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added 4 cyl

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This commit is contained in:
max
2026-05-08 00:38:26 +02:00
parent b7a40217db
commit f275937abb
7 changed files with 374 additions and 66 deletions
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38
Components/Cylinder.cs
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@@ -46,9 +46,7 @@ namespace FluidSim.Components
public double FuelLowerHeatingValue { get; set; } = 44e6;
// Cycle‑to‑cycle randomness
/// <summary>Fractional variation in fuel energy (±). 0.05 = ±5%.</summary>
public double EnergyVariationFraction { get; set; } = 0.05;
/// <summary>Probability of a misfire (0‑1).</summary>
public double MisfireProbability { get; set; } = 0.01;
// Heat loss
@@ -56,7 +54,14 @@ namespace FluidSim.Components
public double HeatTransferCoefficient { get; set; } = 100.0;
public double AmbientTemperature { get; set; } = 300.0;
// State
// ---- Multi‑cylinder support ----
/// <summary>
/// Phase offset (radians) added to the crankshaft angle for this cylinder.
/// Used for multi‑cylinder engines; set to 0 for single‑cylinder.
/// </summary>
public double PhaseOffset { get; set; } = 0.0;
// State (public for drawing)
public double Volume => cylinderVolume;
public double Pressure => (Gamma - 1.0) * cylinderEnergy / Math.Max(cylinderVolume, 1e-12);
public double Temperature => Pressure / Math.Max(Density * GasConstant, 1e-12);
@@ -75,8 +80,7 @@ namespace FluidSim.Components
private bool combustionActive;
private bool fuelInjected;
// per‑cycle randomness
private double _energyFactor = 1.0; // applied to FuelLowerHeatingValue this cycle
private double _energyFactor = 1.0;
private readonly Random _random = new Random();
private const double Gamma = 1.4;
@@ -115,7 +119,10 @@ namespace FluidSim.Components
private double clearanceVolume => SweptVolume / (CompressionRatio - 1.0);
private double CrankRadius => Stroke / 2.0;
private double Obliquity => CrankRadius / ConRodLength;
private double CrankDeg => (Crankshaft.CrankAngle % (4.0 * Math.PI)) * 180.0 / Math.PI % 720.0;
// Offset-aware crank angle in degrees
private double CrankDeg =>
((Crankshaft.CrankAngle + PhaseOffset) % (4.0 * Math.PI)) * 180.0 / Math.PI % 720.0;
public double ComputeVolume(double thetaRad)
{
@@ -174,7 +181,9 @@ namespace FluidSim.Components
public void PreStep(double dt)
{
double prevVolume = cylinderVolume;
double crankAngleRad = Crankshaft.CrankAngle;
// ----- Use phase‑offset crank angle for this cylinder -----
double crankAngleRad = Crankshaft.CrankAngle + PhaseOffset;
cylinderVolume = ComputeVolume(crankAngleRad);
double dV = cylinderVolume - prevVolume;
@@ -191,7 +200,9 @@ namespace FluidSim.Components
cylinderEnergy -= Pressure * dV;
double prevDeg = Crankshaft.PreviousAngle * 180.0 / Math.PI % 720.0;
// Also use offset angle for event detection
double crankshaftPrevAngle = Crankshaft.PreviousAngle;
double prevDeg = (crankshaftPrevAngle + PhaseOffset) * 180.0 / Math.PI % 720.0;
double currDeg = crankAngleRad * 180.0 / Math.PI % 720.0;
// ----- Intake closing: capture trapped air mass and compute fuel -----
@@ -202,7 +213,7 @@ namespace FluidSim.Components
fuelInjected = true;
}
// ----- Spark ignition (once per cycle, with misfire chance) -----
// ----- Spark ignition -----
double sparkAngle = 0.0 - SparkAdvance;
if (sparkAngle < 0) sparkAngle += 720.0;
@@ -210,19 +221,15 @@ namespace FluidSim.Components
(prevDeg > sparkAngle + 360.0 && currDeg < sparkAngle);
if (crossedSpark && !combustionActive && fuelInjected)
{
// Decide misfire
