🛡️ Cryogenic Multilayer Insulation (MLI)

Size spacecraft and cryogenic Multilayer Insulation (MLI) blankets, computing total heat flux (W/m²), effective thermal conductivity keff, and daily cryogen boil-off rate (LH2, LN2, LHe).

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

📊 Solver Telemetry ● ACTIVE

👁️ Consultations 18

⚡ Calculs faits 16

💾 Téléchargements 321 📦 Code Fortran 5.4 KB

📅 Mise en service Jun 2026

⏱️ Latence < 1 ms

🛡️ Vacuum Multilayer Radiation Shields & Cryogenic Barrier

Real-time visual simulation of reflective foil radiation bounces, Dacron spacer mesh & residual gas conduction

📝 Configuration & Presets

🚀 Liquid H2 (LH2) Rocket Tank ❄️ Liquid N2 (LN2) Dewar 🧲 Superconducting MRI (LHe) 🛰️ GEO Satellite Blanket

📐 MLI Blanket Geometry

Number of Shield Layers N:

Total Thickness Δx [mm]:

🌡️ Boundary Temperatures & Emissivity

Warm Boundary Temp T_h [K]:

Cold Cryo Temp T_c [K]:

Foil Surface Emissivity ε:

Vacuum Pressure [Torr]: High vacuum < 10⁻⁴ Torr

💧 Cryogenic Tank Sizing

Tank Outer Area A [m²]:

Cryogen Latent Heat h_fg [kJ/kg]:

Lockheed / McIntosh MLI Formulation:
• Radiation: q″_rad = σ (T_h⁴ − T_c⁴) / [ (N+1)(2/ε − 1) ]
• Solid Spacers: q″_solid = 7.3×10⁻⁵ N̄^2.63 T_mean ΔT / N
• Residual Gas: q″_gas = 14600 P_vac (T_h^0.52 − T_c^0.52) / N
• Effective Conductivity: k_eff = q″_tot · Δx / (T_h − T_c) [W/(m·K)]

📊 MLI Thermal Results

📊 Output Summary
💾 Fortran Source

Total MLI Heat Flux (q″_tot)

q″ = 348.945 W/m²

Effective Conductivity: 1.92e-2 W/(m·K) | Boil-Off: 606.01 kg/day

N = 25 layers (20.8 L/cm)

Radiation Component (q″_rad) 0.293 W/m² 0.1 % of total

Solid Spacer Conduction 348.087 W/m² 99.8 % of total

Residual Gas Conduction 0.565 W/m² 0.2 % of total

Daily Cryogen Boil-Off 606.01 kg/day Tank area A = 4 m²

📈 Total MLI Heat Flux q″ (W/m²) vs Number of Shields N

📉 Effective Conductivity k_eff (×10⁻⁵ W/m·K) vs log₁₀(P_vac)

=================================================================
 THERMOFLUIDCALC — CRYOGENIC MULTILAYER INSULATION (MLI) REPORT
=================================================================
Case Title                 : Laboratory Liquid Nitrogen (LN2) Storage Cryostat Dewar
Blanket Configuration      : N = 25 layers, Thickness = 12.0 mm (Density = 20.8 layers/cm)
Thermal Boundaries         : Warm Th = 295.0 K, Cold Tc = 77.0 K (DeltaT = 218.0 K)
Vacuum & Surface Properties: Emissivity eps = 0.035, Vacuum Pressure = 1.00e-4 Torr
-----------------------------------------------------------------
TOTAL HEAT FLUX (q_tot)    : 348.9448 W/m2
 - Radiation Flux (q_rad)  : 0.2928 W/m2 (0.1%)
 - Solid Conduction (q_sol): 348.0870 W/m2 (99.8%)
 - Gas Conduction (q_gas)  : 0.5649 W/m2 (0.2%)
EFFECTIVE CONDUCTIVITY keff: 1.921e-2 W/(m.K)
Cryogen Daily Boil-Off Rate: 606.007 kg/day
=================================================================

📘 Calculation Methodology & Cryogenic MLI Standards

Lockheed & McIntosh Semi-Empirical Model

Decomposes heat transfer through vacuum multilayer insulation into three distinct parallel mechanisms:

                    q″total = q″radiation + q″solid_spacers + q″residual_gas
                

Optimum Layer Density

Increasing shield density $\bar{N}$ suppresses radiation but increases solid spacer contact conduction. Optimum density is typically $20 - 30\,\text{layers/cm}$.

Key Engineering Assumptions

Double-aluminized Mylar (DAM) or Kapton with Dacron mesh spacers.
Free-molecular regime for residual gas ($Kn \gg 10$ at $P < 10^{-4}\,\text{Torr}$).
Applicable to $LH_2, LN_2, LHe, LOX, LCH_4$ storage and satellites.

ThermoFluidCalc Engineering Report