Particle image velocimetry system upgrade

点击翻译按钮获取中文摘要

Particle image velocimetry (PIV) is an experimental fluid dynamics research tool capable of measuring the velocity in a flow at several thousand points simultaneously.  This is achieved by seeding the flow with light-reflecting particles and illuminating a plane in the flow with pulsed light produced by a laser.  A digital camera acquires two images of this plane a very short time apart.  Proper processing of these images reveals the velocity of the fluid by measuring the distance travelled by the particles between the two pictures.  Detailed information about the velocity field, such as that provided by PIV, is the most powerful tool for interpreting flow behaviour and guiding intelligent design decisions for engineering equipment.The particular focus of this grant is to expand an existing PIV system to allow world-class measurements to be made.  To more completely characterise a flow, it is important to measure how the velocity changes from place to place in the flow.  This grant will add the necessary equipment to our existing PIV facilities to allow measurements to be made on two planes simultaneously.  Relationships between PIV measurements on two different planes will allow information to be extracted that will be the first of its kind in many applications.  Examples of investigations currently underway or being planned are: the transient motion of bubbles and particles near walls, two-phase flow in tubes, rough-wall turbulent boundary layer measurements, confined jets, and wall jets.  These flows have application in aerodynamics, power generation, environmental dispersion modelling, and many other industrial processes.