Year of Publication


Degree Name

Master of Science in Mechanical Engineering (MSME)

Document Type

Master's Thesis




Mechanical Engineering

First Advisor

Dr. Sean C.C. Bailey


A turbulent channel flow was used to study the scaling of the combined effects of roughness and flow injection on the mean flow and turbulence statistics of turbulent plane Poiseuille flow. It was found that the additional momentum injected through the rough surface acted primarily to enhance the roughness effects and, with respect to the mean flow, blowing produced similar mean flow effects as increasing the roughness height. This was not found to hold for the turbulence statistics, as a departure from Townsend’s hypothesis was seen. Instead, the resulting outer-scaled streamwise Reynolds stress for cases with roughness and blowing deviated significantly from the roughness only condition well throughout the inner and outer layers. Investigation into this phenomena indicated that suppression of the large-scale motions due to blowing may have been contributing to this deviation.