Ingap.dev - A Personal Dev Blog

Need a quick power calculation for your fluid system? Whether you're verifying a pump selection or estimating power requirements, our calculator gives you instant results without diving into complex fluid dynamics equations.

When Do You Need This?

You've got a fluid that needs to move from point A to B. Maybe it's water from your basement, oil in an industrial process, or coolant in your system. You need to know how much power it'll take - and you need to know quickly. That's exactly what our calculator is for.

Quick Results with Our Calculator

The Fluid Power Calculator gives you instant results with just a few inputs. No complex equations, no long calculations - just the power numbers you need.

Tell it:

• Height difference (how high you're pumping)
• Flow rate (how much fluid)
• Basic pipe info (length and size)
• Fluid type

Get:

• Theoretical hydraulic power
• Actual power needed (with efficiency and safety factors)

The Science (For Those Who Care)

Here's the complete breakdown of how we calculate your power requirements.

Key Assumptions:

• Pump efficiency (η): 70%
• Safety factor (SF): 1.2
• Local loss coefficient (K): 2.5
• Steady flow at 20°C

Step-by-Step Calculation:

1. Flow Velocity:

v = Q / A = Q / (π × D² / 4)
where:
v = velocity (m/s)
Q = flow rate (m³/s)
D = pipe diameter (m)

2. Reynolds Number:

Re = (ρ × v × D) / μ
where:
ρ = fluid density (kg/m³)
μ = fluid viscosity (Pa·s)

3. Friction Factor (f):

4. For laminar flow (Re < 2300):

f = 64/Re

• For turbulent flow (Re > 4000):

1/√f = -2log₁₀(ε/3.7D + 2.51/Re√f)

where ε = pipe roughness (m)

4. Pressure Losses:

ΔP_friction = f × (L/D) × (ρv²/2)
ΔP_geodetic = ρ × g × h
ΔP_local = K × (ρv²/2)
ΔP_total = ΔP_friction + ΔP_geodetic + ΔP_local

5. Final Power Formula:

P_total = Q × ΔP_total × (1/η) × SF
where:
P_total = total power required (W)
Q = flow rate (m³/s)
ΔP_total = total pressure loss (Pa)
η = pump efficiency
SF = safety factor

Complete Formula with All Variables:

P_total = [Q × (f × (L/D) × (ρv²/2) + ρgh + K × (ρv²/2))] × (1/η) × SF
where:
Q = volumetric flow rate (m³/s)
f = friction factor (calculated from Re)
L = pipe length (m)
D = pipe diameter (m)
ρ = fluid density (kg/m³)
v = fluid velocity (m/s)
g = gravitational acceleration (9.81 m/s²)
h = height difference (m)
K = local loss coefficient
η = pump efficiency (0.7)
SF = safety factor (1.2)

Want to skip all these calculations? Use our Power Calculator for instant results. It handles all the complex math while you focus on your project.

Pro Tip: Use this tool for quick estimates during early project stages. For final pump selection, you'll want to consider additional factors like NPSH and specific pump curves.