Homework SourseStudents in a fluid mechanics class at Old Dominion Universi
Students in a fluid mechanics class at Old Dominion University have been requested to assist engineers in the Buildings and Grounds Department (BGD). BGD engineers want to pump water from the fountain in front of Webb Center up to a sealed tank on top of Kaufman Hall, which is a vertical distance of 6 meters from the free surface of the water in the fountain to the free surface of the water in the tank. The sealed tank is pressurized to a constant pressure. It is required that the water be transported at the rate of 550 m3 in one day or less. The water flows through a 2-in. diameter pipe cast-iron pipe, 4 regular 90° threaded elbows, and 2 fully-open angle valves. You can assume that the distance from the fountain to the base of Kaufman is 50 meters, so that the total length of pipe is 55 meters, providing for a depth of water in the tank of 1 meter. The BGD engineers want to know if a 2500 W pump is sufficient to accomplish the task if the sealed tank is pressurized to: a. 0.5 atmosphere b. 2 atmospheres c. 1 atmosphere Calculate or present the values of the following variables for part a) above, and draw a box around them: 1. A sketch of the flow system 2. The full modified Bernoulli equation 3. Assumptions made to the modified Bernoulli equation 4. The value of the volumetric flow rate in m3/s 5. The value of the flow velocity in the pipe in m/s 6. The value of the flow Reynolds number 7. The value of the friction factor, f 8. The total sum of the minor loss coefficients, KL 9. The value of the available pump head, hp)avaukabke in meters, based on the pump specifications 10. The value of the required pump head, hp)required in meters, calculated from the modified Bernoulli equation 11. Your recommendation to the BGD engineers Calculate only the value of the required pump head for parts b) and c) and your recommendations to the BGD engineers for those parts.
Solution
Students in a fluid mechanics class at Old Dominion University have been requested to assist engineers in the Buildings and Grounds Department (BGD). BGD engineers want to pump water from the fountain in front of Webb Center up to a sealed tank on top of Kaufman Hall, which is a vertical distance of 6 meters from the free surface of the water in the fountain to the free surface of the water in the tank. The sealed tank is pressurized to a constant pressure. It is required that the water be transported at the rate of 550 m3 in one day or less. The water flows through a 2-in. diameter pipe cast-iron pipe, 4 regular 90° threaded elbows, and 2 fully-open angle valves. You can assume that the distance from the fountain to the base of Kaufman is 50 meters, so that the total length of pipe is 55 meters, providing for a depth of water in the tank of 1 meter. The BGD engineers want to know if a 2500 W pump is sufficient to accomplish the task if the sealed tank is pressurized to: a. 0.5 atmosphere b. 2 atmospheres c. 1 atmosphere Calculate or present the values of the following variables for part a) above, and draw a box around them: 1. A sketch of the flow system 2. The full modified Bernoulli equation 3. Assumptions made to the modified Bernoulli equation 4. The value of the volumetric flow rate in m3/s 5. The value of the flow velocity in the pipe in m/s 6. The value of the flow Reynolds number 7. The value of the friction factor, f 8. The total sum of the minor loss coefficients, KL 9. The value of the available pump head, hp)avaukabke in meters, based on the pump specifications 10. The value of the required pump head, hp)required in meters, calculated from the modified Bernoulli equation 11. Your recommendation to the BGD engineers Calculate only the value of the required pump head for parts b) and c) and your recommendations to the BGD engineers for those parts.
