PPolySim OS
Electronics & Power Pack · Multi-Solver

Transmission Sag

Thermal & clearance. This multi-solver chains 2 solvers into a single guided workflow — run each step in order and carry the result forward.

Workflow steps
  1. thermal-expansion
  2. transmission-line
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1

Thermal Expansion

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Thermal ExpansionLive

Controls

Presets

Heat a material and it expands: ΔL = α·L·ΔT, where α is the coefficient of linear expansion. Area grows at twice that rate and volume at three times. It is why bridges have expansion joints, why rails buckle in heat, and why Invar — with almost zero expansion — is prized for precision instruments.

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Data Inspector

α23 µm/m·°C
Length change11.5 mm
Area change0.230 m²
Volume change3.450 m³

Governing equation

Reading this result: Heating 10 m of Aluminum by 50°C stretches it about 11.5 mm; area and volume grow 2× and 3× as fast.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

2

Transmission Line

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Transmission Line & VSWRLive

Controls

Presets

When a transmission line meets a load that does not match its impedance, part of the wave reflects. Incident and reflected waves combine into a standing-wave pattern measured by the VSWR. A perfect match (RL = Z₀, XL = 0) gives VSWR 1 and no reflection — the goal of every antenna and RF design.

▶ Run in Python

Data Inspector

Reflection |Γ|0.200
VSWR1.50 : 1
Return loss14.0 dB
Matchpoor

Governing equation

Reading this result: A large resistive mismatch reflects much of the wave, giving a high VSWR and deep nulls in the standing-wave pattern.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Frequently asked questions

What is the Transmission Sag multi-solver?
Transmission Sag is a guided workflow that chains 2 individual PolySim solvers into one end-to-end analysis, piping each result into the next step.
Is it free to use?
Yes. Every step runs entirely in your browser using real numerics — no install, no account, no cloud cost. Custom or private solver packs are available as a paid service.