 Hello, Myself P. V. Ekhande, working as an assistant professor in Department of Mechanical Engineering at Vulture Institute of Technology, Solapur. Today, we are going to observe the study related to the hydraulic turbines and at the end of this session, the students will be able to understand what are the different types of hydraulic turbines. We will have the discussion related to introduction to the hydraulic turbine, classification of hydraulic turbine and working of Peltonville and Francis turbine. Basically, hydraulic turbines what these are? A hydraulic turbine is a machine which converts the pressure and kinetic energy of water into mechanical energy. Secondly, the mechanical energy is then converted into electrical energy by electrical generator for generation purpose. For this, we have the hydraulic turbines which has got the efficiency in the different manner and these hydraulic turbines are very efficient as compared to other types of turbines. Classification, basically hydraulic turbines are classified as one impulse turbine and other reaction turbine. Under the impulse turbine, we have the Peltonville and under the reaction turbine, we have the two types. First is the Francis turbine and second is Kaplan turbine. Impulse turbine and reaction turbine, basically these types are used for the different application of hydraulic power plant. The impulse turbine is mainly used for the power plant where the high head is available and reaction turbines are used where the medium head or low head is available. Now, what is meant by this head available? For that, there is a benchmark of the height in the meters from the datum level. If the height is more than 90 meters that is treated as a high head turbine or high head power plant. When the height is in between 15 meters to the 90 meter, it is treated as the medium head power plant and below 15 that head is considered as low head hydraulic power plants. For high head power plant, we can go for the impulse turbine means we can have the installation of Peltonville over there whereas for the other types that is the medium and low head, we have to go for the reaction turbine and think of the name of the impulse turbine and reaction turbine. So, name of the impulse turbine is Peltonville and name of the reaction turbine, there are two types one is Kaplan turbine and other is Francis turbine. Now, we will see the principle of Peltonville which is basically used for the high head type of the hydraulic power plant. Now, for this purpose the construction wise when we consider it consists of rotor which is provided with the runners means on the periphery of runner there are buckets or vents which has got the cup type of the shape and the shaft is located in between two journal bearings and this runner along with this bucket is covered by a simple cover which is not a sealed cover like reaction turbines. Now, when we consider this construction so this portion shows the cover over there this is the shaft for the turbine this is the runner portion on which the buckets are mounted. So, these are the buckets or the vents which has got the shape similar to the cup type and if we come to this location this is a spear which is used to control the flow of the water which is impinging on the buckets of the turbine and this is the deflector. So, we can have the deflection of the water flow with the help of this and this spear is installed at the end of the pipeline which is called a penstock or this is called the penstock bend water from the dam is coming from this side and it goes to the bucket portion through this nozzle. So, nozzle is a tapered portion conversion type of the tapered portion which is again converting the kinetic energy into pressure energy into kinetic energy because of its construction that is the change in the diameter over there or the change in the cross section over there means when the water flows from high cross section to the low cross section or the lesser cross section there is a increase in the kinetic energy at the cost of pressure. So, when we have the rotation of this wheel there is a change in the position of the spear when the spear comes in the outward direction there will be the more flow and when the spear comes in the inward direction the flow will be lesser and because of that the kinetic energy also increases or decreases and accordingly we can have the control over the rotation of the runner or ultimately the turbine portion. So, water when passes through this penstock end bend and passes through the nozzle portion there is a jet which is falling on the buckets of that runner or the buckets of the turbine portion. So, because of this fall of the fall of the jet of the water on this bucket the runner moves in the anti clockwise direction along with the buckets and the place of this bucket will be taken by the another bucket like that it goes on rotating and the place of the bucket at this location will be taken by the buckets which is next to that and because of this high speed water flow which is impinging on the bucket the runner or the shaft of that turbine will have the very high rotation. The rotation of this turbine is in the range of 5000 rpm to 15000 rpm because of that we will we will have the high energy generation with the help of this pelton wheel. After falling on this bucket then water is taken towards the tail raise which will be over here. So, there is there will be a opening at this location and through this the water passes to the tail raise portion and then that water will be taken to the agriculture purpose through the dam canals canals for the agriculture purpose. So, this is the construction and the working of this pelton wheel at the top side the braking jet is shown. So, this is a jet which stops the rotation of the runner when the jet of water falls in this direction on this bucket it will have the reaction opposite to this. So, this jet which is trying to rotate the wheel in the anticlockwise direction to this it will have the restriction or it will try to decelerate the speed of that and finally there will be stopping of the rotation of this hydraulic turbine or the runner portion. This is regarding the construction and working of pelton wheel. Now, we will see regarding the another type of the turbine which is called as a reaction type of the turbine under that there are two types one is the Francis turbine and other is the Kaplan turbine both are reaction turbines. We will see the study related to this in this what happens the construction wise when we consider this has got the involute shape for the casing which is similar to the centrifugal pump. So, this is the scroll casing portion which is the stationary portion and this portion central portion will have the rotation which is called as a runner that is provided with the vents over here these are the moving vents. So, vents which are shown over here with the thick line these are the moving vents along with the runner portion and the vents which are shown with the convergent type of the shown shape over there these are the guide vents and these guide vents are mounted on the rim or the ring which is a fixed one. We can have the change of the angle or change of the position of these fixed blades or guide vents. So, these are not rotating these are the vents which are stationary over there but we can have the change in the angle of this because of that what will happen the water which is flowing through this passage its flow will be through the different cross section when you have the reduction in the angle there will be enlargement of the cross section when we will have the enlargement of the angle there will be reduction in the cross section over here that acts as a convergent shape which is helping the water flow to converts its pressure energy into the kinetic energy. So, like this in addition to the conversion of pressure energy into the kinetic energy through this casing portion the further kinetic energy is generated because of passing through the passage which is which is provided the due to the two vents in between these two vents there are convergent zones through which when it passes there is a increase in the again kinetic energy at the cost of pressure energy. Now, suppose water is flowing from this end so water which is stored in the dam portion will be taken through this penstock and the penstock end is connected to this water flows through this it passes through the place which is available space available over here that is a casing in between the casing and the rim portion when water passes to this after that it goes to the central location through the guide vents and then over the moving vent. So, due to passing of the water through this towards the vents over here there is a high speed generated to this rotor and it further increases again in this also we can have the very high speed in the range of 5 to 15000 or it may be more in some cases depending upon the bearings which are provided over there or the type of the power plant. So, this is regarding the working of the Francis turbine again I repeat the water comes through this it passes towards the conversion zone in between the casing and the rim portion afterwards it passes through the conversion zone which is generated because of the two vents position and then it goes to the guide vent and from guide vent from the central location through the draft tube it passes to the tail raise and from the tail raise it goes to the again canal through which the water can be again taken to the agriculture purpose means we can have the use of that water for the agriculture purpose after getting its power with the help of these hydraulic turbines. So, this is regarding the construction of working construction and working of Francis turbine hope you understood properly. Thank you.