Question
A pipe friction experiment is to be designed, using water, to reach a Reynolds number of 100,000 . The system will use 5 -cm smooth PVC pipe from a constant-head tank to the flow bench and $20 \mathrm{m}$ of smooth 2.5 -cm PVC line mounted horizontally for the test section. The water level in the constant-head tank is $0.5 \mathrm{m}$ above the entrance to the 5-cm PVC line. Determine the required average speed of water in the 2.5 -cm pipe. Estimate the feasibility of using a constant-head tank. Calculate the pressure difference expected between taps $5 \mathrm{m}$ apart in the horizontal test section.
Step 1
The Reynolds number is given by the formula $Re = \frac{\rho VD}{\mu}$, where $\rho$ is the density of the fluid, $V$ is the velocity of the fluid, $D$ is the diameter of the pipe, and $\mu$ is the dynamic viscosity of the fluid. Show more…
Show all steps
Your feedback will help us improve your experience
Chai Santi and 87 other educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
An air-pipe friction experiment consists of a smooth brass tube with $63.5 \mathrm{mm}$ inside diameter, the distance between pressure taps is $1.52 \mathrm{m}$. The pressure drop is indicated by a manometer filled with Meriam red oil. The centerline velocity $U$ is measured with a pitot cylinder. At one flow condition, $U=23.1 \mathrm{m} / \mathrm{s}$ and the pressure drop is $12.3 \mathrm{mm}$ of oil. For this condition, evaluate the Reynolds number based on average flow velocity. Calculate the friction factor and compare with the value obtained from Eq. 8.37 (use $n=7$ in the power-law velocity profile).
A straight smooth pipe $100 \mathrm{~mm}$ diameter and $60 \mathrm{~m}$ long is inclined at $10^{\circ}$ to the horizontal. A liquid of relative density $0.9$ and kinematic viscosity $120 \mathrm{~mm}^{2} \cdot \mathrm{s}^{-1}$ is to be pumped through it into a reservoir at the upper end where the gauge pressure is $120 \mathrm{kPa}$. The pipe friction factor $f$ is given by $16 / \mathrm{Re}$ for laminar flow and by $0.08(\operatorname{Re})^{-1 / 4}$ for turbulent flow when $\mathrm{Re}<10^{5}$. Determine $(a)$ the maximum pressure at the lower, inlet, end of the pipe if the mean shear stress at the pipe wall is not to exceed $200 \mathrm{~Pa} ;$ (b) the corresponding rate flow.
The 100 -mm-diameter pipe is connected by a nozzle to a large reservoir of air that is at a temperature of $40^{\circ} \mathrm{C}$ and absolute pressure of $450 \mathrm{kPa}$. If the backpressure causes $\mathrm{M}_{1}>1$, and the flow is choked at the exit, section 2 , when $L=5 \mathrm{~m},$ determine the mass flow through the pipe. Assume a constant friction factor of 0.0085 throughout the pipe.
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD