👉 The grain fluid, also known as the grain size or particle size distribution, refers to the range of sizes of solid particles present in a fluid mixture, typically in the context of colloidal or suspensions. It describes how the particles are distributed along a continuum scale, often expressed as a mean particle size or a range of sizes. This concept is crucial in understanding the physical properties and behavior of complex fluids, as it influences factors such as viscosity, stability, and flow characteristics. For instance, a narrow grain size distribution might lead to more uniform flow properties, while a broad distribution can result in more heterogeneous behavior.
