If a compressor has a volumetric efficiency of 70% and the theoretical mass is 8.65 kg/min, what is the actual mass moved?

To determine the actual mass moved by the compressor, we can use the concept of volumetric efficiency, which is the ratio of the actual volume of air (or gas) delivered to the volume that would be delivered if the compressor were operating at its theoretical efficiency.

Given that the volumetric efficiency of the compressor is 70%, this means that the compressor can only effectively move 70% of the theoretical mass flow. The theoretical mass flow is given as 8.65 kg/min.

To find the actual mass flow, we multiply the theoretical mass flow by the volumetric efficiency (expressed as a decimal):

Actual mass flow = Theoretical mass flow × Volumetric efficiency

Substituting in the values:

Actual mass flow = 8.65 kg/min × 0.70

Calculating this gives:

Actual mass flow = 6.055 kg/min

Rounding this number, we get approximately 6.06 kg/min, which corresponds to the correct answer. This demonstrates that the actual mass flow is lower than the theoretical mass due to the limitations of the compressor, represented by its volumetric efficiency. Thus, the calculation directly leads to the conclusion that the actual mass moved is 6.06 kg/min.