Calculating Flow Rate: Oil in a Pipe

In summary: The equations and variables involved are also mentioned. The solution approach of using the Reynolds number and Darcy friction coefficient is described, but the final result may be incorrect due to unit inconsistencies. More information is needed to provide guidance on the solution.
  • #1
Vidatu
66
0

Homework Statement



Oil flowing through a pipe, measured to be 135kPa 15m from the end and 88kPa discharging from the end. The diameter of the pipe is 1.5cm, the density of the oil is 876kg/m^3, and the dynamic viscosity is 0.24kg/m*s.
Find flow rate for:
a) horizontal
b) inclined 8 degrees
c) declined 8 degrees

Homework Equations



[tex] Re=V*D*\rho / \mu [/tex]
[tex] \Delta P = h_L * \rho *g [/tex]
[tex] h_L = f*(L/D)*(V^2)/(2*g) [/tex]
[tex] f=64/Re [/tex] (laminar flow only)

where:
Re = Reynolds Number
rho = density[tex] f=64/Re [/tex]
mu = dynamic viscosity
delta P = pressure loss
h_L = head loss
L = length
D = diameter
f = Darcy friction coefficient

The Attempt at a Solution


I solved for Re in terms of V, and for V in terms of f, and then I guessed f=0.0150 for a starting point. I got an Re of 13.8, indicating laminar flow, so I used [tex] f=64/Re [/tex] and iterated. However, my answer finally converged on f=12734.79 which doesn't look at all right. Am I doing something wrong?
 
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  • #2


Probably unit related. The equation for delta_p(your second equation) will have units in pascal.
 
  • #3


Vidatu said:

Homework Statement



Oil flowing through a pipe, measured to be 135kPa 15m from the end and 88kPa discharging from the end. The diameter of the pipe is 1.5cm, the density of the oil is 876kg/m^3, and the dynamic viscosity is 0.24kg/m*s.
Find flow rate for:
a) horizontal
b) inclined 8 degrees
c) declined 8 degrees

Homework Equations



[tex] Re=V*D*\rho / \mu [/tex]
[tex] \Delta P = h_L * \rho *g [/tex]
[tex] h_L = f*(L/D)*(V^2)/(2*g) [/tex]
[tex] f=64/Re [/tex] (laminar flow only)

where:
Re = Reynolds Number
rho = density[tex] f=64/Re [/tex]
mu = dynamic viscosity
delta P = pressure loss
h_L = head loss
L = length
D = diameter
f = Darcy friction coefficient

The Attempt at a Solution


I solved for Re in terms of V, and for V in terms of f, and then I guessed f=0.0150 for a starting point. I got an Re of 13.8, indicating laminar flow, so I used [tex] f=64/Re [/tex] and iterated. However, my answer finally converged on f=12734.79 which doesn't look at all right. Am I doing something wrong?

You need to show your work so we can give you guidance.

CS
 

1. How do I calculate the flow rate of oil in a pipe?

The flow rate of oil in a pipe can be calculated using the formula Q = A x V, where Q is the flow rate in cubic meters per second, A is the cross-sectional area of the pipe in square meters, and V is the velocity of the oil in meters per second.

2. What is the unit of measurement for flow rate?

The unit of measurement for flow rate is typically cubic meters per second (m3/s), but it can also be expressed in other units such as liters per second (L/s) or barrels per day (bbl/d).

3. How does the viscosity of oil affect the flow rate in a pipe?

The viscosity of oil affects the flow rate in a pipe by creating resistance to the movement of the oil. Higher viscosity oils will have a lower flow rate compared to lower viscosity oils, as they require more force to move through the pipe.

4. Can the flow rate of oil in a pipe change over time?

Yes, the flow rate of oil in a pipe can change over time due to various factors such as changes in pressure, temperature, and viscosity. It is important to regularly monitor and calculate the flow rate to ensure efficient and safe transportation of oil.

5. Are there any tools or devices that can help calculate the flow rate of oil in a pipe?

Yes, there are various tools and devices that can help calculate the flow rate of oil in a pipe, such as flow meters, pressure gauges, and temperature sensors. These instruments can provide accurate and real-time data to calculate the flow rate using the appropriate formula.

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