Answer: Hydraulic Efficiency of a Pelton Turbine

  • Thread starter skpmech
  • Start date
  • Tags
    Turbine
In summary, the efficiency of a turbine, specifically a pelton turbine, is calculated by dividing the power developed by the runner or shaft power by the water power. The formula for shaft power is the mass flow rate multiplied by the sum of the velocity at the inlet and outlet, and the velocity at the inlet and outlet multiplied by the specific speed. The formula for water power is the density multiplied by the acceleration due to gravity, the flow rate, and the head. The question asks about the use of the formula 0.5*m*V^2 for calculating water power, as opposed to the formula given by the teacher, which is density*g*Q*H. It is unclear what the variable m represents, whether it is the
  • #1
skpmech
1
0
The hydraulic efficiency of a turbine (let pelton turbine) is given by - (power developed by runner or shaft power)/(water power)

shaft power is - (mass flow rate)*(Vw1+Vw2)*u

water power is - density*g*Q*H

My question is that the pressure head is converted into kinetic energy in nozzle then we should use water power = 0.5*m*V^2
why we use that formula.

my teacher said that energy input to runner= 0.5*m*V^2
and energy input to whole turbine system = density*g*Q*H
please explain.
 
Physics news on Phys.org
  • #2
Not sure I follow your question but..

density*g*Q*H ... That looks like the equation for the theoretical power available from something like a dam. It depends on the density, gravity, height and flow rate. Presumably Q is the flow rate?

The KE of a mass m coming out of the pipe will be 0.5*m*V^2 but power = energy/time. So is m the mass or flow rate?
 

What is a Pelton Turbine?

A Pelton Turbine is a type of hydraulic turbine used for the conversion of water into mechanical energy. It consists of a runner with spoon-shaped blades that are driven by the force of water from a high-pressure source, such as a dam or reservoir.

How does a Pelton Turbine work?

A Pelton Turbine works by directing a high velocity jet of water onto the blades of the turbine, causing it to rotate. The energy of the water is converted into mechanical energy, which can then be harnessed to generate electricity.

What factors affect the efficiency of a Pelton Turbine?

The efficiency of a Pelton Turbine is affected by several factors, including the design of the turbine, the speed of the water jet, the quality of the water, and the altitude and temperature of the location where the turbine is installed.

How is the efficiency of a Pelton Turbine measured?

The efficiency of a Pelton Turbine is measured by the ratio of the actual power output to the theoretical power output. This is known as the hydraulic efficiency and is expressed as a percentage.

What are the advantages of using a Pelton Turbine?

The main advantages of using a Pelton Turbine are its high efficiency, ability to operate at low flow rates, and its simple and robust design. It also has a long lifespan and can be easily maintained, making it a cost-effective option for hydropower generation.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
1
Views
689
  • Engineering and Comp Sci Homework Help
Replies
5
Views
3K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
3K
  • Mechanical Engineering
Replies
6
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
5
Views
3K
Replies
8
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
2K
  • General Engineering
3
Replies
72
Views
8K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
3K
  • Mechanical Engineering
Replies
9
Views
2K
Back
Top