Impulsive Flows

This project is funded by ERC-Advanced Grant

My goal is to investigate impulsive flows that occur both in nature and technological applications, where fluid is accelerated due to sudden motion of an object or boundary, which leads to an additional instationary drag or lift forces. This project will shed new light on the understanding of the fundamental properties and flow physics of these impulsive flows. Theoretical concepts that are used today, do not go much beyond those laid down almost 100 years ago. With today’s level of technology and experimental tools I will be able to break new ground in the understanding of these flow phenomena that are very challenging both experimentally and numerically. First, a novel-concept flow facility will be built, based on a high performance robotic arm; this robot arm can move and rotate various objects in a water-filled tank along prescribed trajectories with known acceleration and rotation. The fluid motion is measured using tomographic particle image velocimetry (PIV), of which the measurement volume can move along with the objects using auxiliary robot arms. New PIV approaches will be developed that measure fluid acceleration varied within the short times of these impulsive motions. Then a systematic investigation is performed on various impulsive flows where the rate of acceleration and rotation rate can be varied, in order to find new and improved relationships between the measured hydrodynamic force histories and relevant flow quantities, such as velocity, acceleration, and rotation rate, and the time scales at which these phenomena occur. These will represent real-life impulsive flows. Experimental approaches and results will be used to validate numerical methods. The results of this investigation will fill gaps in our knowledge of impulsive flows, and give more accurate estimates of hydrodynamic forces. This will improve the prediction of structural loads and reduce failure and discomfort, with impact on aeronautics, wind energy, maritime and offshore technology.

Chair:
Fluid Mechanics

People involved:
prof. dr. ir. J. Westerweel
ir. J. Reijtenbagh
ir. N. Savelli
ir. L. van Dalen
ing. E. Overmars
ing. G. J. Mulder