Trucks entering and leaving a mine

[Customer]

I’m trying to model a truck driving through the mine entrance down the ramp to a loader and then up again. The trucks will be above ground, outside the mine, for some time. What would be the best way to model this scenario?

[Martin Griffith]

You can model this situation in a Heat Simulation using an Activity Track with the Delay Restart option.

Set up your Activity Track. Then calculate the amount of time that the truck will be outside the mine and enter the value in the field for "Delay restart". Doing this, Ventsim will discount the amount of heat generated by the truck corresponding to the time the truck is out of the mine. 

However, using the Delay Restart means that Ventsim will need to know the amount of time it takes to travel along the path. That means that for the Delay Restart to have an effect, you need to also:

• specify a vehicle type to set the speed of the truck, and
• specify whether the track is bi-directional.

A vehicle travelling on a track specified as bi-directional will start at one end of the track, travel the length of the track, turn around and travel the length of the track again and then finish where it started. So specifying the track as bi-directional will affect the relative portion of time that the truck spends outside of the mine.

The direction of the track will only be important for a Dynamic Simulation. For a steady-state Heat Simulation, it shouldn’t make a difference at which end the track starts.