What is the significance of isentropic efficiency in thermodynamics and how is it calculated?

Isentropic efficiency is important in thermodynamics because it measures how well a process can convert energy without any heat loss. It is calculated by comparing the actual work output of a system to the maximum work output that could be achieved in an ideal, reversible process. The formula for isentropic efficiency is: (actual work output / ideal work output) 100.