jt2ma71
25-10-2004, 02:27 AM
I have a book that was given by a good friend. I'm on the chapter about water injection and was wondering how accurate this is, especially the last couple sentences...
"When we inject water it can provide a number of benefits, depending on where our turbocharged engine has a deficiency. So far we have only mentioned that water helps when we are low on fuel octane. The manner in which it helps here is that during combustion the water is converted to steam. That conversion pulls heat out of the combustion process, slowing the rate of pressure rise in the combustion chamber. Additionally, these steam particles get in between fuel and oxygen molecules which again slows combustion and pressure rise rate. While this is going on the piston continues moving to TDC squeezing the gases tighter and tighter, but with less heat in the chamber and a slower pressure rise things don?t get out of hand to induce detonation. Then as the piston slowly begins to descend a controlled burn continues, but the combustion flame now has to duck around steam molecules plus an increasing number of exhaust gas molecules to get to fuel and oxygen molecules. As such, peak cylinder pressure will be reached at about 15 deg. after TDC. Any later than 18-20 degrees we lose power; earlier than 12-14 degrees we could precipitate detonation."
--Ron
"When we inject water it can provide a number of benefits, depending on where our turbocharged engine has a deficiency. So far we have only mentioned that water helps when we are low on fuel octane. The manner in which it helps here is that during combustion the water is converted to steam. That conversion pulls heat out of the combustion process, slowing the rate of pressure rise in the combustion chamber. Additionally, these steam particles get in between fuel and oxygen molecules which again slows combustion and pressure rise rate. While this is going on the piston continues moving to TDC squeezing the gases tighter and tighter, but with less heat in the chamber and a slower pressure rise things don?t get out of hand to induce detonation. Then as the piston slowly begins to descend a controlled burn continues, but the combustion flame now has to duck around steam molecules plus an increasing number of exhaust gas molecules to get to fuel and oxygen molecules. As such, peak cylinder pressure will be reached at about 15 deg. after TDC. Any later than 18-20 degrees we lose power; earlier than 12-14 degrees we could precipitate detonation."
--Ron