Maldistribution

Maldistribution refers to the nonuniform distribution of a resource, such as fluid, heat, or chemical species, across a set of parallel channels, pipes, or components within a system. It occurs when some paths receive more flow, energy, or material than others, leading to uneven performance and inefficiency. The term is used in engineering, process design, and energy systems to describe a common obstacle to achieving uniform operation.

Causes of maldistribution include geometric nonuniformity in headers, manifolds, or channel cross-sections; pressure or head differences between branches; changes in viscosity or phase due to temperature; partial blockages or fouling; and dynamic operating conditions. Manufacturing tolerances, installation errors, and incomplete mixing can also contribute. Maldistribution can occur in cooling and heating networks, chemical reactors with parallel channels, and solar collectors.

Consequences include reduced heat transfer or reaction efficiency, localized overheating or underutilization of channels, higher pressure drop, increased energy consumption, and uneven wear or corrosion. In critical systems, maldistribution can compromise performance, safety margins, and equipment life. Detection often relies on flow measurements, pressure profiling, thermography, or computational fluid dynamics simulations.

Mitigation strategies aim to improve uniformity by mechanical and control methods, such as balancing valves, flow restrictors, properly designed manifolds or headers, crossover passages, and regular cleaning to prevent fouling. In design stage, simulations and scale models help optimize channel geometry and head distribution to minimize maldistribution across operating conditions.