What Is the Weber Number (We) Droplet Breakup Calculator?
The Weber number is a dimensionless quantity in fluid mechanics often used in analyzing fluid flows where there is an interface between two different fluids.
How Does the Weber Number (We) Droplet Breakup Calculator Work?
Evaluates dynamic pressure ρ · v².
Calculates ratio to surface tension per unit length σ / d.
Classifies secondary breakup mode: vibrational (We < 12), bag (12-50), bag-and-stamen (50-100), stripping (100-350), or catastrophic (We > 350).
Weber Number (We) Droplet Breakup Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
We = (ρ_gas · v² · d) / σ
Ratio of aerodynamic dynamic pressure forces to cohesive surface tension forces.
How to Use the Weber Number (We) Droplet Breakup Calculator
- Enter gas density, relative velocity, droplet diameter, and surface tension.
Step-by-Step Example Calculation
Fuel Injector Spray Atomization
Input Values:
density:1.2
velocity:30
dropletDiameter:1
surfaceTension:0.03
Worked Steps: 1 mm droplet moving at 30 m/s yielding We = 36 (Bag Breakup regime).
Understanding Your Result
Displays Weber number and diagnostic breakup regime.
Factors That Affect the Result
- Relative speed (We scales with velocity squared v²).
When Should You Use This Calculator?
- Gas turbine spray nozzles, agricultural sprayers, and aerosol generation.
Assumptions & Limitations
- Applies to low-viscosity droplets (O counters Ohnesorge number Oh < 0.1).
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard Pilch and Erdman atomization classification.