292 lines
12 KiB
C#
292 lines
12 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 SingleCylScenario : Scenario
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{
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// ---------- Engine components ----------
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private Crankshaft crankshaft;
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private Cylinder cylinder;
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// ---------- Fluid network ----------
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private PipeSystem pipeSystem;
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private BoundarySystem boundaries;
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private Solver solver;
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// Volumes
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private Volume0D intakePlenum;
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// Ports
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private Port plenumInlet, plenumOutlet;
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// Orifice / open‑end indices
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private int throttleAreaIdx, plenumRunnerIdx, intakeValveIdx, exhaustValveIdx;
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private int intakeOpenIdx, exhaustOpenIdx;
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private float[] orificeAreas;
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// Sound
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private SoundProcessor exhaustSound, intakeSound;
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private OutdoorExhaustReverb reverb;
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// ---------- Simulation state ----------
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private double dt;
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private int stepCount;
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public float MaxThrottleArea = 100e-4f; // 1 cm²
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// ---------- Geometry (Lifan YX140) ----------
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// Bore 56 mm, Stroke 57 mm, CR 9.5
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private const float Bore = 0.056f;
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private const float Stroke = 0.057f;
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private const float ConRod = 0.110f; // typical for 57 mm stroke
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private const float CompressionRatio = 9.5f;
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// Valve diameters (intake 27 mm, exhaust 23 mm)
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private const float IntakeValveDiam = 0.027f;
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private const float ExhaustValveDiam = 0.023f;
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private const float ValveLift = 0.006f; // 6 mm peak lift
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// Valve timings (degrees, 720° four‑stroke)
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// Intake: 15° BTDC → 45° ABDC
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private const float IVO = 345f; // 15° BTDC
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private const float IVC = 585f; // 45° ABDC (180°+45°)
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// Exhaust: 45° BBDC → 15° ATDC
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private const float EVO = 135f; // 45° BBDC (180°-45°)
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private const float EVC = 375f; // 15° ATDC (360°+15°)
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// Spark advance: 30° BTDC
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private const float SparkAdv = 30f;
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// Pipe / plenum sizes
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private const float PipeDiam = 0.025f; // 25 mm intake / exhaust
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private const float PipeArea = 0.00049087f; // π*D²/4
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private const float PlenumVolume = 0.0005f; // 500 mL
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private const float MaxThrottleArea = 1e-4f; // ~1 cm² (fully open)
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// Pipe lengths and cell counts
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private const float IntakeLenBefore = 0.15f; // 15 cm before throttle
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private const float RunnerLen = 0.25f; // 25 cm runner
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private const float ExhaustLen = 0.60f; // 60 cm exhaust
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private const int CellsBefore = 6;
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private const int CellsRunner = 10;
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private const int CellsExhaust = 24;
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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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// ---- Crankshaft ----
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crankshaft = new Crankshaft(600);
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crankshaft.Inertia = 0.05f;
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crankshaft.FrictionConstant = 2f;
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crankshaft.FrictionViscous = 0.01f;
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// ---------- Cylinder ----------
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cylinder = new Cylinder(Bore, Stroke, ConRod, CompressionRatio,
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IVO, IVC, EVO, EVC, crankshaft)
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{
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IntakeValveDiameter = IntakeValveDiam,
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ExhaustValveDiameter = ExhaustValveDiam,
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IntakeValveLift = ValveLift,
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ExhaustValveLift = ValveLift,
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SparkAdvance = SparkAdv,
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EnergyVariationFraction = 0.03f, // small cycle‑to‑cycle variation
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MisfireProbability = 0.0f
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};
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// ---------- Pipe system ----------
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int totalCells = CellsBefore + CellsRunner + CellsExhaust;
