willem2 said:
It seems you mean this locomotive?
https://en.wikipedia.org/wiki/EuroSprinter#ES_64_F
The Davis Coefficients seem to be for only the locomotive. A = 1070 seems ok, 1070 N rolling resistance with a normal force of 850kN is a drag coefficent of 0.00125. I can't seem to find any realistic values for B. C is from the drag equation with a Cd of 1.0. and a frontal area of 12.9 m^2. This drag coefficient seems a bit high for a single locomotive, but is likely 2-3 times too low for a long train. The top speed is mainly determined by the value of C.
If you double A, or B, v changes very little. (I typed 1070v + 28.6v^2 + 7.4 v^3 = 6400000 in wolfram alpha)
To get down to a maximum speed of 140 km/hr = 39 m/s you still need to take C = 100. I think the maximum speed of this train comes from safety considerations. 140 km/hr is a common maximum speed on railways in europe. The power is likely needed to accelarate fast enough when pulling a long train or pulling up an incline. According to the wikipedia article the ES64F is used for freight trains.
Hi, thanks for your reply!
You are almost right, the locomotive I am talking about is the ES64F4 or also called the BR189.(But they probably share the same specs)
The coefficients are indeed only for the locomotive, as i will calculate the drag for each locomotive seperatly.
A C of 100 does indeed result in ~39 m/s, but I still am having the idea, it is not behaving as it should as i think the resistance is rising too rapidly(tell me if i am wrong)
So could you maybe tell me what I have to do to make it correct, or why the maximum speed i calculated is more then 300km/h?
In train simulator 2017, MSTS, and youtube videos, the train doesn't seem to go faster then 140, so i seem to be doing something wrong somewhere.
From your post, you seem to be atleast trying to explain what is happening, so could you maybe tell a bit more?
A C of 100 seems wrong to me, and it also seems that fcalc has a reason for using a C of 7.4.
Could you explain a bit more?Thanks!
Edit:
I ahve to correct something, I read someone saying that the ES64F4/BR189 can indeed go faster, 230km/h according to that single person(unsure if true) But i also saw a this train:
https://nl.wikipedia.org/wiki/ÖBB_1216 Which should be able to reach 230km/h according to the site, and it has specs very close to the ES64F4/BR189, and i even saw a video where they got it to 350km/h!
So it is indeed possible, but is it realistic? And why is it not simulated in simulators? Could you maybe talk a bit more about that if you know more?
Thanks ;)