Turbulent flows laden with solid particles or liquid droplets are a common occurrence in both nature and technology. This book provides the characteristics of three kinds of particle-laden, steady, axi-symmetric, near field, free jet turbulent flows. The dispersed phases constitute small water particles with low concentration, small oil particles with relatively high concentration, and large solid particles with low concentration.Size and velocity of continuous and dispersed phases are measured by using Phase Doppler Particle Analyzer, PDPA. Two general empirical equations are derived for the two regions (potential core and intermediate transition) capable of predicting the mean velocity of the particles. In many engineering fields such as chemical, mechanical and environmental, fluid injection techniques have been widely utilized for promoting chemical reactions, waste treatment, gas mixing, heat and mass transfer. They are also used in combustion and drying applications, for cooling purposes and to control dangerous gas clouds. Pulverized-coal combustors, cyclone separator classifiers, and even rocket motors are also important examples of particle-laden turbulent free jets.