1. What is Pump Shaft Power?

Definition: Shaft power is the mechanical power required at the pump shaft to deliver the hydraulic power to the fluid.

Purpose: This calculator helps engineers determine the power needed to drive a pump for a specific fluid flow application.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_s \) — Shaft power (Watts)
• \( Q \) — Flow rate (m³/s)
• \( \rho \) — Fluid density (kg/m³)
• \( g \) — Gravitational acceleration (9.81 m/s²)
• \( h \) — Head (m)
• \( \eta \) — Pump efficiency (decimal, 0-1)

Explanation: The formula calculates the power needed to move a fluid at a given rate against a specific head, accounting for pump efficiency.

3. Importance of Shaft Power Calculation

Details: Proper shaft power calculation ensures correct pump selection, motor sizing, and energy efficiency in fluid systems.

4. Using the Calculator

Tips: Enter the flow rate in m³/s, fluid density (default 1000 kg/m³ for water), head in meters, and pump efficiency (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is typical pump efficiency?
A: Centrifugal pumps typically range from 40-85% efficiency (0.4-0.85), with 0.7-0.8 being common for well-designed pumps.

Q2: How do I convert the result to horsepower?
A: Divide Watts by 746 to get horsepower (1 HP = 746 W).

Q3: What if my flow rate is in L/s?
A: Convert to m³/s by dividing by 1000 (1 L/s = 0.001 m³/s).

Q4: What's the difference between shaft power and hydraulic power?
A: Hydraulic power is \( Q \times \rho \times g \times h \). Shaft power includes the efficiency factor (\( P_s = P_{hyd} / \eta \)).

Q5: How does fluid density affect the result?
A: Higher density fluids require more power to pump at the same flow rate and head.