A hydraulic air compressor entrains air in descending water and separates it at depth, where water-column head can maintain compressed air. This calculator converts only an entered effective head difference into ideal hydrostatic gauge pressure.
Water-jet Air Compressor Interactive Calculator
Enter total vertical drop and the portion assigned to tail recovery. The nonnegative difference is treated as ideal pressure head and converted to psi, kPa and bar—not air delivery, efficiency or real system pressure.
Equation Used
- Total drop and tail-recovery height are entered independently.
- Negative effective head is clipped to zero.
- Water is represented by the approximate factor 0.433 psi per foot.
- Outputs are ideal gauge-pressure conversions only.
- Air flow, entrainment, compression ratio, losses, temperature, separator dynamics, piping and structural limits are omitted.
Hydraulic Air Compressor Pressure Head
An U.S. Department of Energy report describes a hydraulic air compressor as entraining air in falling water, separating it at depth and compressing it to the hydrostatic head of the air-water column. A detailed DOE performance study shows that real systems require flow and loss analysis beyond this ideal conversion.
What This Calculator Represents
The tool subtracts an entered recovery height from an entered drop, clips the difference at zero, and converts the resulting ideal water head among pressure units.
Ideal Head-to-Pressure Calculation
p≈0.433h psi
p_kPa=6.894757p_psi
p_bar=p_kPa/100
This is gauge-pressure arithmetic, not compressor performance.
Worked Conversion
For 100 ft total drop and 90 ft recovery, effective head is 10 ft, ideal gauge pressure is about 4.33 psi, 29.9 kPa or 0.299 bar.
Assumptions and Limits
- Calculated: nonnegative entered head difference and pressure-unit conversions.
- Illustrated: downcomer, entrained bubbles, separator and recovery level.
- Not calculated: air flow, efficiency, compression thermodynamics, friction, gas fraction, separator dynamics or equipment design.
Frequently Asked Questions
Does this predict air flow?
No.
Is pressure absolute?
No; it is an ideal gauge-pressure conversion.
Is 0.433 exact?
No; it is an approximate freshwater factor.
Are pipe losses included?
No.
Can tail recovery exceed drop?
The tool clips effective head to zero.
Can this size a trompe?
No.
References
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