Thermodynamics - Motor and pump efficiency

[@coolisfoolable]

Wow, this example is a real brain workout

[@wereleymereley7233]

Thank you very much for all these thermodynamics video :) it really helps

[@patrickbateman34]

Thank you for the video. I didn't understand how we understand that the flow rate remains constant and kinetic energy of the system changes.

[@emreyuksel8517]

Check out the bernoulli principle ,velocity and diameter relations

[@Anima0000]

Hello thank you for your videos, I've learned a lot from it❤❤

[@lenacoronado2172]

What textbook were you following for this video series?

[@engineeringdeciphered]

Thermodynamics, an Engineering Approach, by Cengel and Boles

[@blueberry2163]

god bless you ربنا يهديك لما يحب ويرضى

[@SaifUllah-uy6kz]

Thank you sooooo much. This is really helpful

[@mon4363]

It's really useful

[@yusufselcukcavdar4088]

Thanks

[@satazer5824]

Really helps, Thank you😃

[@guanhan898]

Ok so i understand that for the pump to increase the pressure of the water, the shaft or pump needs to put in work. But what about the kinetic energy? Why is it negative? Is this machine also a dam that can generate electricity?

[@chisomodimmegwa3479]

because there is change is kinetic energy due to difference in the pipe sizes, now we ask ourselves, is the energy change positive or negative, once you insert your values, you realise there is negative change which indicates a lose

[@guanhan898]

@@chisomodimmegwa3479 weird. If the inlet and outlet diameter is the same and we assume no other energy losses, then the wdot will be 50kW. So we need to slow down the speed of flow in order to use less work?

[@chisomodimmegwa3479]

@@guanhan898 m dot is ro x vdot. Vdot is VxA. With this it become obvious there is a change in kinetic energy because A is different for both diameters. So if V. For both diameters is the same the either A or V is definitely different. No lets try your theory of same Diameter. If diameter is same and Vdot is same for both pipes. Then i believe velocity will b the same because once again, Vdot is VxA

[@jktification]

Not understanding why the pump is responsible for KE loss. Seems like starting velocity is zero since pump causes the initial movement. Without the pump KE starts at zero. The pump isn’t slowing down the velocity of the static water in the reservoir. Can anyone explain what I’m not understanding?

[@chrisis1]

This is a good question. I believe the kinetic energy is a loss because of the conversion to pressure energy. Look at how a centrifugal pump works. KE is converted to pressure energy by the pump.