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int[] pipeStart = { 0, CellsBefore, CellsBefore + CellsRunner };
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int[] pipeEnd = { CellsBefore, CellsBefore + CellsRunner, totalCells };
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float[] areas = new float[totalCells];
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float[] dxs = new float[totalCells];
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float dxBefore = IntakeLenBefore / CellsBefore;
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float dxRunner = RunnerLen / CellsRunner;
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float dxExh = ExhaustLen / CellsExhaust;
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for (int i = 0; i < totalCells; i++)
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{
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areas[i] = PipeArea;
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if (i < CellsBefore)
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dxs[i] = dxBefore;
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else if (i < CellsBefore + CellsRunner)
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dxs[i] = dxRunner;
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else
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dxs[i] = dxExh;
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}
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pipeSystem = new PipeSystem(totalCells, pipeStart, pipeEnd, area, dx,
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1.225f, 0f, 101325f);
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pipeSystem.DampingMultiplier = 1.0f;
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pipeSystem.EnergyRelaxationRate = 0.5f;
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pipeSystem.AmbientPressure = 101325f;
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// ---- Volumes ----
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intakePlenum = new Volume0D(100e-6f, 101325f, 300f); // 100 mL
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plenumInlet = intakePlenum.CreatePort();
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plenumOutlet = intakePlenum.CreatePort();
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// ---------- Boundary system ----------
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boundaries = new BoundarySystem(pipeSystem, maxOrifices: 4, maxOpenEnds: 2);
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throttleAreaIdx = 0;
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plenumRunnerIdx = 1;
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intakeValveIdx = 2;
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exhaustValveIdx = 3;
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// Open ends
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boundaries.AddOpenEnd(pipeIndex: 0, isLeftEnd: true, 101325f, PipeArea);
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intakeOpenIdx = 0;
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boundaries.AddOpenEnd(pipeIndex: 2, isLeftEnd: false, 101325f, PipeArea);
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exhaustOpenIdx = 1;
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// Orifices
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// throttle – variable area, low discharge for restriction
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boundaries.AddOrifice(plenumInlet, pipeIndex: 0, isLeftEnd: false,
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throttleAreaIdx, dischargeCoeff: 0.8f);
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// plenum → runner
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boundaries.AddOrifice(plenumOutlet, pipeIndex: 1, isLeftEnd: true,
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plenumRunnerIdx, dischargeCoeff: 1.0f);
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// intake valve
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boundaries.AddOrifice(cylinder.IntakePort, pipeIndex: 1, isLeftEnd: false,
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intakeValveIdx, dischargeCoeff: 1.0f);
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// exhaust valve
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boundaries.AddOrifice(cylinder.ExhaustPort, pipeIndex: 2, isLeftEnd: true,
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exhaustValveIdx, dischargeCoeff: 1.0f);
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orificeAreas = new float[4];
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orificeAreas[plenumRunnerIdx] = PipeArea; // fixed full‑bore
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// ---------- Solver ----------
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solver = new Solver { SubStepCount = 5, 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(cylinder);
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solver.AddComponent(intakePlenum);
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// ---- Sound ----
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exhaustSound = new SoundProcessor(sampleRate, 1f) { Gain = 20f };
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intakeSound = new SoundProcessor(sampleRate, 1f) { Gain = 20f };
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reverb = new OutdoorExhaustReverb(sampleRate);
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stepCount = 0;
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Console.WriteLine("Single‑cylinder engine (YX140) ready.");
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}
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public override float Process()
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{
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// ---- Crank and cylinder pre‑step ----
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crankshaft.Step((float)dt);
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cylinder.PreStep((float)dt);
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// ---- Update variable areas ----
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float throttledArea = MaxThrottleArea * Math.Clamp(Throttle, 0.0001f, 1.0f);
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orificeAreas[throttleAreaIdx] = throttledArea;
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orificeAreas[intakeValveIdx] = cylinder.IntakeValveArea;
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orificeAreas[exhaustValveIdx] = cylinder.ExhaustValveArea;
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boundaries.SetOrificeAreas(orificeAreas);
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// ---- Fluids step ----
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solver.Step();
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stepCount++;
