Thrust power

Just out of curiosity, is there a way to calculate efficiency without further data? It seems you would need the propeller geometry or at least one or more data values.

 

Ad Hoc you have been extremely helpful. I can't thank you enough
Many thanks
Fran

 

Efficiency of what...?

 

I guess shaft power to propulsive power efficiency. OP question was "Also calculate the propeller thrust, efficiency, effective / delivered power"

It's not answerable right?

 

Ahh...ok...you mean of the OP's question.
Yes, in sufficient data. You can answer how to calculate it, in words, but there is insufficient data to actually calculate it. in numbers.

 

hi there, is there any way of calculating the BM of a ship using the following information; LCB 0.8439M aft of midships, waterplane area 201.113m2, displacement 85.47 tonnes, and waterline length 29.5M??

 

Yes

BM = I/V

 

Thanks ad hoc but which figure is I (moment of inertia)?

 

And there in lies the problem. The question you posted, doesn't have the 2nd moment of area of the waterplane. And there is insufficient information to calculate it.
Is there missing info?

 

Ad Hoc,
I have a table with the half areas and waterplane half breadths. I was able to use simpsons rule to work it out..
many thanks!!

 

Oh goodie.
Well done

 

Hello !
Noel, how is your progress with Unit 1 and Unit 2 Assignment ?)
Looking forward for your reply,
Roman

 

Hi Noel.







I know you started this thread a while ago. I have just started this course and the question has me stumped too. I was wondering about the other parts of the question like efficiency/ effective delivered power, was the lecturer looking for actual figures or just a text answer. Or am I over thinking it.
I am not sure if your going to see this, but any advise would be helpful.
Regards,
Robert McFadden

 

Hi Robert,

Welcome to the Forum.

FYI, Noel hasn't been on the Forum for over four years now....

BB

 

Thank you BlueBell.
I thought that might be the case, just posted in the offchance, that he might have got an email notification. I am doing the course he was doing, and the information at times seems to be abit sparse. Or I am looking too deeply at what is required.

Thank you.