Open-bottom permeameters (OBP) are commonly used for estimating the hydraulic properties of sediment beds under water bodies and fluxes across the sediment-water interface. The specific shape factor for an OBP flow situation is necessary for data interpretation. It is determined by the ratio of the permeameter tube radius to the tube's penetration depth within the sediment. Previous permeameter designs favored small radii which allowed for deeper penetration and stability of the tube. The shape factor is provided here for large footprint OBPs that allows for shallow penetration and greater radius. Through a numerical and analytical modeling study of the OBP hydrodynamics, previous knowledge on the OBP shape factor is generalized to the entire range of radius-to-penetration ratios that might be practically applied. The results reveal the advantages of the large footprint design, including better sensitivity due to the ability to impose larger discharge over a shorter test duration.
- hydraulic conductivity
- large footprint
- numerical and analytical methods
- open-bottom permeameter (OBP)
- shape factor
ASJC Scopus subject areas
- Water Science and Technology