IP and MEP - whats the difference

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The Dieselduck
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IP and MEP - whats the difference

Postby The Dieselduck » Thu Feb 09, 2012 4:27 am

I got an email on IP and MEP, can anyone help, got my hands full in shipyard...

Martin


I got general doubt regarding MIP(Mean Indicated Pressure) and MEP(Mean Effective Pressure).
Is there any specific difference between these two terms?

From the indicator diagram of 2-stroke engine, we calculate the area; and divide it by length of indicator diagram and multiply by spring constant. This gives Pressure which is MIP or MEP?

Over the net, I could not find the difference. Either they mention it as Indicated Mean Effective pressure or simply mean effective pressure.

Thank you, sir. It would be great help for me.
Martin Leduc
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Martin's Marine Engineering Page
http://www.dieselduck.net

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Big Pete
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Re: IP and MEP - whats the difference

Postby Big Pete » Fri Feb 10, 2012 1:50 am

MIP, Mean Indicated Pressure, is the mean of the pressures recorded on the indicator diagram, calculated using a planimeter or electronically. Inputting this Pressure value into the PLAN formuala will enable you to calculat the Indicated Power.

MEP, Mean Effective Pressure is calculated backwards from the measured Brake power using the PLAN formuala. Where P is the pressure, L is length of stroke, A is area and N is Number of power strokes.

The Indicated Power and Pressure will always be greater than the MEP and Brake Power because of friction in the engine.

Hope this helps.

BP
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The Dieselduck
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Re: IP and MEP - whats the difference

Postby The Dieselduck » Fri Feb 10, 2012 12:35 pm

I will pass it on, thanks.
Martin Leduc
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http://www.dieselduck.net

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JollyJack
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Re: IP and MEP - whats the difference

Postby JollyJack » Wed Feb 15, 2012 5:26 am

As BP says, indicated power is the theoretical power, gained by working out the PLANn formula, effective power is, as it says, actual power at the sharp end. The difference is losses within the engine.
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jimmys
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Re: IP and MEP - whats the difference

Postby jimmys » Sat Feb 18, 2012 8:24 am

The Indicated Mean Effective Pressure(IMEP) is derived by measuring the area of an indicator card and dividing it by its length. This is also known as the Mean Indicated Pressure (MIP). It is P in the PLAN formula.
MEP, I dont know what it means maybe Member of European Parliament. This is an old trick question. If its indicator cards always append by "indicated". Everybody gets mixed up with it.


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