What Is the Fay-Riddell Stagnation Point Boundary Layer Heating Calculator?
Fay-Riddell equation models laminar stagnation boundary layer heat transfer in high-enthalpy dissociated gases.
How Does the Fay-Riddell Stagnation Point Boundary Layer Heating Calculator Work?
Accounts for molecular conduction and atom diffusion driven by Lewis number scaling.
Fay-Riddell Stagnation Point Boundary Layer Heating Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
q_w = 0.763 Pr^{-0.6} (\rho_w \mu_w)^{0.1} (\rho_0 \mu_0)^{0.4} \left[1 + (Le^{0.52} - 1)\frac{h_D}{h_0}\right] (h_0 - h_w) \sqrt{\frac{du_e}{dx}}
Fay-Riddell similarity solution for laminar dissociated boundary layers.
How to Use the Fay-Riddell Stagnation Point Boundary Layer Heating Calculator
- Enter Prandtl and Lewis numbers, total and wall enthalpies, velocity gradient, and rho-mu products.
Step-by-Step Example Calculation
Hypersonic Reentry Boundary Layer
Input Values:
lewisNumber:1.4
prandtlNumber:0.71
stagnationEnthalpyJPerKg:30000000
wallEnthalpyJPerKg:2000000
velocityGradientAtStagSMinus1:8000
stagnationDensityViscosityProduct:0.0005
wallDensityViscosityProduct:0.0001
Worked Steps: Evaluates convective heat flux taking chemical recombination and enthalpy gradient into account.
Understanding Your Result
Outputs primary wall heat flux in W/cm² and kW/m².
Factors That Affect the Result
- Enthalpy potential difference (h0 - hw) and velocity gradient dominate heat flux magnitude.
When Should You Use This Calculator?
- High-fidelity hypersonic aerothermodynamics and arc-jet testing comparison.
Assumptions & Limitations
- Applies to equilibrium or frozen dissociated boundary layers at a blunt stagnation point.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Benchmark solution used across NASA, ESA, and JAXA hypersonics engineering codes.