bool misfire = _random.NextDouble() < MisfireProbability;
if (misfire)
{
combustionActive = false; // no combustion this cycle
// fuel is not burned – will remain in cylinder and eventually exit as unburned mixture
combustionActive = false;
}
else
{
combustionActive = true;
burnFraction = 0.0;
// Energy variation factor for this cycle
double range = EnergyVariationFraction;
_energyFactor = 1.0 + range * (2.0 * _random.NextDouble() - 1.0);
}
@@ -239,7 +246,6 @@ namespace FluidSim.Components
{
newFraction = 1.0;
combustionActive = false;
// All gas becomes exhaust
double totalMass = _airMass + _exhaustMass;
_airMass = 0.0;
_exhaustMass = totalMass;
@@ -255,7 +261,7 @@ namespace FluidSim.Components
}
}
// ----- Heat loss to cylinder walls -----
// ----- Heat loss -----
double dQ_loss = HeatTransferCoefficient * CylinderWallArea *
(Temperature - AmbientTemperature) * dt;
cylinderEnergy -= dQ_loss;

1
Components/Pipe1D.cs
View File

@@ -18,6 +18,7 @@ namespace FluidSim.Components
public double Area { get; }
public double DampingMultiplier { get; set; } = 10.0;
public double EnergyRelaxationRate { get; set; } = 5.0; // 1/s
public string Name = "Pipe";
private double _ambientPressure = 101325.0;
public double AmbientPressure

80
Core/Solver.cs
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@@ -20,17 +20,11 @@ namespace FluidSim.Core
// ---------- Timing accumulators (reset every LogInterval steps) ----------
private long _stepCount;
private double _timeTotal;
private double _timeCFL;
private double _timeOrifice;
private double _timeOpenEnd;
private double _timeJunction;
private double _timePipe;
private double _timeClearGhosts;
private double _timeUpdateState;
private double _timeTotal, _timeCFL, _timeOrifice, _timeOpenEnd,
_timePipe, _timeClearGhosts, _timeUpdateState;
private const int LogInterval = 5000; // print once per second (at 44.1 kHz)
private const bool EnableLogging = false;
private const int LogInterval = 5000;
private const bool EnableLogging = false; // temporarily ON for debugging
public void SetTimeStep(double dt) => _dt = dt;
@@ -45,18 +39,44 @@ namespace FluidSim.Core
var sw = Stopwatch.StartNew();
// CFL count
// CFL count – track which pipe demands the most sub‑steps
int nSub = 1;
Pipe1D worstPipe = pipes[0];
foreach (var p in pipes)
nSub = Math.Max(nSub, p.GetRequiredSubSteps(_dt, CflTarget));
{
int n = p.GetRequiredSubSteps(_dt, CflTarget);
if (n > nSub)
{
nSub = n;
worstPipe = p;
}
}
double dtSub = _dt / nSub;
// ----- Diagnostic: warn if nSub is high -----
if (nSub > 50)
{
double maxW = 0;
for (int i = 0; i < worstPipe.CellCount; i++)
{
double rho = worstPipe.GetCellDensity(i);
double u = Math.Abs(worstPipe.GetCellVelocity(i));
double p = worstPipe.GetCellPressure(i);
double c = Math.Sqrt(1.4 * p / Math.Max(rho, 1e-12));
if (u + c > maxW) maxW = u + c;
}
Console.WriteLine($"nSub = {nSub} (worst pipe: {worstPipe.Name}, maxW = {maxW:F0} m/s)");
}
_timeCFL += sw.Elapsed.TotalSeconds;
// ----- Safety cap – prevent the solver from hanging -----
const int maxSubSteps = 10000;
if (nSub > maxSubSteps)
const int hardLimit = 500; // temporary low cap for debugging
if (nSub > hardLimit)
{
Console.WriteLine($"Warning: required sub‑steps {nSub} exceeds limit. Simulation stopped.");
Console.WriteLine($"nSub ({nSub}) exceeds hard limit {hardLimit}. Simulation step skipped.");
return;
}
@@ -90,49 +110,33 @@ namespace FluidSim.Core
comp.UpdateState(_dt);
_timeUpdateState += sw.Elapsed.TotalSeconds - tUS;
// accumulate total step time (includes CFL, sub‑steps, clear ghosts, update state)
_timeTotal += sw.Elapsed.TotalSeconds;
// ---------- Periodic report ----------
