A granular vibration pumping system employing a vertically oscillating pipe offers a promising approach for particulate transport. When a pipe is inserted into a granular bed and vibrated, powder materials can climb in the pipe owing to the so-called granular capillary action. While most of the prior studies have focused on the effects of vibration parameters and pipe geometry, the influence of powder bed pressure remains unclear. This study experimentally and numerically examines the impact of externally applied pressure on particle climbing behavior. The results show that the applied pressure markedly increases the particle climbing height by promoting the inflow beneath the pipe and enhancing interparticle forces. In some cases, particles become transportable under externally applied pressure. In addition, the climbing height increases with the vibration frequency under externally applied pressure, owing to greater acceleration. However, excessive pressure may cause jamming, which can limit the improvement of transport performance.
Suzuki et al. (Tue,) studied this question.