Thank you for your support.
Bpval wrote:“Perhaps Echo-Motor3 next year will be more successful. Congratulations on your approach
Too bad for the results more than mixed ... and the cap !!! ??? "
In order to start the tests, while being certain of having steam production, we left the engine running, and waited to visually observe this creation.
Then we found that the vacuum created by the engine in the system was not enough to draw the steam. The latter therefore had no preferred direction, and went out where it could, and therefore by the air supply from the system. Hence the installation of the plug.
Remundo wrote:“In addition, I think that the injection of water, to express its full potential, requires more elaborate engines, in particular with variable valve timing and variable compression ratio, combined with precise control of steam production. The optimization window is probably very small: not enough water: no effect, too much water: flooding the engine, degraded combustion ... ”
The theory of the optimal zone of the production of vapor, is indeed a hypothesis which had crossed our mind, during the exploitation of the results. This would explain why there is a point drop in consumption, however small, which does not affect all plans.
In the same way that the optimal mixture is 1 gram of fuel for 15 grams of air, one might think that there is an ideal amount of water vapor. Quantity that it is not possible to control (except during sizing) with such a system, devoid of electronic management. This is the kind of theory to which we alluded in the conclusion of the technical part of the final dossier.
Christophe wrote:"What about pollution ?? "
As specified in the report, it was planned to carry out pollution tests, using a gas analysis bay. Unfortunately, due to lack of time and availability of equipment, we did not have access to it. Hence the regrettable absence of this test.
Christophe wrote:"How long did your tests last (effect of descaling by water?"
Concretely, the tests were carried out during the school holidays, on April 14 and 15, in the afternoon. The descaling test was carried out in the afternoon of Tuesday, which means that the engine had already run on Monday, and part of the afternoon of Tuesday. We therefore roughly estimate the operation of the engine with the system at 2 hours.
Remundo wrote:"Their opacimeter was defective"
No, we have never reported any “opacimeter” malfunction.
Christophe wrote:"Make tests at load and high torque compared to the maximum power / torque ... but we never exceeded 65% load apparently. "
Our engine showing certain signs of fragility, our supervisors advised us not to seek it unduly. An engine failure would have been the worst case (not enough time to start looking for a spare engine), so we preferred not to take a risk and play the card of caution.
Christophe wrote:In fact your tests are exactly the same as those made on a tractor test bench: no dynamic test (measurement when the torque varies) was carried out. So without a "peak" of power / combustion temperature, the effect is reduced ... or even zero.
Maybe the bench is not capable of it ... but in this case a tractor bench does as well. Too bad ... I understood that dynamic tests would have been possible ... "
As you will probably have understood, we were pressed for time and close to being unable to carry out the tests. Thus, we favored the study at constant regime, the implementation of which was altogether easier. With hindsight, and especially now that we know much more precisely how a test bench works, it is true that we would do otherwise, by imposing a precise cycle, varying most of the parameters of the engine, so as to approach the behavior of the engine in road use.
Christophe wrote:"Pkoi phase 1 and 2 were not done at 70 and 80 Nm ???
It was not planned at the outset to make the part called "optimization" in the summary table. This followed a simple observation: steam was not produced for the configurations initially proposed (at 50 Nm, and for 1500 and 2000 revolutions per minute).
Christophe wrote:In terms of load curves: how do you explain the "saw teeth" of certain tests? As well as some changes of "bearings"? All the same, these are not negligible changes in load ... "
Regarding the "significant" load changes, we do not agree. By relying on the scale, we realize that there is a "zoom" effect, and that ultimately, the saw teeth, or the bearings, are in fact only variations of 1% at most of the engine stress. Amount small enough to be justified by the inaccuracies due to the bench.
Christophe wrote:"Finally, only one series of tests is" significant "in my opinion: the test at 2500 tr and 50 Nm because it is the only one which can compare with the origin under the same load conditions although it does not is not loaded enough but hey ... "
Not having observed a cleaning effect, due to the lack of longevity of the test, we compared phase 4 to a complement, even a substitute, of phase 1, serving as a comparative basis. Phase 5 was compared to these results.
Christophe wrote:"I am convinced that if the original 80 Nm test had been done, it would have shown an even greater relative gain ..."
First of all, remember that we are only student-engineers, striving to keep the most neutral vision possible on the issue. Without wanting to be offended, wouldn't you wait too long for a “scientific” study to arrive saying “yes! there is indeed a decrease in consumption of 30%, and a decrease of 80% in pollution. "?
Finally, know that it is with great bitterness that we see today that the study that we have carried out has not been as thorough as we would have liked.
PS: Oooops! Sorry for this long post ...