
(a)
The maximum power generated by the wheel at 80% efficiency.

Answer to Problem 11.97P
The maximum power generated by the wheel at 80% efficiency is 9.36 MW.
Explanation of Solution
Given:
Referencing the below diagram:
We have:
Concept Used:
The maximum power for an impulse turbine can be obtained when,
Where:
Calculation:
For the head, we have steady flow energy equation:
But the friction head loss of pipe:
Hence, the head is:
Where,
- f = friction factor
- = velocity of pipe Now, using continuity equation:
Where,
- = diameter of jet
- = cross section area of pipe
- = area of jet
- D = diameter of pipe Now putting the values of H, L, D and
The Reynolds number:
The ratio is:
From Moody’s equation:
By solving equation (2) & (3), we get
The volume flow rate is,
The maximum power for the impulse wheel can be obtained for
For determining maximum power:
The maximum power generated by the wheel at 80% efficiency is 9.36 MW.
Conclusion:
The maximum power generated by the wheel at 80% efficiency is 9.36 MW.
(b)
The best speed should be determined for given impulse wheel.

Answer to Problem 11.97P
The best speed of the wheel is 272.3 r/min.
Explanation of Solution
Given:
Referencing the below diagram:
We have,
Concept Used:
The equation given below is also taking into consideration:
Calculation:
For getting speed of wheel:
Converting the rad/s unit of speed to r/min as follows:
The best speed of the wheel is 272.3 r/min.
Conclusion:
The best speed of the wheel is 272.3 r/min.
Want to see more full solutions like this?
Chapter 11 Solutions
Fluid Mechanics
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY





