Fluid dynamics - mass flow rate -dimensionless number

AI Thread Summary
Low mass flow rates, such as 2g/s, can lead to negligible friction and other losses in piping, particularly when considering the flow characteristics. Euler's dimensionless number may not be the appropriate metric to analyze these losses; instead, non-dimensionalizing the governing equations is recommended to identify the relevant terms. The discussion emphasizes the importance of understanding the driving forces in fluid dynamics, particularly at low flow rates, where vapor pressure may play a significant role. Participants encourage attempts at problem-solving to facilitate better guidance. Overall, engaging with the equations and concepts is crucial for a deeper understanding of fluid dynamics in this context.
JB Mandengue
Messages
10
Reaction score
0
(a) Is it true that if the mass flow rate of a gas is low, say 2g/s (grams per second), the friction losses and other losses in the piping will be negligible?

(b) If it is true that losses in the piping are negligible, is it the Euler's dimensionless number that we can use to prove this?

(c) If it is the Euler's dimensionless number, please indicate the proof. If it is not Euler, which one is it?

(d) Is it true that at such low mass flow rates, the main driving force is the vapour pressure of the gas?
 
Engineering news on Phys.org
If this is homework, please move it to the homework forum.

Thanks
Matt
 
At least throw an attempt and we'd be more likely to help you. Have you non-dimensionalized the governing equations? What terms do you see as constants?
 
minger said:
At least throw an attempt and we'd be more likely to help you. Have you non-dimensionalized the governing equations? What terms do you see as constants?

I haven't tried anything. I am looking for leads to point me in the right direction. The information I put about Euler is what I think it might be conceptually. But actually working it out I haven't tried.
 
Well as I mentioned, non-dimensionalize the equations, using standard non-dimensional terms and you immediately see what terms are driving. What terms can be driving if certain conditions are met.
 
How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...
Back
Top