2.2. Calculating Required Power Using Performance Charts

Try these first

1. 1.

   What happens to air density as altitude increases?

   Hint

   Think about the atmosphere and how it changes with height.

2. 2.

   What is a turbocharger?

   Hint

   Consider what happens to air as it gets compressed.

3. 3.

   How does altitude affect internal combustion engine performance?

   • It increases the horsepower output
   • It has no effect at all
   • It decreases the horsepower output
   • It only affects the fuel quality

   Hint

   Think about what happens to air density at higher altitudes.

4. 4.

   True or False: A turbocharger is unnecessary for engines operating at sea level.

   • True
   • False

   Hint

   Consider why we might need such devices.

5. 5.

   A bulldozer is working at 2000 meters elevation with a gross weight of 9000 kg. If the estimated grade resistance is 10% and the rolling resistance is 5%, calculate the total resistance and show how to derive the required power from the performance chart.

   Hint

   Use the chart to find where the lines intersect based on your total resistance.

6. 6.

   A certain machine's performance at sea level shows a rimpull of 1000 kg, while at 3000 m altitude, it drops to 700 kg. If the vehicle's resistance is calculated at 12%, how can you adjust your calculations for efficiency loss?

   Hint

   Reflect on the decrease in power output and connect it to altitude effects.