The influence of image analysis methodology on the calculation of granular temperature for granular flows

The granular temperature is an index of the level collisional activity in a flow, and increasingly important verification extended kinetic theories. related to square difference between particle’s velocity that group mean. Image analysis high-speed video most common method measure experimental flows depends on correlation search mask or portion original image next frame determine movement. This invariably involves some estimation location at resolution finer than pixels make up image. However, errors determining particle movement subpixel can be shown have significant impact identification. We show taking chain displacement vectors provides context apparent impulses particle. Here we propose two novel methods for flows, namely initializing Particle Velocimetry (PIV) systems where each subset centred previously determined reduce bias, filtering frequency basis. term these Guided-PIV Impulse Frequency Filtering (IFF), respectively. In exercise using synthetically generated images, produce substantially more accurate results ordinary applications PIV. IFF greatly influence analyzed framerate results. Our demonstrate practical improvements identification from analysis, throughout range quality levels, anticipate will enable assessment towards theorized models collisional-frictional flows.