Use when you must size the bootstrap air-cycle cooling pack thermodynamics for the ECS cooling load: compute the compressor exit state from the pack-inlet bleed condition, pressure ratio and isentropic efficiency, cool the discharge through the ram-air heat exchanger at a given effectiveness, expand through the cooling turbine to cabin pressure, close the two-wheel ACM shaft balance, and turn the turbine exit temperature into delivered cooling against the cabin design temperature.
