Method and system for measuring the kinematic viscosity of a free fluid stream

A computer implemented method, wherein said method takes as input a first image of an area of interest of a fluid stream, a section, s0, of said opening and an output volume flow rate, U0, of the fluid stream from said opening, a second time-shifted image of at least two features of the fluid stream, wherein said features are present in the first image provided as input,

• wherein said method provides as output a kinematic viscosity, η, of the fluid;
• wherein said method comprises the following steps:
• digital processing of the first and second images to measure a displacement of said features;
• computing velocities of each said features from a measure of the displacement over a time shift between the first and second images, and
• computing the kinematic viscosity of the fluid with a mathematical or physical model from the velocities, the section, s0, and the output volume flow rate, U0.

A process for measuring a kinematic viscosity, η, of a fluid stream flowing from an opening with constant acceleration,

• wherein said process comprises the following steps:
• (a) acquiring, with an image recording device, at least one image of an area of interest of a fluid stream;
• (b) modelling, with a data processing device, a geometrical profile of the fluid stream trough a digital processing operation of the acquired image;
• (c) computing, with a data processing device, the kinematic viscosity, η, of the fluid with a mathematical or physical model from the modelled geometrical profile, the section, s0, of the opening and the output volume flow rate, U0, of the fluid stream.