Thanks for all the input everyone.
I am now convinced that I've got the torque numbers right.
They add up, and they make sense in relation to what the actual machine can do.
However, I'm still mis-calculating the power requirement somehow.
Using the same formula as Robin, I'm trying to...
Thank you everybody.
I think I shall take a step back and start again at first principles.
I'll try your suggestions and be very careful with any assumptions I'm making.
Thanks for the help.
Thanks for the help BobM3 and dgallup.
I'm going to have another look at what I'm doing to make sure I've got all of my units in the right place and such.
At first glance it seems OK, but something must be wrong.
I just can't see how 790 kW can be right for a 33 ton truck.
I'm trying to work out the power required at the wheel. I'm planning to try to specify my powertrain from the power and torque necessary at the wheels.
I'm actually calculating forces to move the truck from drag, rolling resistance, inertia and grade. I'm trying to calculate the power from that...
I'm trying out some ideas for improving drive train efficiencies. For this, I'm trying to model the power necessary at the wheels of a truck.
To validate this, I've entered the specs of a real truck, and the Heavy-vehicle version of the Urban Dynamometer Drive cycle.
My calculation is that the...
