81 citations · 795 across the 30 of their papers we have counts for
30 papers
Coevolving aerodynamic and impact ripples on Earth
Hezi Yizhaq, Katharina Tholen, Lior Saban +11
Windblown sand creates multiscale bedforms on Earth, Mars, and other planetary bodies. According to conventional wisdom, decameter-scale dunes and decimeter-scale ripples emerge vi…
Unified Flow Rule of Undeveloped and Fully Developed Dense Granular Flows Down Rough Inclines
Yanbin Wu, Thomas Pähtz, Zixiao Guo +3
We report on chute measurements of the free-surface velocity in dense flows of spheres and diverse sands and spheres-sand mixtures down rough inclines. These and previous measu…
Effects of particle elongation on dense granular flows down a rough inclined plane
Jixiong Liu, Lu Jing, Thomas Pähtz +3
Granular materials in nature are nearly always non-spherical, but particle shape effects in granular flow remain largely elusive. This study uses discrete element method simulation…
Dispersive wave propagation in disordered flexible fibers enhances stress attenuation
Peng Wang, Thomas Pähtz, Kun Luo +1
We experimentally and computationally analyze impact-shock-induced stress wave propagation in packings of disordered flexible fibers. We find that dispersive wave propagation, asso…
The role of coherent airflow structures on the incipient aeolian entrainment of coarse particles
Xiao-Hu Zhao, Manousos Valyrakis, Thomas Pähtz +1
The role of coherent airflow structures capable of setting gravel-size particles in motion is studied theoretically and experimentally. Specifically, a micromechanical model based…
Addressing bedload flux variability due to grain shape effects and experimental channel geometry
Thomas Pähtz, Yulan Chen, Jiafeng Xie +8
The study-to-study variability of bedload flux measurements in turbulent sediment transport borders an order of magnitude, even for idealized laboratory conditions. This uncertaint…
Influence of slope angle on deposit morphology and propagation of laboratory landslides
Yan-Bin Wu, Zhao Duan, Jian-Bing Peng +2
Landslide deposits often exhibit surface features, such as transverse ridges and X-shaped conjugate troughs, whose physical formation origins are not well understood. To study the…
Shear thinning of non-Brownian suspensions and its variation at different ambient conditions
Yuan Lin, Peiwen Lin, Ying Wang +4
Immiscible contaminants are commonly involved in naturally occurring suspensions. The resulting variations of their flow behavior has rarely been evaluated. Here, we investigate th…
Anomalous Scaling of Aeolian Sand Transport Reveals Coupling to Bed Rheology
Katharina Tholen, Thomas Pähtz, Sandesh Kamath +2
Predicting transport rates of windblown sand is a central problem in aeolian research, with implications for climate, environmental, and planetary sciences. Though studied since th…
Turbidity currents propagating down an inclined slope: particle auto-suspension
Jiafeng Xie, Peng Hu, Chenlin Zhu +2
The Turbidity current (TC), a ubiquitous fluid-particle coupled phenomenon in the natural environment and engineering, can transport over long distances on an inclined terrain due…
Copebot: Underwater soft robot with copepod-like locomotion
Zhiguo He, Yang Yang, Pengcheng Jiao +3
It has been a great challenge to develop robots that are able to perform complex movement patterns with high speed and, simultaneously, high accuracy. Copepods are animals found in…
Megaripple mechanics: bimodal transport ingrained in bimodal sands
Katharina Tholen, Thomas Pähtz, Hezi Yizhaq +2
Aeolian sand transport is a major process shaping landscapes on Earth and on diverse celestial bodies. Conditions favoring bimodal sand transport, with fine-grain saltation driving…
Fluid-particle interaction regimes during the evolution of turbidity currents from a coupled LES/DEM model
Jiafeng Xie, Peng Hu, Thomas Pähtz +2
In this paper, fluid-particle interactions in lock-exchange turbidity currents (TCs) over a flat bed are investigated using a model combining LES and DEM (Large-Eddy Simulation and…
Scaling laws for planetary sediment transport from DEM-RANS numerical simulations
Thomas Pähtz, Orencio Duŕan
We use an established discrete element method (DEM) Reynolds-averaged Navier--Stokes (RANS)-based numerical model to simulate non-suspended sediment transport across conditions enc…
Single-dopant band bending fluctuations in MoSe measured with electrostatic force microscopy
Megan Cowie, Rikke Plougmann, Zeno Schumacher +1
In this work, we experimentally demonstrate two-state fluctuations in a metal-insulator-semiconductor (MIS) device formed out of a metallic atomic force microscopy tip, vacuum gap,…
Unified model of sediment transport threshold and rate across weak and intense subaqueous bedload, windblown sand, and windblown snow
Thomas Pähtz, Yonghui Liu, Yuezhang Xia +3
Nonsuspended sediment transport (NST) refers to the sediment transport regime in which the flow turbulence is unable to support the weight of transported grains. It occurs in fluvi…
Unification of Aeolian and Fluvial Sediment Transport Rate from Granular Physics
Thomas Pähtz, Orencio Durán
One of the physically least understood characteristics of geophysical transport of sediments along sediment surfaces is the well known experimental observation that the sediment tr…
The effect of turbulence on drifting snow sublimation
Zhengshi Wang, Ning Huang, Thomas Pähtz
Sublimation of drifting snow, which is significant for the balances of mass and energy of the polar ice sheet, is a complex physical process with intercoupling between ice crystals…
Universal friction law at granular solid-gas transition explains scaling of sediment transport load with excess fluid shear stress
Thomas Pähtz, Orencio Durán
A key interest in geomorphology is to predict how the shear stress exerted by a turbulent flow of air or liquid onto an erodible sediment bed affects the transport load $M\tild…
Limitations of empirical sediment transport formulas for shallow water and their consequences for swash zone modelling
Wei Li, Peng Hu, Thomas Pähtz +2
Volumetric sediment concentrations computed by phase-resolving swash morphodynamic models are shown to exceed unity minus porosity (i.e. the maximal physically possible concentrati…
Fluid forces or impacts: What governs the entrainment of soil particles in sediment transport mediated by a Newtonian fluid?
Thomas Pähtz, Orencio Durán
In steady sediment transport, sediment deposition is balanced by entrainment of bed particles by fluid forces or particle-bed impacts. Here we propose a proxy to determine the role…
The Cessation Threshold of Nonsuspended Sediment Transport Across Aeolian and Fluvial Environments
Thomas Pähtz, Orencio Durán
Using particle-scale simulations of non-suspended sediment transport for a large range of Newtonian fluids driving transport, including air and water, we determine the bulk transpo…
An optimized dispersion-relation-preserving combined compact difference scheme to solve advection equations
Ching-Hao Yu, Dan Wang, Zhiguo He +1
In this study, we first present an improved version of the classical sixth-order combined compact difference (CCD6) scheme to enhance the convective stability of advection equation…
Is it appropriate to model turbidity currents with the three-equation model?
Peng Hu, Thomas Pähtz, Zhiguo He
The three-equation model (TEM) was developed in the 1980s to model turbidity currents (TCs) and has been widely used ever since. However, its physical justification was questioned…