Fluid Flow Calculation for Gravity-Driven System: Velocity and Pipe Diameter

AI Thread Summary
The discussion revolves around calculating the velocity and pipe diameter for a gravity-driven water flow system with specific parameters. The user is trying to determine the flow characteristics for 20 m³/h of water flowing 15 meters down a 50-meter pipe. There is a mention of using Bernoulli's equation, with a note that it is applicable only when fluid viscosity can be neglected. Participants suggest considering viscosity in the calculations and emphasize the importance of understanding the relationship between flow rate, velocity, and cross-sectional area. The conversation highlights the complexities involved in fluid dynamics calculations for such systems.
birddog
Messages
2
Reaction score
0
Hello there,

Im trying to figure this assignment question and I have hit hurdle. Can someone please help with figuring out what the velocity and pipe diameter will be??

Question:
In a plant 20m3(cubic)/h of water at 20 degrees C is to flow via gravity from a storage tank to another one. the difference in elevation is 15m and total pipe length is 50m.

I thought it would be 9.81 m/s because of gravity but that seems too fast.
Can someone please help.

Thanks in advance!
 
Physics news on Phys.org
i would give bernoulli's equation a try

p + \frac{1}{2} \rho v^2 + \rho g h = \rm{const}​
remember:

\dot V = \frac{v}{A}​
 
Just to be technical on this.

Bernoulli's equation only works well if the viscosity of the fluid can be neglected.

Follow saunderson's post. I just wanted to throw the viscosity bit in.

Thanks
Matt
 
Last edited:
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top