🚿 Spray & Droplet Atomization
Calculate Sauter Mean Diameter (SMD, D32), liquid jet breakup regimes (Rayleigh, Wind-Induced, Atomization), spray cone angle, Rosin-Rammler droplet distribution, Weber and Ohnesorge numbers.
⚡ Fortran 90 Engine
Double Precision (IEEE 754)
✓ ISO / ASME Validated
📊 Solver Telemetry
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⚡ Calculs faits
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📦 Code Fortran
4.5 KB
📅 Mise en service
Aug 2026
⏱️ Latence
< 1 ms
🚿 Spray Jet & Droplet Atomization Dynamics
Real-time particle & wave breakup simulation📝 Configuration & Presets
Key Formulations:
• Velocity: Vinj = Cd √(2ΔP/ρL)
• Sauter Mean Diameter: D32 = 2.25 σ0.25 μL0.16 ρL0.20 ṁ0.22 ΔP−0.43
• Weber Number: Weg = ρg Vinj² d0 / σ
• Ohnesorge Number: Oh = μL / √(ρL σ d0)
• Velocity: Vinj = Cd √(2ΔP/ρL)
• Sauter Mean Diameter: D32 = 2.25 σ0.25 μL0.16 ρL0.20 ṁ0.22 ΔP−0.43
• Weber Number: Weg = ρg Vinj² d0 / σ
• Ohnesorge Number: Oh = μL / √(ρL σ d0)
📊 Atomization & Spray Results
📊 Output Summary
Identified Breakup Regime
Second Wind-Induced Regime
Turbulent shearing and short-wavelength wave stripping; droplets smaller than nozzle diameter.
Sauter Mean Diameter (D32)
2916.0 µm
MMD (Dv50) = 3440.9 µm
Spray Cone Angle (θ)
39.9°
Liquid Core Length = 303.6 mm
Injection Velocity (Vinj)
20.82 m/s
Flow = 3.679e-2 kg/s (2.21 L/min)
Dimensionless Numbers
Weg = 17.3 | Oh = 0.0038
ReL = 3.12e+4 | WeL = 1.44e+4
📈 Rosin-Rammler Droplet Size Distribution
📉 Sauter Mean Diameter D32 vs Injection ΔP
================================================================= THERMOFLUIDCALC — SPRAY & DROPLET ATOMIZATION REPORT ================================================================= Case Title : Agricultural Flat-Fan Spray Nozzle Nozzle Orifice Diameter : 1.500 mm (1.5000e-3 m) Injection Pressure Drop : 3.00 bar (3.000e+5 Pa) Discharge Coefficient Cd : 0.850 ----------------------------------------------------------------- Liquid Velocity (V_inj) : 20.821 m/s Mass Flow Rate (mdot) : 3.6793e-2 kg/s (36.793 g/s) Volumetric Flow Rate (Q) : 3.6793e-5 m3/s (2.208 L/min) ----------------------------------------------------------------- Liquid Reynolds Number ReL : 3.123e+4 Liquid Weber Number WeL : 1.445e+4 Gas Weber Number Weg : 1.734e+1 Ohnesorge Number Oh : 0.00385 Breakup Regime : Second Wind-Induced Regime ----------------------------------------------------------------- Sauter Mean Diameter (D32) : 2916.03 microns (µm) Arithmetic Mean (D10) : 1895.42 microns (µm) Mass Median Diameter (Dv50): 3440.92 microns (µm) Spray Cone Angle : 39.89 deg Liquid Core Breakup Length : 303.58 mm =================================================================
📘 Calculation Methodology & Engineering Theory
Breakup Regimes & Ohnesorge Diagram
The transition from a continuous liquid column to finely dispersed droplets is governed by the competing forces of inertia, surface tension, viscous shear, and aerodynamic drag:
- Rayleigh Regime (Oh < 0.1, WeL < 10): Capillary instabilities pinch off droplets larger than the nozzle.
- First & Second Wind-Induced: Aerodynamic interaction with surrounding gas causes surface wave shearing.
- Catastrophic Atomization (Weg > 40): Instantaneous chaotic stripping of ligaments into micro-droplets.
Sauter Mean Diameter (D32)
The Sauter Mean Diameter represents the ratio of droplet volume to surface area, critical for mass transfer, evaporation, and combustion:
D32 = ∑ di³ / ∑ di² = 2.25 · σ0.25 · μL0.16 · ρL0.20 · ṁL0.22 · ΔP−0.43
The cumulative volumetric distribution follows the Rosin-Rammler distribution with dispersion parameter q ≈ 2.85.
Key Engineering Assumptions
- Single-component liquid atomizing in a stagnant or co-flowing gas.
- Newtonian liquid behavior (constant dynamic viscosity μL).
- Pressure-swirl / plain orifice discharge correlation valid for ReL > 500.
- Secondary droplet coalescence and wall impingement are not modeled.