Scaling laws based on the concept of dimensional similitude are proposed to simulate the hydrodynamics of hot and Iarge particle systems at conditions of cold and small particle systems.This technique uses the concept of dimensional similitude to accomplish this by maintaining certain dimensional groups constant in the large,hot and small,cold systems.However.there are certain limitations with this technique.One of them is that the particle size in the small.cold system is usually smaller than in the large.hot system.Because particle size iS such a dominant parameter in fluidized systems.this can certainly affect the simulation.An alternative method of simulating hot hydrodynamics in ambient-temperature Group A particle systems has been proposed.In this method,the same calculated drag force is maintained between the two systems.The drag force is varied by changing the gas density of the cold system so that it matches the drag force in the hot system.