Francis turbines are the most preferred hydraulic turbines. It contributes about 60% of the global hydro power capacity mainly because it can work efficiently under wide range of operation conditions. The most important part of a Francis turbine is its runner. It is fitted with complex shade blades. In the runner, water enters radially and exits axially. During the course of flow, water goes through the runner blades. Francis turbine blades are specially shaped. We can note that blades are having thin airfoil cross section. So, when water flows over it, low pressure will be produced on one site and high pressure in the other site. This will result in a lift force. We can also note one more peculiar thing about the blade. It is having a bucket kind of shape towards the outlet. So, water will hit, and producing impulse force before leaving the runner. Both impulse force and lift force will make the runner rotate. So Francis turbine is not a pure reaction turbine. A portion of force come impulse action also. Thus, when water flows over runner blades, both its kinetic and pressure energy will come down. Since flow is entering radially and leaving axially, they are also called mixed flow turbine. Runner is connected to the generator via shaft for electricity production. This arrangement is fitted in a spiral casing. Flow enters via inlet nozzle. Flow rate of water will get reduced along length of casing, since water is drown into the runner. But decreasing area of spiral casing will make sure that water flow is entered to runner region almost at uniform velocity. Stay vanes and guide vanes are fitted at the entrance of runner. The basic purpose of them is to convert one part of pressure energy to kinetic energy. Flow which is coming from the casing meets stay vanes, they are fixed. Stay vanes steers the flow towards runner section. Thus, it reduces inlet flow. Demand for power changes over time. The guide vane mechanism is used to control flow rate and make sure that power production is synchronized with power demand. Apart from controlling flow rate, guide vanes also control flow angle to inlet portion of runner blade. Thus, guide vanes make sure inlet flow angle is the optimum angle of attack for maximum power extraction from fluid. Low pressure at the outlet of the turbine may cause serious problems of cavitation. So, a special draft tube is designed is fitted at exit site to discharge the fluid out. Draft tube will transform velocity head to static head due its increasing area that will reduce effect of cavitation.

Man...what a lesson...just spent 30 min watching a 4 min video, quality information, you have my respect!!!

Very helpful for my engineering degree. God I love You Tube, there's so many mechanisms that a 2-D page just can't do justice to. Many thanks.

Great animation. It's insane how they have up to 95% efficiency.

totally agree to the comment of the XBuryBoy, by seeing this animation maake me instantly understand the working of the Francis engine than reading the two pages on my course book. Thank you Learn engineering

EXCELLENT DEMONSTRATION.REALLY CLEARED MY DOUBTS ABOUT FRANCIS TURBINE.THANK U SO MUCH

excellent video! clear, to the point, helpful visuals

I worked in the original mechanical design of 2 power plants of the Calf State Water Project, Oroville and Thermalito. This brings back memories.

Very well explained. I was so much confused between Guide vane and Stationary vane. Also was confused about its flow. Thanks for this awesome video.

Excelente ilustração de funcionamento da turbina Francis. Obrigado!

Awesome video. As a mechanical engineer I like the way this is explained. Thanks!

Quite satisfied. Extraordinary explanation!

Thank you so much for all the team members.🙏💐

Thanku so much to the team of learn engg. For making us feel of what we study in engineering..

very good.easy to understand while explaining along with visual.Thanks a lot.

Thanks for an amazing demonstration.

what a remarkable presentation of Francis turbine

How well explained , love this channel

cool animation, simple explanation simply stunning.

It such a more help full for me to better understand that how its work and what mechanism should be helps to rotates the runner. Thank you very much...

Wow...this is very well explained. Thank you so much..I really needed this knowledge at this time of the year.

really good video, better explained than my Teacher XD

Really awesome video !! it's really very helpful video for every engg studenst..thank u so much...

It's very nice and useful video. Clear explanation is given. Thank you.

Great video! Solved all my doubts

Thank you for the video. It was very infromative.

Awesome explanation. THANK YOU

good thoughts with explanation for students . thank you .

A superb video ... Very helpful ... Thank You

thanks. nice explanation now i understood this concept.

