Low Frequency Sloshing Analysis of Cylindrical Containers with Flat and Conical Baffles

This paper presents an analysis of low-frequency liquid vibrations in rigid partially filled containers with baffles. The liquid is supposed to be an ideal and incompressible one and its flow is irrotational. A compound shell of revolution is considered as the container model. For evaluating the velocity potential the system of singular boundary integral equations has been obtained. The single-domain and multi-domain reduced boundary element methods have been used for its numerical solution. The numerical simulation is performed to validate the proposed method and to estimate the sloshing frequencies and modes of fluid-filled cylindrical shells with baffles in the forms of circular plates and truncated cones. Both axisymmetric and non-axisymmetric modes of liquid vibrations in baffled and un-baffled tanks have been considered. The proposed method makes it possible to determine a suitable place with a proper height for installing baffles in tanks by using the numerical experiment.

The Donghulin Woman from western Beijing: 14C age and an associated compound shell necklace

A female skeleton, whose 14C age is about 8540 BP (c. 7500 cal BC), from the basal part of the Holocene loess at Fenpo Gully, west of the village of Donghulin, Mentougou district of Beijing, was associated with a shell necklace restored from 68 gastropod shells. This unprecedented find also contributes new environmental information.