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// ---- Sound ----
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float exhaustFlow = boundaries.GetOpenEndMassFlow(exhaustOpenIdx);
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float intakeFlow = boundaries.GetOpenEndMassFlow(intakeOpenIdx);
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float exhaustDry = exhaustSound.Process(exhaustFlow);
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float intakeDry = intakeSound.Process(intakeFlow);
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if (stepCount % 2000 == 0)
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{
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float rpm = crankshaft.AngularVelocity * 60f / (2f * MathF.PI);
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float crankDeg = crankshaft.CrankAngle; // public property on Cylinder
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Console.WriteLine($"Step {stepCount}, CA={crankDeg:F1} deg, RPM={rpm:F0}, CylP={cylinder.Pressure / 1e5f:F2} bar");
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Console.WriteLine($" intake flow: {intakeFlow:F6}, exhaust flow: {exhaustFlow:F6}");
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// Pipe 0 (intake before throttle)
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var (r0L, u0L, p0L) = pipeSystem.GetInteriorStateLeft(0);
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var (r0R, u0R, p0R) = pipeSystem.GetInteriorStateRight(0);
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Console.WriteLine($" Pipe0 L: rho={r0L:F4} u={u0L:F3} p={p0L/1e5:F3}bar | R: rho={r0R:F4} u={u0R:F3} p={p0R/1e5:F3}bar");
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// Pipe 1 (runner)
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var (r1L, u1L, p1L) = pipeSystem.GetInteriorStateLeft(1);
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var (r1R, u1R, p1R) = pipeSystem.GetInteriorStateRight(1);
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Console.WriteLine($" Pipe1 L: rho={r1L:F4} u={u1L:F3} p={p1L/1e5:F3}bar | R: rho={r1R:F4} u={u1R:F3} p={p1R/1e5:F3}bar");
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// Pipe 2 (exhaust)
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var (r2L, u2L, p2L) = pipeSystem.GetInteriorStateLeft(2);
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var (r2R, u2R, p2R) = pipeSystem.GetInteriorStateRight(2);
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Console.WriteLine($" Pipe2 L: rho={r2L:F4} u={u2L:F3} p={p2L/1e5:F3}bar | R: rho={r2R:F4} u={u2R:F3} p={p2R/1e5:F3}bar");
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// Plenum and cylinder mass
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Console.WriteLine($" Plenum P={intakePlenum.Pressure/1e5:F3}bar, mass={intakePlenum.Mass:E4} kg");
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Console.WriteLine($" Cyl mass={cylinder.Mass:E4} kg");
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}
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return reverb.Process(intakeDry + exhaustDry);
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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 intakeY = winH / 2f - 40f;
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float exhaustY = winH / 2f + 80f;
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float leftX = 40f;
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// Intake open end marker
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var om = new CircleShape(5f) { FillColor = Color.Cyan };
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om.Position = new Vector2f(leftX - 5f, intakeY - 5f);
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target.Draw(om);
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// Pipe 0 – before throttle
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float p0EndX = leftX + 80f;
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DrawPipe(target, pipeSystem, 0, intakeY, leftX, p0EndX);
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// Throttle symbol
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float thrX = p0EndX + 5f;
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var thr = new RectangleShape(new Vector2f(8f, 30f))
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{
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FillColor = Color.Yellow,
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Position = new Vector2f(thrX, intakeY - 15f)
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};
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target.Draw(thr);
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// Plenum volume
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float plenW = 60f, plenH = 50f;
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float plenLeftX = thrX + 12f;
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float plenCenterX = plenLeftX + plenW / 2f;
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float plenTopY = intakeY - plenH / 2f;
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DrawVolume(target, intakePlenum, plenCenterX, plenTopY, plenW, plenH);
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// Pipe 1 – runner
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float rStartX = plenLeftX + plenW + 10f;
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float rEndX = rStartX + 100f;
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DrawPipe(target, pipeSystem, 1, intakeY, rStartX, rEndX);
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// Cylinder
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float cylCX = rEndX + 50f;
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float cylTopY = intakeY - 120f;
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float cylW = 80f, cylMaxH = 240f;
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DrawCylinder(target, cylinder, cylCX, cylTopY, cylW, cylMaxH);
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// Pipe 2 – exhaust
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float exhStartX = cylCX + cylW / 2f + 20f;
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float exhEndX = winW - 60f;
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DrawPipe(target, pipeSystem, 2, exhaustY, exhStartX, exhEndX);
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// Exhaust open end
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var em = new CircleShape(5f) { FillColor = Color.Magenta };
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em.Position = new Vector2f(exhEndX - 5f, exhaustY - 5f);
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target.Draw(em);
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}
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}
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} |