Need help asap - Thermal Efficiency of a Two Stroke Engine
11-04-2002 | 05:10 PM
#1
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From: Ireland
Need help asap - Thermal Efficiency of a Two Stroke Engine
Hi guys,
I would just like to find out what the thermal efficiency, TE, of a typical model engine is. (TE = ratio of heat converted into work compared to heat recieved). I know that in a 4-stroke gasoline engine the TE is approx 30%.
i.e. Normal, low compression car -> .26
Racing Car -> .34
What kind of number should I expect from a model engine. This is really important for me as i need to now this as soon as possible for my professor. Are they more or less efficient than a typical two stroke engine??
Thanks,
UCC
I would just like to find out what the thermal efficiency, TE, of a typical model engine is. (TE = ratio of heat converted into work compared to heat recieved). I know that in a 4-stroke gasoline engine the TE is approx 30%.
i.e. Normal, low compression car -> .26
Racing Car -> .34
What kind of number should I expect from a model engine. This is really important for me as i need to now this as soon as possible for my professor. Are they more or less efficient than a typical two stroke engine??
Thanks,
UCC
11-04-2002 | 07:49 PM
#2
Senior Member
Need help asap - Thermal Efficiency of a Two Stroke Engine
Ha. Good luck. Try this: Typical fuel consumption in oz/min= displacement in 1*cid. So, 1.0 cubic inches = 1 oz/min. AND, typical power in Hp = 2*cid. So, 1.0 cubic inch = 2 hp.
So we have 2 Hp at 1 oz/min methanol. This is not at peak operating condition, rather, at normal "flight load" conditions. You'll have to calculate the heat value of methanol.
So we have 2 Hp at 1 oz/min methanol. This is not at peak operating condition, rather, at normal "flight load" conditions. You'll have to calculate the heat value of methanol.
