In this video, I explain types of nozzle. First one is the conversion nozzle. Second one is the diversion nozzle. And third one is the combine of both. That is called as the conversion-diversion nozzles.
So, this is the figure of conversion-diversion nozzles. And I also explain what is Mach number, what is sonic flow, subsonic flow, supersonic flow and hypersonic flow. So, you can understand this topic easily.
So, first we understand the convergent nozzle. So, in a convergent nozzle what happen? The cross section area of the nozzle increase continuously from inlet to exit it is called as the convergent nozzles. In a some book instance of the inlet entrance are mentioned.
Now, here in this diagram you see this side is the inlet and this is the outlet. Okay, means the fluid is entered from this side and the fluid is outlet from these sides okay and here you see that is the highest cross sectional area is there and when we move ahead means the when the fluid is move ahead at that time this cross sectional area is reduced okay so here we mention cross sectional area of nozzle is increased so here you see this cross sectional area is increased when we see this nozzle from the side view we can see that is a two circle here we see the small circles and here we see the larger circles in a conversion nozzle the velocity is always less than sonic velocity hence it is also called as the subsonic nozzle so here velocity is less than sonic that's why it is called as the subsonic nozzles now what is the sonic velocity what is subsonic velocity that you need to understand okay so here you see first we need to understand what is the mach number okay means on the basis of mach number the flow is classified either it is a subsonic, sonic, supersonic or hypersonic. So, that is the simple equations of the Mach number that is the object speed divided by speed of sound. Means here the steam is flowing from the nozzle then the velocity of steam divided by velocity of sound.
Means if object velocity and the sound velocity are same. At that time this Mach number is 1 and when the Mach number is 1 it is called as the sonic velocity. When this Mach number is less than 1 it is called as the subsonic.
Means when this Mach number is less than 1, Mach number is less than 1 means the velocity of fluid is less than the velocity of sound. Then it is called as the subsonic. Supersonic means the Mach number is greater than 1. When this Mach number is greater than 1, the velocity of fluid is higher than the velocity of sound and this Mach number is called as the supersonic or the Mach number is greater than one and hypersonic if this Mach number is greater than five means the speed of sound means velocity of the sound is 343 meter per seconds okay so when this flow is called hypersonic means velocity of a object or the velocity of fluid is five times than the speed of sound or the velocity of the sound okay so velocity of the sound is 343 so 343 into 5 times means velocity of the object is higher than the 5 times of the sound velocity then this Mach number is 5 and Mach number is 5 or greater than 5 then it is called as the hypersonic flow means here in this conversion nozzle the fluid inlet velocity is the sonic velocity. Sonic velocity means its Mach number is equal to 1. But here what we mention it is the less than 1. Less than 1 means the it is a subsonic means the velocity of the fluid is less than the velocity of sound means velocity of the fluid is less than 343 meter per second. At that time we need to use this conversion nozzles and this velocity is further increase towards this outlet.
And it is converted into the sonic velocity. So, here this velocity of the fluid enter is less than the sonic velocity. That's why it is called as the subsonic nozzles.
So, at the smallest section, smallest section means this section and this smallest section is also called as the trot. The velocity becomes sonic velocity. So, here sonic velocity means the velocity of the fluid is similar as the velocity of sound means the velocity is 340. 3 meter per second.
Now the second nozzle is the diversion nozzle. When the cross section area of nozzle increase continuously from inlet to exit it is called as the divergent nozzle. Now here you see it is the diagram this is the inlet this is the outlet and in the direction of flow the cross-section area of the nozzle is increasing that's why it is called as the divergent nozzle means it is opposite to the convergent nozzle in a convergent nozzle what happened the cross-sectional area is increased in a divergent nozzle the cross-section area is increased In a diversion nozzle, the velocity is more than sonic velocity. Sonic velocity means Mach number is 1. And here what we mentioned more than sonic velocity means Mach number is greater than 1. It is called as the supersonic. So, in this diversion nozzle, the steam flowing and the steam have a Mach number is greater than 1 and Mach number is greater than 1 means the steam.
have a velocity is higher than the velocity of the sound means the velocity of the steam is higher than 343 meter per seconds now before moving it i request to like the video and subscribe my channels for watching the more video related to power plant engineering and other subject of this mechanical engineering for power plant engineering where is link is provided in descriptions as well as in a car for other subject i request to visit the playlist. Now third type is the conversion diversion nozzle means it is the combination of conversion as well as the diversion nozzle means first cross-sectional area of the nozzle is increased from its inlet to throat and then cross-sectional area is increased from throat to exit it is called as the conversion diversion nozzle as shown in this figure means first part here it is the inlet okay and cross sectional area is initially increased means this is the conversion nozzle and this part is called throat means here it is minimum area so it is called throat and from the throat again the area is start to increase then it is called as the conversion diversion nozzle means it is the combination of conversion plus diversion nozzle that's why it's called as conversion diversion nozzle so this is the inlet side and this is the outlet side in practice pressure of steam at the inlet to this converging portion means at this portion the pressure of steam is very high and the velocity is negligible means at the entire entry point of this conversion diversion nozzle pressure is high velocity is low and then what happened this velocity is increased in a converging portion means in this converging portion the velocity is increased so that the velocity becomes sonic at the throat means at this point the velocity becomes sonic now what is the meaning of sonic sonic means the velocity is same as the velocity of sound and then after further expansion of a steam is takes place in this diverging nozzle means in the diverging nozzle the steam is further expand and during this expansion what happen so that the velocity become supersonic in the diverging portion means in this diverging portions the at the input of this diverging portion the velocity is the sonic and it is converted into the supersonic in this diverging portion So, thank you for watching this video. If you learn something then like the video, subscribe my channel and don't forget to share with your friends.