A direct method of calculating bottom orbital velocity under waves

This report describes work carried out into the movement of sand by combining waves and currents.

A method is presented for calculating the bottom orbital velocity under a wave simply and directly for its known height and period, and the water depth. When suitably nondimensionalised the results all fall on a sinle curve, with separate curves for monochromatic and random (JONSWAP spectrum) waves. The r.m.s velocity under random waves may be smaller or larger then on the water-depth.