_stepCount++;
if (_stepCount % LogInterval == 0 && EnableLogging)
{
if (_timeTotal > 0)
{
double totalMs = _timeTotal * 1000.0;
double avgUs = (_timeTotal / LogInterval) * 1e6; // µs per step
double stepsPerSec = LogInterval / _timeTotal; // steps per second
double stepsPerSec = LogInterval / _timeTotal;
double avgUs = (_timeTotal / LogInterval) * 1e6;
Console.WriteLine($"--- Solver timing ({LogInterval} steps) ---");
Console.WriteLine($" Steps per second: {stepsPerSec:F1}");
Console.WriteLine($" Avg step time: {avgUs:F1} µs (last nSub = {nSub})");
Console.WriteLine($" CFL calc: {_timeCFL / _timeTotal * 100:F1} % ({_timeCFL * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" CFL calc: {_timeCFL / _timeTotal * 100:F1} %");
Console.WriteLine($" Sub‑step loop:");
Console.WriteLine($" Orifice: {_timeOrifice / _timeTotal * 100:F1} % ({_timeOrifice * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" OpenEnd: {_timeOpenEnd / _timeTotal * 100:F1} % ({_timeOpenEnd * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" Junctions: {_timeJunction / _timeTotal * 100:F1} % ({_timeJunction * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" Pipe steps: {_timePipe / _timeTotal * 100:F1} % ({_timePipe * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" Clear ghosts: {_timeClearGhosts / _timeTotal * 100:F1} % ({_timeClearGhosts * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" Update state: {_timeUpdateState / _timeTotal * 100:F1} % ({_timeUpdateState * 1e6 / LogInterval:F1} µs/step)");
Console.WriteLine($" Orifice: {_timeOrifice / _timeTotal * 100:F1} %");
Console.WriteLine($" OpenEnd: {_timeOpenEnd / _timeTotal * 100:F1} %");
Console.WriteLine($" Pipe steps: {_timePipe / _timeTotal * 100:F1} %");
Console.WriteLine($" Clear ghosts: {_timeClearGhosts / _timeTotal * 100:F1} %");
Console.WriteLine($" Update state: {_timeUpdateState / _timeTotal * 100:F1} %");
Console.WriteLine();
// ---------- Optional detailed pipe profiling ----------
if (Pipe1D.EnableDetailedProfiling)
{
foreach (var pipe in pipes)
{
Console.WriteLine(pipe.GetDetailProfileReport());
pipe.ResetDetailCounters();
}
}
}
// Reset accumulators for next interval
_timeTotal = 0;
_timeCFL = 0;
_timeOrifice = 0;
_timeOpenEnd = 0;
_timeJunction = 0;
_timePipe = 0;
_timeClearGhosts = 0;
_timeUpdateState = 0;

12
Program.cs
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@@ -33,7 +33,7 @@ public class Program
// Audio & simulation
private static SimulationRingBuffer _simRingBuffer = null!;
private static SoundEngine _soundEngine = null!;
private static TestScenario _scenario = null!; // cast to access ThrottleArea
private static Scenario _scenario = null!; // cast to access ThrottleArea
private static Font? _overlayFont;
private static Text? _overlayText;
@@ -50,7 +50,8 @@ public class Program
{
var window = CreateWindow();
LoadFont();
_scenario = (TestScenario)InitializeScenario();
_scenario = new TestScenario();
_scenario.Initialize(SampleRate);
_lastThrottleUpdateTime = 0.0;
_simRingBuffer = new SimulationRingBuffer(131072);
@@ -170,13 +171,6 @@ public class Program
};
}
private static Scenario InitializeScenario()
{
var sc = new TestScenario();
sc.Initialize(SampleRate);
return sc;
}
private static void OnMouseWheel(object? sender, MouseWheelScrollEventArgs e)
{
if (_timeWarpActive) return;

303
Scenarios/Inline4Scenario.cs Normal file
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@@ -0,0 +1,303 @@
using System;
using SFML.Graphics;
using SFML.System;
using FluidSim.Components;
using FluidSim.Core;
using FluidSim.Utils;
namespace FluidSim.Tests
{
public class Inline4Scenario : Scenario
