time, and trajectory of precursor droplets moving inside thermal reactors.
Multiphase Navier-Stokes equations incorporate drag kinetic expressions to map velocity slip between gas and liquid phases. Thermal reactor engineers utilize interfacial drag kinetics data to size reaction zones, optimize carrier gas flow rates, adjust burner tilt, and ensure complete calcination of aerosol particles before collection.
Momentum Exchange
Gas velocity fields surrounding suspended liquid precursor droplets exert shear forces across the liquid-gas interface. High interfacial drag kinetics accelerate momentum equilibration between carrier gas and droplets, shortening the distance required for droplets to reach stream velocity. Droplet deformation alters the effective drag coefficient dynamically during high-speed transit.
Thermal Residence
Time spent by reacting droplets within specific thermal windows determines precursor decomposition completeness and final powder crystallinity. Slower momentum transfer caused by lower interfacial drag kinetics extends droplet residence time in the high-temperature zone. Extended residence allows full evaporation of solvent species, preventing wet wall impacts and agglomeration in collection cyclones.
Particle Trajectory
Recirculation zones and turbulent eddies in aerosol reactors divert droplet pathways toward reactor surfaces when drag forces dominate inertial motion.
