How Do Sand Grains of Different Coarseness Affect the Instability of the Flow in An Hourglass

This paper presents a dynamic simulation model for the behavior of sand in an hourglass, focusing on the instability of the sand flow and the collapse phenomena that occur due to frictional interactions between individual sand grains.The study explores the complex dynamics governing the movement and distribution of sand particles within the confined space of an hourglass, addressing how factors such as particle size, friction, and the angle of inclination influence the overall flow rate and stability.Through the development of a simulation model, we provide insights into the conditions under which the sand fails to flow smoothly, leading to clumping or blockage.The findings have implications for both the physical understanding of granular materials and potential applications in fields such as material science, engineering, and the design of devices relying on controlled granular flow.