Various embodiments of the invention comprise devices, systems, and methods for estimating the rate at which rock, soil or any self-supporting material erode. Particular embodiments of the invention relate to devices and systems that subject a stationary soil or rock sample to shear stresses by rotating fluid about the soil or rock sample to simulate the effects of flowing fluids on the soil or rock sample. In various embodiments, the devices and systems include a torque cell unit and clutch assembly.