To all,
My primary concern is low vehicle load. For example when you stop accelerating and see a red light in front. All these time until you accelerate from stop light you are burning up gas. Please do not bring hybrid car into this discussion. YOU know it is unfair.
If we can purge the air out when cylinder is at 500-800 rpm, as I posted in previous notes, it makes major difference in city driving economy. Are you guys with me on this? Suppose you spend one hour driving in the city, it is fair to say 1/3 of time your engine is idle, either you are braking or just sitting there for the traffic. Let me see. Your average city speed is say 20 mph.
Thus, you moved 20 miles in one hour. As we agreed that every two minutes of idle the car could have moved 1 mile. The total idling time is 20 minute. And thus we could have moved 10 more miles(actually it is a geometric series, I ignore the extra).
Now, this is really important, Instead of getting your 20 miles. With Chen engine you get 25 mile (because we save only half of the gas).
If we simply have just a small compressor that cleans up the residual air during idle, The compressor only needs to purge engine turning only at 500 rpm (and 250 times a min we need to purge). The exhaust air is very low pressure, as the engine just idle, thus low gas volume. Better yet, you need only inject the air at top dead center, thus 1/10 of the volume. How little gas at 3 ATM is needed to do the job? very small. and power is even less.
As most cars are increasingly turbo charged. As soon a turbo reach operation, the air is supplied by the turbo, that is around 2000 rpm. You let turbo powered compressor do the job for you from 2000 upwards. But Turbo has already cleared all residual gas with scavenging action, thus, it is really redundant.
Bottom line. Do not think that you need purge the exhaust at 6000 rpm. at full load at 1 ATM . You only need to purge out waste gas at idle or at slow cruise. Of course, when I add the gas saving at cruise, say 1400 rpm, the gas saving is on top of that 25 mpg. You rarely do this. In any case, I expect 25% improvement in gas economy in city driving with very minimal effort to use compressor.
I think this very general discussion should be sufficient. We can argue over whether idle time is 1/3 or idle time is 1/4 and cruise time 1/2. I say, give my your manifold vacuum record, I can tell you how much gas you can save with Chen Engine.
Chengine
I do not think it is proper for me to go into detail design in this forum. We are discussing whether certain technology is possible. If you insist on bashing me on certain point my email is
georgeckchen@aol.com and I will throw away flaming e-mails.