Thank you , it was very helpful.

superb explanation

Thank you so much for making this video😇

Hodgson Water Mill in Sycamore, Missouri is a great example of early use of the Francis Turbine. Built in 1894 by Alva Hodgson, the grist mill used not one, but two francis turbines to power the facility.

Thanks for the useful information.

outstanding explanation

Very Helpful-Thank you

nice explanation. thanks LE

No. Some popular science explanation is need.. The draft tube gradually widens in area and slows the fluid down before it exits. Slower speed means something has to hold the horses back and the only way that could happen is a pressure gradient. Each tiny flow element will have to feel an external net force reducing its speed. The only way to have a net force that affects speed is to feel more pressure on your face than on your back. As the first guy exiting the draft tube enters free air with his "face pressure" only defined by the water depth of exit, the gradual pressure forces will pile up like in a battery stack and you will have the minus pole of the pressure gradient sum at the inlet of the draft tube. So the draft tube is a pressure battery stack driven by kinetic energy and introduces much wanted reduced pressure at the turbine exit. A side effect is any factor of cavitation will increase. If the design is subject to cavitation you can add static pressure to the turbine by placing it as low as practically possible, sometimes located far below the water level of the exit.

Good job brother...love your hard work😍😍

Beautifully described

Great work!

Thank You very much, Very useful info

Video presentation is good and easy to understand..

Thank you so much for video sir👌👌

Nice animation & Explanation Thank You so much Sir ❣️❣️❣️😊

Brother thankyou very much ..keep the good work going

Greatly explained

it was very helpful.. thank you

thank u so much. it is very helpful to me

Really helpfull for my internals because i usually dont listen to classes

It was very informative for me.

it's really helpful.tqs for the upload

very helpful sir.Thankyou

Very good and simple presentation for the beginner, I sincerely thank the LearnEngineeringTeam. All the Best.

I have got clear idea draft tube and their action...... thanks everybody to support us for new learner ..........

Very well explained Sir

Very good session thank you

Very nice and informative video

Thanks a low, great explanation

love from India sir❤

thanking each and everyone who worked to develop this video .

very helpful for my engineering degree ..................................

Wow! Very well explained. We presume the voice is that of a robot as the grammar is quite different and appears to lack continuity. Thanks for the video and best of luck.

great, very helpful !! can you make a vido explaining the design of the blades of a compressor wheel please ?

very nice very informative easy to understand: ramesh kulkarni

I felt as if i am in powerhouse and watching all the mechanisms in reality ❤️❤️.Best video ever for me. ❤️❤️🔥

Thanks deer very helpful click

That's very good informations thanks

Question: if U put a number of these in series within a surtain hight, and then close the loop with 1 pump pushing the water back strait up to the top could those vortex generetors produce motor power than the 1 pump needs? thus creating excess (free) power

thank you for ur tips

very smoothly explained...superb work..!!👍

Amazing..Thanks

My mechanical engineering staff ever... thank u respected team

This is great. Maybe you could reuse the model to illustrate the Leffel Turbine which I think adds an axial flow stage below the Francis Turbine.

شكرا شرح مفيد 🌸

Beautiful!!!!

Thank You. Thank You.Thank You.Thank You. Very Much.

Awsome.....thanks sir👌👌👌🙏🙏🙏

Thanks to share your best knowledge and one question I want to ask you u how lift generation in vanes due to its aerofoil shape

What are you using for animation, It is amazing !!

3D made it super easy to understand

I feel like this entire video’s script had all of its instances of the word “the” removed.

Can we use this design for air compressor which takes in air radially and throws out axially?

tercüman arkadaşıma da özellikle teşekkür ederim.

Thanks . Now I now how it works .I see some improvements can be made . But for now in 2019 it will be fine .

very useful....

Nice teacher

very helpful

Super explaination but I need to know in deep and very keen information from point to point how turbine is been prepared and which type of material is been used

nicely presented..!!(Y)

great to see the views in 3-D

Can u explain the electrical mechanism for some case that turbine also work as motor for pumping water ?

good work

Excellent

Thank you very much

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thanks a lot man

just awesome

This is in my recommended