Ejector Calculator

This tool provides rapid, first-pass calculations of ejector performance from basic inputs: motive and suction pressures, operating temperatures, geometry (nozzle and throat areas), and gas properties. It outputs key metrics such as entrainment ratio, discharge pressure, and an approximate power-related figure of merit. It is intended for mechanical engineers, HVAC and refrigeration designers, and researchers performing concept screening, parameter studies, or teaching demonstrations.
Conceptually, the tool applies isentropic relations for the motive jet, ideal gas density from P and T, and mass- and energy-balance considerations to estimate how much secondary fluid is drawn into the mixing region. It uses a simplified mixing model to relate the nozzle flow and suction flow to the downstream condition. Results are suitable for quick comparisons across configurations.
Unique value rests in a transparent, physics-based methodology with clearly stated assumptions and unit-consistent inputs. It supports standard SI units, a consistent set of gas properties, and edge-case validation, enabling engineers to run multiple scenarios in a short time. Use cases include refrigerant ejectors, vacuum-boosting devices, process-heat transfer systems, and educational demonstrations of ejector thermodynamics.
Core features include input validation, automatic unit handling, calculation of beta (entrainment ratio), discharge conditions, and a concise summary of results. The tool emphasizes reproducibility and quick sensitivity analyses without resorting to CFD.