CFD — Mesh Refinement

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 520 280" width="520" height="280">
  <style>
    text { font:12px Inter, sans-serif; fill:#0f172a; font-weight:600; }
    line.g { stroke:#94a3b8; stroke-width:0.7; }
    line.f { stroke:#3666ff; stroke-width:0.7; }
    path.air { fill:#0f172a; }
  </style>
  <!-- Coarse grid -->
  <g>
    <line class="g" x1="20"  y1="40"  x2="500" y2="40"/>
    <line class="g" x1="20"  y1="80"  x2="500" y2="80"/>
    <line class="g" x1="20"  y1="120" x2="500" y2="120"/>
    <line class="g" x1="20"  y1="160" x2="500" y2="160"/>
    <line class="g" x1="20"  y1="200" x2="500" y2="200"/>
    <line class="g" x1="20"  y1="240" x2="500" y2="240"/>
    <line class="g" x1="20"  y1="40"  x2="20"  y2="240"/>
    <line class="g" x1="100" y1="40"  x2="100" y2="240"/>
    <line class="g" x1="180" y1="40"  x2="180" y2="240"/>
    <line class="g" x1="260" y1="40"  x2="260" y2="240"/>
    <line class="g" x1="340" y1="40"  x2="340" y2="240"/>
    <line class="g" x1="420" y1="40"  x2="420" y2="240"/>
    <line class="g" x1="500" y1="40"  x2="500" y2="240"/>
  </g>
  <!-- Fine grid near airfoil -->
  <g>
    <line class="f" x1="180" y1="100" x2="320" y2="100"/>
    <line class="f" x1="180" y1="110" x2="320" y2="110"/>
    <line class="f" x1="180" y1="120" x2="320" y2="120"/>
    <line class="f" x1="180" y1="130" x2="320" y2="130"/>
    <line class="f" x1="180" y1="140" x2="320" y2="140"/>
    <line class="f" x1="180" y1="150" x2="320" y2="150"/>
    <line class="f" x1="180" y1="160" x2="320" y2="160"/>
    <line class="f" x1="180" y1="100" x2="180" y2="160"/>
    <line class="f" x1="200" y1="100" x2="200" y2="160"/>
    <line class="f" x1="220" y1="100" x2="220" y2="160"/>
    <line class="f" x1="240" y1="100" x2="240" y2="160"/>
    <line class="f" x1="260" y1="100" x2="260" y2="160"/>
    <line class="f" x1="280" y1="100" x2="280" y2="160"/>
    <line class="f" x1="300" y1="100" x2="300" y2="160"/>
    <line class="f" x1="320" y1="100" x2="320" y2="160"/>
  </g>
  <!-- Airfoil -->
  <path class="air" d="M200,130 Q240,110 290,130 Q260,140 200,130 Z"/>
  <text x="20" y="270">Coarse far-field grid · refined boundary layer near airfoil</text>
</svg>