✦ LIBER ✦

Relationship between aerodynamic entrainment threshold and hydrodynamic settling velocity of particles

✍ Scribed by J.P. le Roux

Publisher: Elsevier Science
Year: 1997
Tongue: English
Weight: 419 KB
Volume: 109
Category: Article
ISSN: 0037-0738
DOI: 10.1016/s0037-0738(96)00038-3

No coin nor oath required. For personal study only.

✦ Synopsis

Data on the critical shear stress (rc) at incipient grain motion under air flow have been carefully selected from the literature. It is shown that the non-dimensional Shields entrainment threshold (tic) in air is an exponential function of the dimensionless settling velocity (Wds) in water, of a sphere with a diameter equal to the sieve size. As Was can be related to the measured dimensionless settling velocity (Wdm) of natural grains, Wdm can be used directly to calculate/~c. For quartz grains in air, the equations are valid for sizes between 0.01 and at least 0.166 cm, i.e. silt to very coarse sand. The method is applicable to well sorted grains with a relatively high sphericity entrained on fiat surfaces.

📜 SIMILAR VOLUMES

Settling velocities and entrainment thre

Settling velocities and entrainment thresholds of biogenic sands (shell fragments) under unidirectional flow

✍ D. Paphitis; M. B. Collins; L. A. Nash; S. Wallbridge 📂 Article 📅 2002 🏛 John Wiley and Sons 🌐 English ⚖ 571 KB

Settling velocities and entrainment thresholds of biogenic sedimentary particles, under unidirectional flow conditions, are derived on the basis of settling tower and laboratory flume experiments. Material consisting predominantly of equant blocks (shell fragments of __Cerastoderma edule__, density,

Hydrodynamic Interactions and Mean Settl

Hydrodynamic Interactions and Mean Settling Velocity of Porous Particles in a Dilute Suspension

✍ Shing Bor Chen; Aiping Cai 📂 Article 📅 1999 🏛 Elsevier Science 🌐 English ⚖ 159 KB

A theoretical investigation is conducted to study hydrodynamic interactions among porous spheres under creeping flow conditions. The particles may differ in size and permeability. Based on the Brinkman equation governing the fluid flow inside the particle, the flow field, and the drag force and torq

Entrainment threshold of natural grains

Entrainment threshold of natural grains in liquids determined empirically from dimensionless settling velocities and other measures of grain size

✍ J.P Le Roux 📂 Article 📅 1998 🏛 Elsevier Science 🌐 English ⚖ 113 KB

Grain size plays a crucial role in sediment transport, but different methods of size analysis do not yield comparable results. Particle diameters obtained by settling tube, for example, cannot be employed in equations based on sieve sizes. Although the majority of experiments on the initiation of se