GEOL 3032 Lecture : 3032 Week3
Document Summary
Objective: describe how and when particles get entrained by flows in water (sediment transport), or are deposited (non cohesive) We want to be able to understand what types of flows carry what types of sediment to: predict sediment transport, and to determine what flows might have transported grains we find in ancient sediment deposits. Quadratic stress law for shear stress and shear velocity. F fluid density, m l-3 (greek letter rho) Molecular viscosity (also called dynamic viscosity, because it is only apparent in a moving fluid), force per unit area per velocity gradient, ml-1 t-1, ns m-2 (greek letter mu) Poises (cgs) v kinematic viscosity ( / f) (greek letter nu) Velocity distribution uz velocity distribution in flow with respect to elevation above the bed, l t-1. Shear stress is tangential force parallel to bed produced by fluid viscosity and velocity shear. Particles will move when the bed shear stress exceeds a critical value.
