The regenerative pump is a rotor-dynamic turbomachine capable of developing high heads at low flow rates and low specific speeds. In spite of their low efficiency, usually less than 50%, they have found a wide range of applications as compact single-stage pumps with other beneficial features. The potential of a modified regenerative pump design is presented for the consideration of the performance improvements. In this paper the fluid dynamic behavior of the novel design was predicted using a one-dimensional model developed by the authors. Unlike most one-dimensional models previously published for regenerative pumps, the momentum exchange is numerically computed. Previous one-dimensional models relied on experimental data and correction factors; the model presented in this paper demonstrates an accurate prediction of the pump performance characteristics without the need for correction with experimental data. The validity of this approach is highlighted by the comparison of computed and measured results for two different regenerative pump standards. The pump performance is numerically assessed without the need of correction factors or other experimental data. This paper presents an approach for regenerative pumps using a physically valid geometry model and by resolving the circulatory velocity in the peripheral direction.