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Miller11
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1) I need to find the output power in kW of an engine when running a mix of 90% Nitromethane
(CH3NO2), and 10% Octane (C8H18), their calorific values are 11.3 MJ/kg and 43.7 MJ/kg respectively.
what i know:
An engine that runs pure 100% octane with 20% excess air produces 100kW, and the volumetric, thermal and mechanical efficiency's remain the same.
I need to find out how much power the same engine using a 10/90 fuel mix would produce.2)Im using this equation:
Power (kW)=Power (kJ/sec)= [calorific value fuel(kJ/kg)] X [molar mass of fuel(kg/mol)] X
[mol/sec]
Im assuming since the volumetric efficeincy will be the same then the [mol/sec] i get for the first engine will be the same as the second fuel mix.
100kW = [(43.7 x 10^3)kJ/kg] X [(114.224)kg/mol] X mol/sec
hence,
mol/sec for both engines = 0.02.
But I am stuck from there and don't know how to continue, as when i try subbing this value into the same equation with the second fuels mix, i get a lower power which it shouldn't be.
Any help would be greatly appreciated.
Cheers Miller11
(CH3NO2), and 10% Octane (C8H18), their calorific values are 11.3 MJ/kg and 43.7 MJ/kg respectively.
what i know:
An engine that runs pure 100% octane with 20% excess air produces 100kW, and the volumetric, thermal and mechanical efficiency's remain the same.
I need to find out how much power the same engine using a 10/90 fuel mix would produce.2)Im using this equation:
Power (kW)=Power (kJ/sec)= [calorific value fuel(kJ/kg)] X [molar mass of fuel(kg/mol)] X
[mol/sec]
Im assuming since the volumetric efficeincy will be the same then the [mol/sec] i get for the first engine will be the same as the second fuel mix.
100kW = [(43.7 x 10^3)kJ/kg] X [(114.224)kg/mol] X mol/sec
hence,
mol/sec for both engines = 0.02.
But I am stuck from there and don't know how to continue, as when i try subbing this value into the same equation with the second fuels mix, i get a lower power which it shouldn't be.
Any help would be greatly appreciated.
Cheers Miller11