Christophe, Riaz, Remundo, Lietseu, Elec, Gregconstruct… about the TGV
As you know, the consumption to overcome aerodynamic drag * varies with the square of the speed. In other words, a “TGV 200 km / h” consumes 2,56 x less ** of fuel than a “TGV 320 km / h”.
* aerodynamic drag is commonly called " parasitic trail
** (320.200) p2 = 2,56
In reality, the economy is further improved by the considerable reduction in the mass of the motors: the power to overcome parasitic drag is a function of the cube of speed. This gives us an installed power for a “TGV 200 km / h” 4,1 x less *** than the power installed in a “TGV 320 km / h”. Clearly the engines are 4 x less large!
*** (320.200) p3 = 4,1
We must add to the " parasitic drag power
"(Ptp) the power necessary to overcome the rolling forces or" rolling drag
»(Ptr). For airplanes, the rolling drag is replaced by the " induced drag
»By the lift of the wing (Pti).
But that's not all, we must also take into account the mechanical efficiency of the installation (Rm).
This gives us with Pm = power supplied by the motor:
Pm.Rm = Ptp + Ptr for land vehicles and Ptp + Pti for airplanes
It is important to know that Ptr and Pti are negligible compared to Ptp for high speeds (speeds greater than 160 km / h approximately).
… And we can conclude, as the saying goes very well Riaz
. " speed, here is the enemy!
"*, And his prognosis for" low speed green TGV "(TGVBV?) Seems to me, to the chagrin of the" hurry ", frankly realistic!
* The slogan of MATHIS automobiles
was " weight, that's the enemy!
", The circle is complete !
Let's go back to the consumption of the TGV, I'm in the middle of it but it's progressing… At this stage, I am concentrating on the formatting of information. A good part consists in describing the calculation method (as for this calculation, it is a group work of some members of the association "interaction").
See you soon and above all thank you for your encouragement
PS: excuse me for the slightly harsh teacher side but I would like to limit the risk of non-comprehension for a possible uninitiated reader!
PS: see also the document "quality of other means of transport" in the aero part of the site http://www.cocyane.com
, this document will later be the subject of a fun and much more complete comic
PS: Christophe or Riaz: could you tell me, if you find it, the "TGV conso reflection" carried out in the past?