Q3.10: Power Calculation w/ Reduction Gear

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Discussion Overview

The discussion revolves around a homework problem related to power calculations involving a reduction gear system. Participants explore the application of torque and angular velocity in calculating power, as well as the implications of resisting torque in a turbine system.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Conceptual clarification

Main Points Raised

  • One participant expresses difficulty in calculating the second and third answers of the problem, indicating a lack of understanding in the application of relevant equations.
  • Another participant suggests using the same expression for part b) as was used for part a), highlighting the availability of torque (##\tau##) and angular velocity (##\omega##).
  • A question is raised about how to determine the value of torque, specifically whether it should be the resisting torque of water or the torque provided by the turbine shaft, or a combination of both.
  • Participants discuss the significance of the third part of the problem, with one noting that it is straightforward but indicates a need for gearbox cooling.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the value of torque to use in calculations, and there is uncertainty regarding the significance of the third part of the problem. Multiple viewpoints on these aspects remain unresolved.

Contextual Notes

There are limitations in the assumptions made regarding the torque values and the implications of the calculations, which are not fully explored in the discussion.

Suman_babai
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Homework Statement

: [/B]
Qstn no. 3.10 in the attached image.

upload_2016-12-20_8-9-45.png

[ Moderator note: Copy of relevant portion of attachment inserted to make it visible here]

Homework Equations

: For power calculation, [/B]
Power = torque * angular velocity... Also, reduction gear is used to deliver lower outout speed at samd torque.

The Attempt at a Solution

: [/B]
I have tried the above equations and also correctly calculated the 1st ans(2nd attachment) but I can't calculate the 2nd and 3rd ans... I hv approached the second one but ans is not matching.. pls help... also please explain it.. as i am very weak in it...
 

Attachments

  • 1482219135110-834241603.jpg
    1482219135110-834241603.jpg
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  • 1482220028136-2067728740.jpg
    1482220028136-2067728740.jpg
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Last edited by a moderator:
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Hello Suman, :welcome:

why not use the same expression for b) as you use for a) ? You have ##\tau## and you have ## \omega## !
 
BvU said:
Hello Suman, :welcome:

why not use the same expression for b) as you use for a) ? You have ##\tau## and you have ## \omega## !

Yes.. but.. what is the value uf torque here ?
BvU said:
Hello Suman, :welcome:

why not use the same expression for b) as you use for a) ? You have ##\tau## and you have ## \omega## !

Yes I know. But how can I get the torque? If it is the resisting torque of water, then where goes the torque given by the turbine shaft ? Or will it be the difference between the above mentioned torques ?
 
Suman_babai said:
If it is the resisting torque of water
For want of better you could start with that assumption ...
Suman_babai said:
where goes the torque given by the turbine shaft
That is a nice subject for part (c) :rolleyes:
 
BvU said:
For want of better you could start with that assumption ...
That is a nice subject for part (c) :rolleyes:

Ok I get the 2nd prt... and also the 3rd prt... thnks a lot.. but what is the significance of the 3rd part?
 
It's a giveaway: subtract 14.235 from 15. Too easy ! But it shows the gearbox needs cooling :smile:
 
BvU said:
It's a giveaway: subtract 14.235 from 15. Too easy ! But it shows the gearbox needs cooling :smile:
Yes I know the mathematical prt. I jst wanted to know to know its significance... thank you very very much.
 

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