Rammler

Rammler is a German surname. Like many surnames, it is borne by individuals across German-speaking regions and in diaspora communities, and may appear in various scholarly, professional, and historical contexts.

In science and engineering, the Rosin–Rammler distribution is a widely used model for describing particle size distributions in powders and granular materials. It is named after Rosin and Rammler, who introduced the model to characterize how many particles fall below a given size. The distribution provides a compact way to summarize how finely a material has been milled or processed.

The cumulative distribution function of the Rosin–Rammler model is F(D) = 1 − exp[−(D/d)^n] for D ≥ 0, where D is particle size, d is a characteristic size, and n > 0 is a shape parameter that reflects the spread of sizes. The corresponding probability density is f(D) = (n/d) (D/d)^{n−1} exp[−(D/d)^n]. The model is flexible and can describe a range of distributions by adjusting n and d.

Applications of the Rosin–Rammler distribution span mining, mineral processing, ceramics, pharmaceuticals, and other industries that produce or classify powders. It is commonly used to fit measured particle-size data and to inform process design, quality control, and scale-up. Parameter estimation is typically performed by nonlinear regression or by Rosin–Rammler plotting, which linearizes the transform for easier fitting.