What about thermo electric generation using peltier effect ceramics? Not sure how much power would be available but the concept is heating doped ceramics creates a current. Might be worth a look.
My experience on similar systems (Mini Cooper S) has shown that the bypass (operated on purely manifold vacuum with no active control) is continually variable so even at part load there is still some positive pressure effect from the S/C. On the Siemens system used on Mini this was compensated...
murpia,
The combustion rate I referred to was the crank angle duration between 5% and 95% mass fraction burnt (measured using an incylinder pressure transducer). Essentially this crank angle duration stays more or less constant with a change in engine speed (hence speeds up or slows down in...
I've measured combustion on a 2.0l DI diesel (fitted with an electroniuc Bosch distributer pump) and within it's preset constraints (max engine speed =4500rpm) the combustion rate scaled as a virtually linear function of engine speed if you removed some of the obvious conflicting factors (e.g...
Facinating debate, it's worth the extra legislation just to get good threads like this:)
Once we've got to the stage that the catalyst has to be working <1 min after start at normal ambient temps (LEV, LEVII, EU4) going any further is frankly rediculus. As it is catalyst heating for EU4 costs...
There's no doubt the knock sensors will pick up things like valve train noise, piston slap (almost anything high frequency depending on the calibration). On a recent hot trip I had an engine let go at WOT (due to a miss build of the oil pick up) and subsequently looking at the recording there...
Normally EGR on gasoline engines is introduced after the throttle at part load and thus is in addition to the air charge and thus doesn't displace any air. On an unthrottled diesel engine however it does displace fresh air ( in fact this is how it is usually controlled). It works as GregLocock...
The addition of water to the inlet shouldn't effect the lambda meter reading as it essentially measures free O2 not AFR (the lambda:AFR relationship changes depending on composition of the AFR components). As H2O is inert and provides no 'new' 02 to the system the lambda (rather than AFR)...
This is normally due to poor lambda biasing. The closed loop fuelling system is biased slightly rich to ensure that is no NOx breakthrough during closed loop operation. This is because the catalyst efficiency is much less sensitive on the rich side (HC & CO conversion) than on the lean side (NOx...
Swirl or turd I like it:)
Swirl is important in engines (gasoline and diesel) as it (all else being equal) increases heat release rate and gets closer to constant volume combustion and thus (theoretically at least) increases thermal efficiency. However, it also increases heat transfer from the...
Bayislandsdiver,
The chemistry and physics of NOx formation in internal combustion engines is well understood to be a rate controlled reaction (ie it never gets to equilibrium conditions) variable as a function of temperature and component availability (i.e. N, N2, O & O2). Although the...
Is that the jingle of spurs I hear.....
AFR is very important (particularly in a racing application)as the max power occurs rich of stoichiometric (lambda 0.9) and not at a fixed exhaust temperature (which is very much a factor of spark timing).
Hi Andy,
My point is that you can scale the linearisation curve of the switching sensor (it is done in ME7 as the whole closed loop fuelling control including rear trim is done in the lambda domain). The problem is, because of the relatively flat response either side of the switch point the...
Andy,
There is a linearisation curve for switching sensors (see Bosch Automotive Handbook) which does describe lambda as a function of voltage output. It's how post catalyst sensors are used as fuelling trim. In terms of the effect of temperature on the shape of the curve I'm pretty sure that...
