Spiral casings are a vital element in reaction turbines for hydraulic energy generation. This work analyses the behavior of many variables of spiral chambers in five families of models: Logarithmic, Fermat, Galileo, Archimedes, and Polynomial spirals. It also studies seven inlet diameters of the chamber. Each prototype was evaluated with standardized boundary conditions. Virtual models of chamber spirals were built from mathematical equations. The behavior of the fluid inside the models was evaluated using computational fluid dynamics. The simulations were performed in the module CFX of ANSYS®19.1, and a velocity profile of the dynamic behavior of the fluid inside each spiral chamber was obtained. Absolute, tangential and radial velocities of 50, 75 and 100 % of the flow area of the spiral chamber outlets were evaluated. Using a statistic study of velocity values at the outlet of the chamber calculated through CFD, the maximum average velocity and the minimum standard deviation were established. Additionally, optimal criteria for choosing the most appropriate chamber of each type were estimated. These models indicate that Archimedes spiral casings with inlet diameters of 100 and 150 mm present the best fluid-dynamic behavior