- #1
Jason Louison
- 70
- 6
Hello Physics Forum Community! It sure has been a while! :) I have been hard at work on my goal; to create a spreadsheet that simulates the Internal Combustion Engine (Spark Ignition). I can't take all the credit for having come this far, so there will be links to a few sources below that I have used in my research. Here are some progress photos!
Sources:
“Home - Walter Scott, Jr. College of Engineering.” Home - Walter Scott, Jr. College of Engineering, www.engr.colostate.edu/~allan/thermo/page8/page8.html.
https://2k9meduettaxila.files.wordpress.com/2012/09/internal-combustion-engines-fundamentals-heywood.pdf
I have created a simulation method of my own for the mass of air entering and exiting the cylinder, but it is very simple. That being said, it probably has a lot of error associated with it. I have come to physics forums to see if there was a better alternative or suggestions of how I could improve the model.
The model is as follows: For any IC (Internal Combustion) SI (Spark Ignition) engine, there is an intake and exhaust valve opening and closing point, usually denoted in degrees BTDC, ABDC, ATDC, BBDC.
If we calculate the mass of air in the cylinder, for example, at tivo and tivc ,take the engine speed (rpm) and convert those values to time, we can derive an equation for mass flow rate with the linear slope formula:
dm/dt=(m2—m1)/(tivc—tivo)
Where m2 is the total cylinder mass, (fuel and air), m1 is the residual mass, tivc is the time at closing of intake valve, and tivo is the time at the opening of the intake valve. For the exhaust mass flow rate, just switch m1 and m2 and turn tivo and tivc into tevo and tevc
“Home - Walter Scott, Jr. College of Engineering.” Home - Walter Scott, Jr. College of Engineering, www.engr.colostate.edu/~allan/thermo/page8/page8.html.
https://2k9meduettaxila.files.wordpress.com/2012/09/internal-combustion-engines-fundamentals-heywood.pdf
I have created a simulation method of my own for the mass of air entering and exiting the cylinder, but it is very simple. That being said, it probably has a lot of error associated with it. I have come to physics forums to see if there was a better alternative or suggestions of how I could improve the model.
The model is as follows: For any IC (Internal Combustion) SI (Spark Ignition) engine, there is an intake and exhaust valve opening and closing point, usually denoted in degrees BTDC, ABDC, ATDC, BBDC.
If we calculate the mass of air in the cylinder, for example, at tivo and tivc ,take the engine speed (rpm) and convert those values to time, we can derive an equation for mass flow rate with the linear slope formula:
dm/dt=(m2—m1)/(tivc—tivo)
Where m2 is the total cylinder mass, (fuel and air), m1 is the residual mass, tivc is the time at closing of intake valve, and tivo is the time at the opening of the intake valve. For the exhaust mass flow rate, just switch m1 and m2 and turn tivo and tivc into tevo and tevc