1.5. Darcy-Weisbach Equation

Try these first

1. 1.

   What are the two types of losses in a piping system?

   Hint

   Think about losses due to friction and fittings.

2. 2.

   What does the friction factor depend on?

   Hint

   Recall how the flow type affects resistance.

3. 3.

   What is the equation representing the pressure drop in a pipe according to Darcy-Weisbach?

   • δP = f * (L/D) * (ρ * V^2 / 2)
   • δP = L / (f * D) * (ρ * V^3 / 2)
   • δP = (ρ * V^2) / (2 * gD)

   Hint

   Remember how friction and length relate in the equation.

4. 4.

   True or False: Major losses refer to energy losses due to fittings and bends in pipes.

   • True
   • False

   Hint

   Recall the definitions of major vs minor losses.

5. 5.

   You have a pipeline with a known diameter and length. If the flow rate and fluid properties yield a Reynolds number of 2500, calculate the head loss over a given length using the Darcy-Weisbach equation. Assume friction factor is obtainable from the Reynolds number tables.

   Hint

   Pay close attention to the units when converting for calculations.

6. 6.

   Calculate the diameter required to maintain head loss under 5% of the total head for a flowing water pipe of known length and friction factor, assuming turbulent flow.

   Hint

   You may use trial and error after initial calculations for precision.