coefficient of friction
coefficient of friction
(OP)
What is the coefficient of friction for calculate the pull force in a rail car?
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RE: coefficient of friction
RE: coefficient of friction
What exactly are you trying to calculate? The resistance of a rail car to rolling is made up of many things.
RE: coefficient of friction
RE: coefficient of friction
I need to calculate the resisting force for design the counter weight to haul the rail car.
RE: coefficient of friction
I don't understand what you mean by using a counter-weight to haul a car, but if it is what I picture in my mind, then you have a constant force, which means acceleration. Note that most of the terms of the equation have a speed component.
Train Resistance:
TR = 1.3W + 29n + 0.045WV + [0.0024 + 0.00034(Q-1)]AV^2 pounds force where:
TR = Total train resistance in pounds force
W = Total train weight in tons
V = Train speed in miles per hour
A = Frontal area in square feet
Q = Number of cars in the train
n = Number of axles in the train
or TR = 6.4M + 130n + 0.14MS + [0.046 + 0.0065(Q-1)]AmS^2
Newtons where:
TR = Total train resistance in Newtons
M = Total train mass in metric tonnes
S = Train speed in kilometers per hour
Am = Frontal area in square meters
Q = Number of cars in the train
n = Number of axles in the train
RE: coefficient of friction
For those of us who think in terms of rolling resistance, then a steel tire rolling on a steel rail has a coefficient of .001 to .002 according to the blue book, but MintJulep's equation is better.
The implied coefficient there is 6.4/(1000 * 9.81), 0.00065
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: coefficient of friction
Thanks for straightening me out :)
RE: coefficient of friction
RE: coefficient of friction
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.