Assessment of a peristaltic device for drag reduction in pipes

The objective of this thesis, conducted within the Aerodynamics Laboratory of the Departamento di Scienze e Tecnologie Aerospaziale, DAST, (Department of Aerospace Science and Technology) of the Politecnico di Milano, is the practical experiment concerned with the implementation of actuators to facilitate a peristaltic motion of a deformable pipe in the attempt to reduce drag of fully developed turbulent flow. This thesis is a part of an ongoing study within DAST which looks to minimise drag in turbulent flow with the use of various types of wall motion. This thesis begins with a summary of the scientific principles that the desired drag reduction is based upon as well as a description of the previous wall motion drag reduction endeavours. Following this, details are given to the practical aspects of the experiments and finally, results and conclusions are drawn from the experimental sessions. Ultimately, no drag reduction was recorded in this particular study. This however, does not dismiss the idea of peristaltic motion of a wall as a method of drag reduction within turbulent flows. Instead, it highlights the practical challenges that need to be overcome in order for peristaltic motion to be effective. These challenges primarily revolved around the actuators and suggest that these particular actuators are not the optimal solution for this experiment.