Positive-displacement screen
Hydraulic pump
Inputs
Geometric positive-displacement volume per shaft revolution.
Declared pump input speed in the steady operating point.
Pressure rise across the pump at the stated point, not a component pressure-rating check.
User-entered percentage used only to screen actual outlet flow.
User-entered percentage used only to screen shaft input from hydraulic output.
Results
Ideal outlet flow
37.5
Declared-efficiency outlet flow
34.5
Hydraulic output power
10.35
Declared-efficiency shaft input power
12.321
Theoretical pressure-displacement input torque
71.62
Qideal = Vd·n; Qdeclared = ηvQideal; Phyd = ΔpQ/600; Pin = Phyd/ηo; Ttheory = ΔpVd/(2π)
A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.
Nearby: Hydrostatic pressure · Flow continuity · Pipe mean velocity · Bernoulli equation
Method
Formula, when it applies, and when it does not
Calculate ideal and actual outlet flow, hydraulic power, shaft-input power, and theoretical input torque from a pump displacement, speed, pressure, and efficiencies.
Qideal = Vd·n; Qdeclared = ηvQideal; Phyd = ΔpQ/600; Pin = Phyd/ηo; Ttheory = ΔpVd/(2π)
When
- Positive displacement
- Steady state
- User-entered efficiencies
- No relief/line losses
Don’t
- This is a steady positive-displacement pump screen using user-entered displacement, pressure, and efficiencies. It does not select a pump, motor, drive, relief setting, fluid, line, reservoir, cooling method, or rating; model cavitation, leakage beyond the declared efficiency, pressure ripple, heat balance, transient load, or component/system safety; or approve a fluid-power system.