118 lines
4.0 KiB
C#
118 lines
4.0 KiB
C#
using FluidSim.Components;
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using FluidSim.Core;
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using FluidSim.Interfaces;
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using SFML.Graphics;
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using SFML.System;
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using System;
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namespace FluidSim.Tests
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{
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public class HelmholtzScenario : Scenario
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{
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private Volume0D cavity;
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private Port cavityPort;
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private PipeSystem pipeSystem;
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private int[] pipeStart = { 0 };
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private int[] pipeEnd;
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private BoundarySystem boundaries;
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private int cavityOrificeIdx = 0;
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private int openEndIdx = 0;
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private Solver solver;
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private double dt;
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private int stepCount;
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private SoundProcessor soundProcessor;
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public override void Initialize(int sampleRate)
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{
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dt = 1.0 / sampleRate;
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// --- Realistic Helmholtz resonator dimensions ---
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float cavityVolume = 1e-3f; // 1 liter
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float neckLength = 0.05f; // 5 cm
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float neckDiameter = 0.02f; // 2 cm diameter
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float neckArea = MathF.PI * 0.25f * neckDiameter * neckDiameter;
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int neckCells = 20;
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// --- Volume (cavity) ---
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float initialPressure = 1.1f * 101325f; // slight overpressure
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float initialTemperature = 300f;
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cavity = new Volume0D(cavityVolume, initialPressure, initialTemperature);
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cavityPort = cavity.CreatePort();
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// --- Pipe (neck) ---
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float[] areas = new float[neckCells];
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float[] dxs = new float[neckCells];
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float dx = neckLength / neckCells;
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for (int i = 0; i < neckCells; i++)
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{
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areas[i] = neckArea;
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dxs[i] = dx;
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}
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pipeEnd = new[] { neckCells };
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float rho0 = 101325f / (287f * 300f);
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pipeSystem = new PipeSystem(neckCells, pipeStart, pipeEnd, areas, dxs, rho0, 0f, 101325f);
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// --- Boundary system ---
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boundaries = new BoundarySystem(pipeSystem, maxOrifices: 1, maxOpenEnds: 1);
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// Standard orifice with built‑in minor loss (K = 0.5) – no inertance needed
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boundaries.AddOrificeWithInertance(
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cavityPort, pipeIndex: 0, isLeftEnd: true,
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areaIndex: cavityOrificeIdx,
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dischargeCoeff: 0.9f,
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effectiveLength: neckLength // physical neck length
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);
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// Open end at right side of pipe
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boundaries.AddOpenEnd(pipeIndex: 0, isLeftEnd: false, 101325f, neckArea);
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float[] orificeAreas = new float[1] { neckArea };
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boundaries.SetOrificeAreas(orificeAreas);
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// --- Solver ---
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solver = new Solver { SubStepCount = 8, EnableProfiling = false };
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solver.SetTimeStep(dt);
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solver.SetPipeSystem(pipeSystem);
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solver.SetBoundarySystem(boundaries);
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solver.AddComponent(cavity);
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// --- Sound ---
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soundProcessor = new SoundProcessor(sampleRate, 1f) { Gain = 2f };
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Console.WriteLine("Helmholtz resonator ready.");
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stepCount = 0;
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}
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public override float Process()
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{
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solver.Step();
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stepCount++;
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float flow = boundaries.GetOpenEndMassFlow(openEndIdx);
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float sample = soundProcessor.Process(flow);
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return sample;
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}
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public override void Draw(RenderWindow target)
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{
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float winW = target.GetView().Size.X;
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float winH = target.GetView().Size.Y;
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float cavityCenterX = 100f;
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float cavityWidth = 80f, cavityHeight = 100f;
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float cavityTopY = winH / 2f - cavityHeight / 2f;
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DrawVolume(target, cavity, cavityCenterX, cavityTopY - 40f, cavityWidth, cavityHeight);
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float pipeStartX = cavityCenterX + cavityWidth / 2f + 10f;
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float pipeEndX = winW - 50f;
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float pipeCenterY = winH / 2f;
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DrawPipe(target, pipeSystem, 0, pipeCenterY, pipeStartX, pipeEndX);
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}
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}
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} |