266 lines
11 KiB
C#
266 lines
11 KiB
C#
using FluidSim.Components;
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using FluidSim.Core;
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using FluidSim.Interfaces;
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using FluidSim.Utils;
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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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private Crankshaft crankshaft;
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private Cylinder cylinder;
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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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private Volume0D intakePlenum;
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private Port plenumInlet, plenumOutlet;
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private Volume0D exhaustCollector;
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private Port colIn, colOut;
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private int throttleAreaIdx, plenumRunnerAreaIdx, intakeValveIdx, exhaustValveIdx;
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private float[] orificeAreas;
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private int intakeOpenIdx, exhaustOpenIdx;
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private SoundProcessor exhaustSound, intakeSound;
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private OutdoorExhaustReverb reverb;
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private double dt;
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private int stepCount;
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private float _maxThrottleArea;
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private float intakePipeArea, exhaustPipeArea;
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private const float MaxBrakeTorque = 30.0f; // Nm at full load
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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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// Throttle body diameter 44mm (typical for 250cc MX)
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_maxThrottleArea = (float)Units.AreaFromDiameter(44 * Units.mm);
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// ---- Crankshaft ----
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crankshaft = new Crankshaft(2000);
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crankshaft.Inertia = 0.02f; // kg·m² (crank + flywheel)
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crankshaft.FrictionConstant = 3.0f; // Nm – bearings, rings, seals
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crankshaft.FrictionViscous = 0.002f; // Nm/(rad/s) – oil windage
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// ---- Cylinder (CRF250R) ----
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float bore = 0.078f; // 78 mm
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float stroke = 0.0522f; // 52.2 mm → 249.4 cc
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float conRod = 0.1044f; // 2× stroke
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float compRatio = 13.5f; // typical
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// Valve events (high‑performance MX cam)
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float ivo = 340f, ivc = 600f; // intake opens 20° BTDC (overlap), closes 60° ABDC
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float evo = 120f, evc = 380f; // exhaust opens 60° BBDC, closes 20° ATDC
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cylinder = new Cylinder(bore, stroke, conRod, compRatio,
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ivo, ivc, evo, evc, crankshaft)
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{
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IntakeValveDiameter = 0.036f, // 36 mm
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IntakeValveLift = 0.0095f, // 9.5 mm
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ExhaustValveDiameter = 0.030f, // 30 mm
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ExhaustValveLift = 0.0085f // 8.5 mm
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};
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// ---- Pipe system ----
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int[] pipeStart = { 0, 10, 20 };
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int[] pipeEnd = { 10, 20, 70 };
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int totalCells = pipeEnd[^1];
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float[] area = new float[totalCells];
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float[] dx = new float[totalCells];
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float intakeDia = 0.040f; // 40 mm intake runner
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float exhaustDia = 0.038f; // 38 mm exhaust primary
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intakePipeArea = MathF.PI * 0.25f * intakeDia * intakeDia;
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exhaustPipeArea = MathF.PI * 0.25f * exhaustDia * exhaustDia;
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float intakeLenBefore = 0.15f; // throttle body to plenum
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float intakeLenRunner = 0.25f; // plenum to valve
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float exhaustLen = 0.50f; // exhaust length
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for (int i = 0; i < totalCells; i++)
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{
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if (i < 10)
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{
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area[i] = intakePipeArea; dx[i] = intakeLenBefore / 10f;
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}
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else if (i < 20)
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{
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area[i] = intakePipeArea; dx[i] = intakeLenRunner / 10f;
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}
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else
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{
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area[i] = exhaustPipeArea; dx[i] = exhaustLen / 50f;
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}
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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(1.0e-3f, 101325f, 300f); // 1 litre airbox
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plenumInlet = intakePlenum.CreatePort();
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plenumOutlet = intakePlenum.CreatePort();
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exhaustCollector = new Volume0D(10e-6f, 101325f, 800f); // unused
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colIn = exhaustCollector.CreatePort();
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colOut = exhaustCollector.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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plenumRunnerAreaIdx = 1;
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intakeValveIdx = 2;
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exhaustValveIdx = 3;
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// Open ends (pipe area = pipe cross‑section)
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boundaries.AddOpenEnd(pipeIndex: 0, isLeftEnd: true, 101325f, intakePipeArea);
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intakeOpenIdx = 0;
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boundaries.AddOpenEnd(pipeIndex: 2, isLeftEnd: false, 101325f, exhaustPipeArea);
