Measurements of length effects on the dynamics of rigid fibers in a turbulent channel flow

Nonspherical particles such as fibers are commonly dispersed by turbulent boundary layer flows encountered in industry as well as our daily living environment. Fiber length has an effect on the orientation, translation, and rotation of fibers. In this experimental study it was found that irrespective of fiber length, mean squared fiber tumbling rates strongly increased in the buffer layer, but remained constant in the log-layer and the wake region. A clear length effect was observed as longer fibers tumbled at higher rates than shorter ones.