Bernoulli Equation Calculator

Calculate pressure, velocity, and height changes in fluid flow using Bernoulli's principle

Bernoulli Equation Calculator

Choose which parameter to calculate using Bernoulli's equation

Fluid Properties

Water: 1000 kg/m³, Air: 1.225 kg/m³

Earth: 9.80665 m/s², Moon: 1.62 m/s²

Position 1 (Initial Point)

Position 2 (Final Point)

Pa
m
m/s

Flow Rate Analysis (Optional)

cm

Bernoulli Equation Results

Calculated Value

1.897 m/s
Velocity at Position 2

Pressure Change

200.0 Pa
Pressure Increase
56.55 m³/h
Volumetric Flow Rate
56548.7 kg/h
Mass Flow Rate
78.5 cm²
Cross-sectional Area 1

Energy Conservation Check

✅ Energy Conserved
Total Energy 1: 32419.9 J/m³
Total Energy 2: 32419.9 J/m³

Bernoulli's Equation: p₁ + ½ρv₁² + ρgh₁ = p₂ + ½ρv₂² + ρgh₂

Where: p = pressure, ρ = density, v = velocity, g = gravity, h = height

Flow Rate: Q = A × v = π(d/2)² × v

Flow Analysis

📈 Pressure increases from position 1 to position 2
🌊 Flow rate: 56.55 m³/h

Example Calculation - Water Flow in Pipe

Given Parameters

Fluid: Water (ρ = 1000 kg/m³)

Position 1: p₁ = 1000 Pa, h₁ = 3 m, v₁ = 2 m/s

Position 2: p₂ = 1200 Pa, h₂ = 3 m, v₂ = ?

Gravity: g = 9.80665 m/s²

Calculation Steps

Step 1: Apply Bernoulli's equation

p₁ + ½ρv₁² + ρgh₁ = p₂ + ½ρv₂² + ρgh₂

Step 2: Substitute known values

1000 + ½(1000)(2²) + (1000)(9.807)(3) = 1200 + ½(1000)v₂² + (1000)(9.807)(3)

Step 3: Simplify and solve for v₂

1000 + 2000 + 29420 = 1200 + 500v₂² + 29420

32420 = 30620 + 500v₂² → v₂² = 3.6 → v₂ = 1.897 m/s

Common Fluid Densities

Water (20°C)1000 kg/m³
Air (20°C)1.225 kg/m³
Ethanol789 kg/m³
Gasoline750 kg/m³
Mercury13534 kg/m³

Applications

✈️

Airplane Wings: Explaining lift generation

🚰

Water Systems: Pump design and pipe flow

🌪️

Venturi Effect: Flow measurement devices

Magnus Effect: Ball trajectory in sports

🏎️

Aerodynamics: Car and aircraft design

Understanding Bernoulli's Equation

What is Bernoulli's Principle?

Bernoulli's principle states that for an incompressible, steady flow of fluid, the total mechanical energy remains constant along a streamline. This means that as the speed of a fluid increases, its pressure decreases, and vice versa.

Key Assumptions

  • Fluid is incompressible (constant density)
  • Flow is steady (no time-dependent changes)
  • Fluid is inviscid (no viscosity effects)
  • Flow is along a streamline

Bernoulli's Equation

p + ½ρv² + ρgh = constant

  • p: Static pressure (Pa)
  • ρ: Fluid density (kg/m³)
  • v: Flow velocity (m/s)
  • g: Gravitational acceleration (m/s²)
  • h: Height above reference level (m)

Energy Terms

  • p: Pressure energy per unit volume
  • ½ρv²: Kinetic energy per unit volume
  • ρgh: Potential energy per unit volume

Note: Energy conservation applies along streamlines, not across them

Real-World Applications

Venturi Effect

Flow Constriction

When fluid flows through a constricted section, velocity increases and pressure decreases. Used in carburetors, flow meters, and aspirators.

Airplane Lift

Wing Design

Curved wing shape causes faster airflow over the top surface, creating lower pressure and generating lift force.