📉 Transient Conduction 1D — Heisler Charts

Analyze transient heat conduction using the one-term approximation for plane walls, long cylinders, and spheres.

📝 Configuration

Material Properties

Boundary Conditions

Still air: 5-10 · Forced air: 25-250 · Water: 50-10000

Analysis Point

Current value: 0
One-Term Approximation (Fo > 0.2):

Wall: θ* = C₁·e-ζ₁²Fo·cos(ζ₁·x/L)
Cyl: θ* = C₁·e-ζ₁²Fo·J₀(ζ₁·r/r₀)
Sphere: θ* = C₁·e-ζ₁²Fo·sin(ζ₁·r/r₀)/(ζ₁·r/r₀)

• Bi = hL/k · Fo = αt/L²
• θ* = (T-T∞)/(Tᵢ-T∞)

📊 Results & Visualization

Results and visualizations will appear here after calculation.

ℹ️ About the One-Term Approximation

For Fourier number Fo > 0.2, the infinite series solution converges to a single dominant term, giving accurate results (< 2% error).

Eigenvalue equations:
• Wall: ζₙ·tan(ζₙ) = Bi
• Cylinder: ζₙ·J₁(ζₙ)/J₀(ζₙ) = Bi
• Sphere: 1 - ζₙ·cot(ζₙ) = Bi

Applications:
• Heat treatment of metals
• Food sterilization processes
• Thermal protection systems
• Concrete curing analysis