pressure, temperatur inside ic engine......

muthu2007

1. what will be the temperature produced during the combustion
process?? (NEGLECTING THE COOLING EFFECT PRODUCED by the cooling system)

2. The temperature of the exhaust gas at the exhaust
"port" ??(CONSIDERING AND WITHOUT CONSIDERING THE COOLING EFFECT PRODUCED by the cooling system)

3. In case of a turbo-charger what will be pressure and temperature
of the fresh air which will be injected to the engine??......for any capacity of turbocharger.....

brewnog

Depends entirely on the engine design, type, and operating conditions. Without these, the answers are:
1 - very hot
2 - hot
3 - between 0 and 5 bars, between about -10 and 200 degrees Celsius.

ank_gl

1.about 800-1200 degree C
2.about 80-120C
3.as brewnog said

muthu2007

Depends entirely on the engine design, type, and operating conditions. Without these, the answers are:
1 - very hot
2 - hot
3 - between 0 and 5 bars, between about -10 and 200 degrees Celsius.
__________________

thankx for u r replys..........brewnog as u said that it entirely depends on the design,type and operating conditions....plz...consider a normal ic engine in mahindra scorpio ...it has
cc:2609cc
max power:115bhp(85 kw)@3800rpm
max.torque:28.3kgm @ 1700-2200 rpm...


so for the above case wt will be the answers??

thankx in advance

brewnog

I take it that a Mahindra Scorpio is a car? Petrol or Diesel? Turbocharged or naturally aspirated? Compression ratio? Under what operating conditions? Speed? Torque? Ambient temperature? Altitude? Timing?
Combustion temperatures may be 1500 Celsius. Exhaust port temperatures may be up to 600 Celsius. However, at idle, these could be much lower.

brewnog

Exhaust port temperatures on load are much higher than this.

ank_gl

yea scorpio is a SUV brewnog
muthu, not everyone knows about mahindra, and there is more to be said about the specs of the engine

kevindeschamp

muthu2007,
Temperature produced during the combustion process with a compression ratio of 11 to 1 the ideal otto cycle temperature would be around 4500 degrees C and compression ratio of 5 to 1 the ideal otto cycle temperature would be around 3500 degrees C.

source: Gordon P. Blair, "Design and Simulation of Four Stroke Engines"

Kevin

kevindeschamp

muthu2007

2. The temperature of the exhaust gas at the exhaust
"port" ??(CONSIDERING AND WITHOUT CONSIDERING THE COOLING EFFECT PRODUCED by the cooling system)

I am giong to say the same temperature of the cylinder minus a few degrees.

Kevin

brewnog

Exhaust port temperatures are MUCH cooler than peak cylinder temperatures, and are much more like average cylinder temperatures. Think about how you'd make an exhaust valve live at 4500 degrees C!

Depending on the engine type, and ambient and operating conditions, exhaust port temperatures very rarely get above 750 degrees C.

kevindeschamp

[QUOTE=brewnog;1490342]Exhaust port temperatures are MUCH cooler than peak cylinder temperatures, and are much more like average cylinder temperatures. Think about how you'd make an exhaust valve live at 4500 degrees C!

4500 degrees C is ideal otto cycle temperature.
If your combustion chamber temperature is 1000 degrees C right when exhaust opens than the throat (area between cylinder and exhaust pipe) temperature will be on 800 degrees if the gas is all exhaust gas. If its air and exhaust it will be about 780 degrees. The exhaust pipe temperature will be 1000 degrees after the throat.

Kevin

engware

Hi there:

Here are two URLs that can help you with calculations related to your question.

Online calculators for simple power cycles (Carnot, Brayton, Otto and Diesel)
http://members.aol.com/engware/calc3.htm

Spreadsheet dealing with combustion calculations
http://engware.i-dentity.com/pf/combustion.xls

Here is a plot regading combustion products flame temperature for ideal and complete stoichiometric combustion conditions.



I do hope that the provided URLs will cover some of your concerns when doing engineering calculations related to the technical performance of simple power cycles and combustion.

Thanks,

Gordan