It’s great if you can understand the flow profile of your application or the way the flow of a fluid behaves in a pipeline (based on its velocity and viscosity) because it’s from this information you can decide which of the many different types of flow meters are best suited to your application.
Flow measurement is the quantification of bulk fluid movement.
Two areas that the flow profile is based on are:
It is important to know what you are measuring e.g. air, water, milk, oil, sewerage etc this is because due to their differing viscosities every gas or fluid will behave differently as they flow through a pipe.
The flow profile of a fluid will vary according to whether it is Newtonian or non-Newtonian.
Examples of Newtonian fluids include milk, water, sugar solutions and mineral oils.
Examples of non-Newtonian fluids include paints, cement slurry, shampoos, blood, toothpaste and yoghurt.
Newtonian fluids have a tendency to ‘stick’ to the pipe walls, which means the liquid moves more slowly at the sides of the pipe than in the middle.
Newtonian liquids have a directly proportional relationship between the pressure of the liquid flowing through and the resistance caused by the fluid sticking to the pipe walls.
The behaviour of non-Newtonian fluids is harder to predict, as there is no relationship between pressure and resistance – the behaviour varies either with time or as a consequence of changes in the shear force inflicted by resistance from the pipe wall
There are three types of flow and these are linked to the velocity of the fluid.
By profiling the flow of a fluid through a pipeline, you can find out how it is likely to behave and from there you can narrow down your choice to a flow meter that best suits your application.