Research Note — RES‑004
Laminar Boundary Layer — Similarity Solution & Convective Heat Transfer
Two related studies in laminar convection: Stokes' first problem for an impulsively started flat plate, and the Blasius similarity solution for the momentum and thermal boundary layers over a flat plate — both solved numerically in MATLAB, with streamlines and heatlines used to visualize the flow and heat‑transfer paths.
Part 1
Stokes' First Problem — Penetration Depth
- Solved for the momentum penetration depth using the error function (
erf) and its inverse (erfinv) - Compared penetration depth across velocity ratios (u/U₀) from 0.001 to 0.1
- Solved the transient velocity profile for time steps of 10, 20, 30, 40 and 50 seconds
Part 2
Blasius Similarity Solution — Flat‑Plate Boundary Layer
- Reduced the momentum similarity equation 2f‴ + ff″ = 0 and thermal equation θ″ + (Pr/2)fθ′ = 0 to first‑order systems
- Solved both with the shooting method in MATLAB (
ode45+fsolveto close the unknown boundary condition) - Compared velocity profiles along the plate for free‑stream velocities of 1 m/s and 3 m/s
- Derived the stream function and plotted streamlines for uniform flow over the flat plate
- Derived the heat function (Morega & Bejan method) and plotted heatlines to visualize the heat‑transfer path
2f‴ + ff″ = 0 · θ″ + (Pr/2)fθ′ = 0
Code
MATLAB Script
similarity_boundary_layer.m — shooting‑method solver for both the momentum and thermal similarity equations, plus streamline/heatline plotting.
Download .m