Related Experiment Video
Updated: May 22, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Temperature-pressure scaling for air-fluidized grains near jamming
L J Daniels1, T K Haxton, N Xu
1Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396, USA.
Abstract:
We present experiments on a monolayer of air-fluidized beads in which a jamming transition is approached by increasing pressure, increasing packing fraction, and decreasing kinetic energy. This is accomplished, along with a noninvasive measurement of pressure, by tilting the system and examining behavior versus depth. We construct an equation of state and analyze relaxation time versus effective temperature. By making time and effective temperature dimensionless using factors of pressure, bead size, and bead mass, we obtain a good collapse of the data but to a functional form that differs from that of thermal hard-sphere systems. The relaxation time appears to diverge only as the effective temperature to pressure ratio goes to zero.
Related Concept Videos
Pressure of Fluids
Fluid Pressure over Flat Plate of Constant Width
The resultant force...
Fluid Pressure over Flat Plate of Variable Width
The pressure distribution on the plate can be calculated by determining the force that acts on a differential area strip of the plate. Thus, the magnitude of the force is equal to the...
Pressure Variation in a Fluid at Rest
When measuring pressure at two different levels within the fluid, the difference in pressure...
Fluid Pressure over Curved Plate of Constant Width
Vapor Pressure of Fluid
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...