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exhaustOpenIdx = 1;
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// Orifices
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boundaries.AddOrifice(plenumInlet, pipeIndex: 0, isLeftEnd: false, throttleAreaIdx, 0.7f); // throttle
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boundaries.AddOrifice(plenumOutlet, pipeIndex: 1, isLeftEnd: true, plenumRunnerAreaIdx, 1.0f); // plenum→runner
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boundaries.AddOrifice(cylinder.IntakePort, pipeIndex: 1, isLeftEnd: false, intakeValveIdx, 1.0f); // intake valve
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boundaries.AddOrifice(cylinder.ExhaustPort, pipeIndex: 2, isLeftEnd: true, exhaustValveIdx, 1.0f); // exhaust valve
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orificeAreas = new float[4];
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orificeAreas[plenumRunnerAreaIdx] = intakePipeArea; // runner cross‑section (fixed)
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// ---- Solver ----
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solver = new Solver { SubStepCount = 4, 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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solver.AddComponent(exhaustCollector);
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// ---- Sound ----
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exhaustSound = new SoundProcessor(sampleRate, 1f) { Gain = 10f };
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intakeSound = new SoundProcessor(sampleRate, 1f) { Gain = 10f };
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reverb = new OutdoorExhaustReverb(sampleRate);
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stepCount = 0;
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Console.WriteLine("CRF250R engine ready.");
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}
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public override float Process()
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{
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// Manual brake torque (0..30 Nm)
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float loadTorque = Load * MaxBrakeTorque;
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crankshaft.SetLoadTorque(loadTorque);
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crankshaft.Step((float)dt);
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cylinder.PreStep((float)dt);
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float throttledArea = _maxThrottleArea * Math.Clamp(Throttle, 0.001f, 1f);
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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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solver.Step();
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stepCount++;
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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 % 1000 == 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 + cylinder.PhaseOffset) * 180f / MathF.PI % 720f;
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Console.WriteLine($"Step {stepCount}, CA={crankDeg:F1}°, RPM={rpm:F0}, CylP={cylinder.Pressure/1e5f:F2} bar");
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Console.WriteLine($" intake flow: {intakeFlow:F6}, exhaust flow: {exhaustFlow:F6}");
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var (r0L, u0L, p0L) = pipeSystem.GetInteriorStateLeft(0);
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var (r0R, u0R, p0R) = pipeSystem.GetInteriorStateRight(0);
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Console.WriteLine($" Pipe0 L: rho={r0L:F4} u={u0L:F3} p={p0L/1e5:F3}bar | R: rho={r0R:F4} u={u0R:F3} p={p0R/1e5:F3}bar");
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var (r1L, u1L, p1L) = pipeSystem.GetInteriorStateLeft(1);
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var (r1R, u1R, p1R) = pipeSystem.GetInteriorStateRight(1);
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Console.WriteLine($" 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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var (r2L, u2L, p2L) = pipeSystem.GetInteriorStateLeft(2);
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var (r2R, u2R, p2R) = pipeSystem.GetInteriorStateRight(2);
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Console.WriteLine($" Pipe2 L: rho={r2L:F4} u={u2L:F3} p={p2L/1e5:F3}bar | R: rho={r2R:F4} u={u2R:F3} p={p2R/1e5:F3}bar");
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Console.WriteLine($" 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) * 0.5f);
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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 openEndX = 40f;
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float pipe1StartX = openEndX;
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float pipe1EndX = pipe1StartX + 120f;
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DrawPipe(target, pipeSystem, 0, intakeY, pipe1StartX, pipe1EndX);
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float throttleX = pipe1EndX + 5f;
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var throttleRect = new RectangleShape(new Vector2f(8f, 30f))
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{
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FillColor = Color.Yellow,
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Position = new Vector2f(throttleX, intakeY - 15f)
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};
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target.Draw(throttleRect);
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float plenW = 60f, plenH = 80f;
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float plenLeftX = throttleX + 10f;
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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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float runnerStartX = plenLeftX + plenW + 5f;
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float runnerEndX = runnerStartX + 100f;
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DrawPipe(target, pipeSystem, 1, intakeY, runnerStartX, runnerEndX);
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float cylCX = runnerEndX + 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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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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// --- RPM & Power labels ---
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float rpm = crankshaft.AngularVelocity * 60f / (2f * MathF.PI);
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float powerKw = crankshaft.AveragePower * 1e-3f;
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DrawLabel(target, $"RPM: {rpm:F0}", new Vector2f(20, 90), Color.White, 24);
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DrawLabel(target, $"Power: {powerKw:F2} kW", new Vector2f(20, 115), Color.White, 24);
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// --- Dyno curve ---
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float torqueNm = crankshaft.AverageTorque;
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UpdateDynoCurve(rpm, powerKw, torqueNm);
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float graphX = winW - 410f;
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float graphY = winH - 260f;
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float graphW = 400f;
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float graphH = 250f;
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DrawDynoCurve(target, graphX, graphY, graphW, graphH, rpm, powerKw);
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}
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}
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} |