Boundary Element Method Calculator for Physics Problems

Analyze boundary discretization for electrostatics, heat, and flow. Compare panel density, memory, and solver effort. Get usable results, tables, downloads, formulas, and plots fast.

Boundary Element Method Calculator

Plotly Graph

The graph shows the circular benchmark potential along the x-axis.

Formula Used

The calculator focuses on boundary-only discretization planning for Laplace-type physics problems. It estimates mesh density, dense matrix size, memory demand, and approximate computational effort before you build a full simulation model.

For a circle, the boundary length is P = 2πR. For a rectangle, the boundary length is P = 2(W + H). For a custom boundary, you enter the total length directly.

The base panel count is computed from N = ceil(P / Le), where Le is the target element length. The refinement factor multiplies that count. The actual panel length is h = P / N.

The degree-of-freedom estimate uses DOF = N × f, where f equals 1 for constant elements, 2 for linear elements, and 3 for quadratic elements.

The dense influence matrix requires DOF² stored entries. Memory is estimated from Memory = DOF² × bytes × copies × safety factor. Dense direct work is approximated by (2/3)DOF³. Iterative work is approximated by iterations × DOF².

When you choose a circular boundary with Dirichlet data, the page also evaluates a simple first-harmonic benchmark. The assumed boundary condition is φ(θ) = φ̄ + A cosθ. Inside the circle, the benchmark potential becomes φ(r,θ) = φ̄ + A(r/R)cosθ. Outside the circle, it becomes φ(r,θ) = φ̄ + A(R/r)cosθ.

How to Use This Calculator

  1. Choose the physics family that matches your Laplace-type problem.
  2. Select a boundary geometry and enter the required size values.
  3. Set a target element length for the boundary mesh.
  4. Increase the refinement factor when you need tighter boundary resolution.
  5. Select constant, linear, or quadratic elements based on desired accuracy.
  6. Enter boundary average value and first-harmonic amplitude for a benchmark study.
  7. Specify the evaluation point where you want an estimated benchmark field value.
  8. Choose memory copies, bytes per entry, and solver assumptions.
  9. Press the calculate button to place the result block above the form.
  10. Download the summary as CSV or PDF when you need a saved report.

Example Data Table

Case Geometry Boundary length Target element length Panels DOFs Estimated memory (MB)
Benchmark A Circle, R = 1.00 6.2832 0.2000 32 64 0.0625
Benchmark B Rectangle, 2.00 × 1.00 6.0000 0.1500 40 80 0.0977
Benchmark C Circle, R = 2.00 12.5664 0.2500 56 112 0.1914
Benchmark D Custom boundary 8.5000 0.1250 68 136 0.2823

Frequently Asked Questions

1. What does this calculator estimate?

It estimates boundary length, panel count, degrees of freedom, dense matrix size, memory demand, approximate solver work, and a circular benchmark field when that simplified case applies.

2. Is this a complete production BEM solver?

No. It is a planning and benchmarking tool. It helps size a model, compare discretization choices, and inspect a simple analytical check before building a full boundary element implementation.

3. Why can degrees of freedom exceed the number of panels?

Higher-order elements carry more unknowns per panel. Constant elements use one factor, linear elements use two, and quadratic elements use three in this estimator.

4. Why does memory rise so quickly?

Classical BEM often stores dense influence matrices. Dense storage grows with the square of the unknown count, so larger boundary meshes become expensive quickly.

5. When should I use the circular benchmark values?

Use them when your boundary is circular and your boundary data can be approximated by a mean value plus a first cosine harmonic. That makes the benchmark physically interpretable.

6. How many panels are enough?

Start with a panel length that resolves curvature and boundary variation well. Then refine until the memory estimate, field behavior, and your own convergence checks become acceptable.

7. Should I prefer direct or iterative solving?

Direct solving is robust for modest systems. Iterative methods become attractive as the model grows, especially when memory pressure or repeated solves matter more than setup simplicity.

8. Can I export the results?

Yes. After a calculation, use the CSV button for spreadsheet work or the PDF button for a compact report you can archive or share.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.