## Laminar Flow and Digital Flowmeters: An Explanation On How To Achieve Laminar Flow

When I see turbulent flow vs. laminar flow I vaguely remember my fluid dynamics class at the University of Cincinnati.  A lot of times when one thinks about the flow of a liquid or compressed gas within a pipe they want to believe that it is always going to be laminar flow. This, however, is not true and there is quite a bit of science that goes into this.  Rather than me start with Reynolds number and go through flow within pipes I have found this amazing video from a Mechanical Engineering Professor in California. Luckily for us, they bookmarked some of the major sections. Watch from around the 12:00 mark until around the 20:00 mark. This is the good stuff.

The difference between entrance flow, turbulent flow and laminar flow is shown ideally at around the 20:00 mark.  This length of piping that is required in order to achieve laminar flow is one of the main reasons our Digital Flowmeters are required to be installed within a rigid straight section of pipe that has no fittings or bends for 30 diameters in length of the pipe upstream with 5 diameters of pipe in length downstream.

This is so the meter is able to measure the flow of compressed air at the most accurate location due to the fully developed laminar flow. As long as the pipe is straight and does not change diameter, temperature, or have fittings within it then the mass, velocity, Q value all stay the same.  The only variable that will change is the pressure over the length of the pipe when it is given a considerable length.

Another great visualization of laminar vs. turbulent flow, check out this great video.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 -Fluid Mechanics: Viscous Flow in Pipes, Laminar Pipe Flow Characteristics (16 of 34) – CPPMechEngTutorials – https://www.youtube.com/watch?v=rQcZIcEa960

2 – Why Laminar Flow is AWESOME – Smarter Every Day 208 – SmarterEveryDay – https://www.youtube.com/watch?v=y7Hyc3MRKno

## Line Vac Helps Students With Automation Projects

Over the past year I received a contact from a professor and student combination from Madison Area Technical College inquiring about the sizes available for our Line Vac products.  They were using a 2″ Line Vac in one of their automation class labs and wanted to try something a little bigger for a new project.  The 2″ Line Vac was one they had used in the past on different projects and had always worked well.   The new project however increased the bag size and made the conveyance difficult for the 2″ Line Vac.

With the picture below of their current setup and a good understanding that they will be placing three items into a heat sealed bag that is roughly 3″ long and 2″ wide we settled on using the 3″ Aluminum Line Vac at a low pressure to convey the baggies to their secondary function.   As you can see in the video below, the Line Vac is activated by a sensor and operates for just seconds in order to convey the bag of parts successfully to the other side of the machine cell where the bag is then picked and placed by a robotic arm.

After the project was completed we received a mention through social media, as well as a brief video showcasing the Line Vac in use.  The video showcases how easy it is to install an EXAIR Line Vac into a tight space where adding other conventional mechanical conveying systems would be considerably more elaborate.  The Line Vac is being controlled via a PLC that energizes a solenoid valve on a timer to convey the package in a matter of seconds.

We are very pleased to see the projects these kids turned out, and the leadership shown by Peter, their instructor. Manufacturing programs such as this one at Madison Area Technical College are important for our economy and for the future of these kids. We’d like to congratulate them all on their accomplishment.

If you have a project you are trying to move products from one point to another, contact us.  If you are a professor, student, or even a mentor to an educational program that would benefit from EXAIR products, please contact me directly.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF