Lei de Stokes (arrasto esfera)

This calculator applies Stokes' Law to determine the viscous drag force on a sphere moving through a fluid. The formula F = 6πμrv relates the drag force (F) to the fluid's dynamic viscosity (μ), the sphere's radius (r), and its velocity (v). The calculation is valid only for laminar flow, where the Reynolds number is low (Re < 0.1).

Usage is straightforward: enter the fluid viscosity, sphere radius, and velocity. The calculator multiplies these values by 6π to obtain the drag force. Consistent units are essential, such as Pa·s for viscosity, meters for radius, and m/s for velocity, yielding Newtons. The result represents the fluid resistance opposing the sphere's motion.

This tool is useful in areas like particle sedimentation in liquids, centrifugal separation, studies of microparticles in suspension, and projects involving slow movement of spherical bodies in viscous fluids. For example, environmental engineers use it to estimate settling velocities of pollutants in water bodies, and pharmaceutical scientists to calculate particle sedimentation in medications.

Important caveats: Stokes' Law applies only to rigid spheres, laminar flow, and incompressible fluids. Non-spherical particles or rough surfaces can cause significant deviations. The formula also ignores wall effects (if the sphere is near a surface) and particle interactions. Always check the Reynolds number to ensure validity.