AbstractNew friction factor estimates are computed from the total momentum transfer applied to a rippled sediment bed. The total time‐dependent momentum flux is achieved by implementing the double‐averaged horizontal momentum equation on the nearbed flow field collected with PIV. Time‐independent friction factors are obtained by regressing the total momentum flux to the common quadratic stress law given by. The resulting friction factors compare favorably with available analysis techniques including energy dissipation, vertical turbulence intensity, and maximum shear stress, but can be 2‐6 times smaller than estimates determined with the model byMadsen (1994)and the formula ofSwart (1974)using the ripple roughness.
