Right, while I figure that with a constant 27.8 g/second, inlet pressure will fall from some 2.1 to 1.6 Bar absolute between
10.5 and 15.0 kRpm, but I find little reason to rev that far as friction-losses goes with the square of the speed?
It depends on what the gear ratios are, and where the rpms drop after a shift.xpensive wrote:Right, while I figure that with a constant 27.8 g/second, inlet pressure will fall from some 2.1 to 1.6 Bar absolute between
10.5 and 15.0 kRpm, but I find little reason to rev that far as friction-losses goes with the square of the speed?
I don´t think so.xpensive wrote:Which brings us to this, does this mean that the energy stored by MGU-H can only be used to drive the compressor turbine?
5.2.8 The MGUH may only recover energy from or give back energy to the car via its mechanical link
to the exhaust turbine of a pressure charging system. This mechanical link must be of fixed
speed ratio to the exhaust turbine and may be clutched.
But they have also a max fuel allocation of 100kg per racePABLOEING wrote:¿the new engines are a 100kg/ hour?.....nowa rece is about 1H30 minutos with 140kgs.....i dont see a big diference
Renault have claimed in their press release that they can get 2MJ+ from the MGU-H per lap.matt21 wrote:I don´t think so.xpensive wrote:Which brings us to this, does this mean that the energy stored by MGU-H can only be used to drive the compressor turbine?
5.2.8 The MGUH may only recover energy from or give back energy to the car via its mechanical link
to the exhaust turbine of a pressure charging system. This mechanical link must be of fixed
speed ratio to the exhaust turbine and may be clutched.
As the MGU-K can harvest 2 MJ but 4MJ can be sent from the ES to it, the difference has to come from the MGU-H.
And you can have an unlimited energy transfer directly from the MGU-H to the MGU-K without going through the ES.
So possibly you can rev higher as needed in order to get more electricity as long it suceeds frictional losses.
http://i.imgur.com/ugZJQzp.png
I have given you the consistent figures from my source. According to that there were race (R) and qualifying (Q) settings. You have to be aware which ones you use. I have consistently used race figures. If you have mixed up figures from different settings you may arrive at different results. So I think my comparison is still accurate.matt21 wrote:X and I had the discussion 50 pages ago.
http://s7.directupload.net/images/120615/n3zs99eq.jpg
I thought BSFC of the RA168E was 0.272 kg/kW*h at it´s best. This would lead to around 500 hp with the 2014 max fuel flow.
That is debatable. It depends of the injection and combustion mode you use. The highest efficiencies you certainly get from spray guided combustion, but it requires you to inject in very short time intervals. At high revs the pressure of the injection system is often not sufficient to achieve the necessary mass flow. So much depends of the development of systems that operate between the 200 bar that were known in the past and the 500 bar that are allowed for F1 2014.matt21 wrote:I think todays fuel will allow compression ratios of around 10:1.
Road car engine like the Porsche 997 Turbo have around 9:1.
Also with higher rpm you reduce the danger of knocking.
You need to use the updated document version from December 2012. It has no 5.2.8. Instead it shows the graph with all the energy transfer rules in the appendix.xpensive wrote:Which brings us to this, does this mean that the energy stored by MGU-H can only be used to drive the compressor turbine?
5.2.8 The MGUH may only recover energy from or give back energy to the car via its mechanical link
to the exhaust turbine of a pressure charging system. This mechanical link must be of fixed
speed ratio to the exhaust turbine and may be clutched.
You forgot to mention that the enthalpy stream that enters the turbine is also likely to decrease. The exhaust gas at lower boost has more velocity but less pressure. As temperature and pressure are thermodynamically linked the MGU-H is probably supplied with exhaust gas at a lower energy state which makes it more difficult to extract electricity. I don't believe that the rev band above 10.500 is beneficial except for gearing purposes. I'm pretty sure that the total efficiency drops at rpm over 10.500. Unfortunately I don't have the know how to calculate it with an engine model, but perhaps Ringo can.wuzak wrote:....But also at higher revs as the boost required goes down, the power to drive the compressor goes down, but the power driving teh turbine doesn't go down as much, so more power is generated by the MGU-H. This may compensate for the increase in friction.xpensive wrote:.... I find little reason to rev that far as friction-losses goes with the square of the speed?
AFAIK the Renault design rotates the MGU-H with the turbine speed without reduction. The rule change about turbo compounding was published in December 2012. Until then it was believed that compounding would be introduced with one year delay in 2015.xpensive wrote:When did this happen and does anyone know what sort of gearing they use between the turbine shaft and MGU-H?
5.2.4 The MGU-H must be solely mechanically linked to the exhaust turbine of a pressure charging system. This mechanical link must be of fixed speed ratio to the exhaust turbine and may be clutched.
The rotational speed of the MGU-H may not exceed 125,000rpm.
2 MJ per lap, that means an average 25 kW over an 80 second lap, is that realistic?wuzak wrote: ...
Renault have claimed in their press release that they can get 2MJ+ from the MGU-H per lap.
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