Ejector Design | Calculation Xls Fixed

) of the fluid flow to dynamically scale aerodynamic efficiencies. 5. Step-by-Step Design Verification Checklist

) does not exceed the "critical discharge pressure." If it does, the shockwave will move back into the throat, and the ejector will stop suctioning (breaking the vacuum). 4. Structuring Your XLS for Accuracy

To create a , structure your workbook into four distinct, color-coded sections. Section 1: Input Data (User-Defined) Define these inputs in column B. Description P_m Motive Fluid Pressure T_m Motive Fluid Temperature m_m Motive Mass Flow Rate P_s Suction Fluid Pressure T_s Suction Fluid Temperature m_s Target Suction Mass Flow Rate P_d Required Discharge Pressure Section 2: Fluid Properties (Lookups or Manual) Molecular Weight ( MWcap M cap W ): g/mol Specific Heat Ratio ( ): Dimensionless (e.g., 1.4 for air, 1.3 for steam) Compressibility Factor ( ): Dimensionless Section 3: Fixed Calculation Formulas ejector design calculation xls fixed

Typically: Dd = Dt × 3 to 6 (use 4.5 as fixed default for initial sizing).

= P_m / P_s Example: 5 / 0.1 = 50

The ejector stops pulling vacuum entirely (breaks operation). Issue B: Discharge Pressure ( Pdcap P sub d ) is Too High

A robust spreadsheet typically includes these sections: ) of the fluid flow to dynamically scale

By ensuring your spreadsheet distinguishes between these modes and correctly handles compressibility and area ratios, you can reliably predict the behavior of these elegant, motiveless machines.

) is a function of the motive pressure, temperature, and nozzle throat diameter. Performance Curves: Description P_m Motive Fluid Pressure T_m Motive Fluid

Expands the high-pressure steam to supersonic velocities, dropping its static pressure below that of the suction fluid.

Em=MWactualMWair⋅TairTactualcap E m equals the square root of the fraction with numerator cap M cap W sub a c t u a l end-sub and denominator cap M cap W sub a i r end-sub end-fraction end-root center dot the square root of the fraction with numerator cap T sub a i r end-sub and denominator cap T sub a c t u a l end-sub end-fraction end-root 4. Step-by-Step Architecture for your XLS Spreadsheet