slowflowing

Slowflowing is an informal term used to describe materials or fluids that exhibit very slow flow under applied stresses, typically because of high viscosity, a high yield stress, or complex time-dependent rheology. In rheology, it is often used to describe fluids whose viscosity remains high at low shear rates, contrasting with Newtonian fluids that flow more readily under small stresses.

Measurement and behavior: The flow behavior of slowflowing materials is usually characterized by viscosity versus shear rate. Such materials may be non-Newtonian, showing shear-thinning, thixotropy, or viscoelastic relaxation. Experimental assessment uses rheometers to quantify apparent viscosity at a specified shear rate, or to determine yield stress for materials that only begin to flow above a threshold stress.

Causes and factors: Temperature is a primary driver; as temperature increases, many materials become less viscous. Composition, molecular weight, and the presence of crystals or polymers can greatly increase resistance to flow. Time-dependent phenomena such as aging or structure formation can make a fluid progressively slower.

Examples and domains: Common examples include syrups, honey, bituminous pitches, and certain glass-forming melts or highly viscous magmas. In geology, slowflowing lava domes and lava flows reflect high viscosity. In materials science, glasses and polymer melts near the glass transition can behave as slowflowing solids over short timescales.

Notes: Slowflowing is descriptive rather than a formal technical term, and its interpretation depends on the timescale and stress conditions. It is often used in discussions of process feasibility, handling, and storage of viscous materials.