Ejectors (or jet pumps) are simple yet critical devices used in chemical plants, HVAC, and oil refineries to create vacuum or move fluids using a high-pressure motive fluid. Designing one involves complex gas dynamics—but many engineers rely on Excel spreadsheets (.XLS) to speed up iterative calculations.
For the "fixed" keyword to hold true, the spreadsheet must include a validation sheet that compares calculated ω against experimental data from 50 known ejector tests. If the user’s inputs produce an ω outside the 95% confidence band, the cell highlights in red with a hard-coded warning: "Check motive pressure or backpressure." ejector design calculation xls fixed
Calculate the velocity of the motive fluid as it exits the nozzle. Mastering Ejector Design: How to Use & Fix
A traditional fixed ejector consists of four primary sections: the primary nozzle, suction chamber, mixing chamber, and diffuser. In a "fixed" design, the throat areas and section lengths are set during manufacturing, meaning the ejector's performance is strictly a function of its boundary conditions (inlet pressures and temperatures). Key Design Parameters Entrainment Ratio Validation Table For the "fixed" keyword
where Q_s is the secondary fluid or gas flow rate, ρ_m is the mixture density, and v_m is the mixture velocity.