{
// Crankshaft
private Crankshaft crankshaft;
// Cylinders
private Cylinder cyl1, cyl2, cyl3, cyl4;
// Intake
private Pipe1D intakePipeBeforeThrottle;
private Volume0D intakePlenum;
// Runners
private Pipe1D runner1, runner2, runner3, runner4;
// Exhaust pipes
private Pipe1D exh1, exh2, exh3, exh4;
// Links – intake
private OpenEndLink intakeOpenEnd;
private OrificeLink throttleOrifice;
// Plenum‑to‑runner orifices
private OrificeLink plenumToRunner1, plenumToRunner2, plenumToRunner3, plenumToRunner4;
// Intake valves
private OrificeLink intakeValve1, intakeValve2, intakeValve3, intakeValve4;
// Exhaust valves
private OrificeLink exhaustValve1, exhaustValve2, exhaustValve3, exhaustValve4;
// Exhaust open ends
private OpenEndLink exhaustOpenEnd1, exhaustOpenEnd2, exhaustOpenEnd3, exhaustOpenEnd4;
private Solver solver;
private SoundProcessor exhaustSoundProcessor;
private SoundProcessor intakeSoundProcessor;
private OutdoorExhaustReverb reverb;
private double dt;
private int stepCount;
public double MaxThrottleArea { get; set; } = 3 * Units.cm2;
public override void Initialize(int sampleRate)
{
dt = 1.0 / sampleRate;
solver = new Solver();
solver.SetTimeStep(dt);
solver.CflTarget = 0.9;
// ---- Shared crankshaft ----
crankshaft = new Crankshaft(800);
crankshaft.Inertia = 1;
crankshaft.FrictionConstant = 16;
crankshaft.FrictionViscous = 0.5;
// ---- Cylinder geometry ----
double bore = 0.056, stroke = 0.057, conRod = 0.110, compRatio = 9.2;
double ivo = 350.0, ivc = 580.0, evo = 120.0, evc = 370.0;
// Firing order 1-3-4-2 → phase offsets in radians
double phase0 = 0.0 * Math.PI / 180.0;
double phase1 = 180.0 * Math.PI / 180.0;
double phase2 = 540.0 * Math.PI / 180.0;
double phase3 = 360.0 * Math.PI / 180.0;
cyl1 = new Cylinder(bore, stroke, conRod, compRatio, ivo, ivc, evo, evc, crankshaft)
{
IntakeValveDiameter = 30 * Units.mm,
IntakeValveLift = 5 * Units.mm,
ExhaustValveDiameter = 28 * Units.mm,
ExhaustValveLift = 5 * Units.mm,
PhaseOffset = phase0,
EnergyVariationFraction = 0.03,
MisfireProbability = 0.01
};
cyl2 = new Cylinder(bore, stroke, conRod, compRatio, ivo, ivc, evo, evc, crankshaft)
{
IntakeValveDiameter = 30 * Units.mm,
IntakeValveLift = 5 * Units.mm,
ExhaustValveDiameter = 28 * Units.mm,
ExhaustValveLift = 5 * Units.mm,
PhaseOffset = phase1,
EnergyVariationFraction = 0.03,
MisfireProbability = 0.01
};
cyl3 = new Cylinder(bore, stroke, conRod, compRatio, ivo, ivc, evo, evc, crankshaft)
{
IntakeValveDiameter = 30 * Units.mm,
IntakeValveLift = 5 * Units.mm,
ExhaustValveDiameter = 28 * Units.mm,
ExhaustValveLift = 5 * Units.mm,
PhaseOffset = phase2,
EnergyVariationFraction = 0.03,
MisfireProbability = 0.01
};
cyl4 = new Cylinder(bore, stroke, conRod, compRatio, ivo, ivc, evo, evc, crankshaft)
{
IntakeValveDiameter = 30 * Units.mm,
IntakeValveLift = 5 * Units.mm,
ExhaustValveDiameter = 28 * Units.mm,
ExhaustValveLift = 5 * Units.mm,
PhaseOffset = phase3,
EnergyVariationFraction = 0.03,
MisfireProbability = 0.01
};
solver.AddComponent(cyl1);
solver.AddComponent(cyl2);
solver.AddComponent(cyl3);
solver.AddComponent(cyl4);
double pipeDiameter = 2 * Units.cm;
double pipeArea = Units.AreaFromDiameter(pipeDiameter);
exhaustSoundProcessor = new SoundProcessor(sampleRate, 1, pipeDiameter) { Gain = 0.1f };
intakeSoundProcessor = new SoundProcessor(sampleRate, 1, pipeDiameter) { Gain = 0.1f };
reverb = new OutdoorExhaustReverb(sampleRate);
// ---- Intake pipe before throttle ----
intakePipeBeforeThrottle = new Pipe1D(0.2, pipeArea, 10);
solver.AddComponent(intakePipeBeforeThrottle);
// ---- Plenum ----
intakePlenum = new Volume0D(50 * Units.mL, 101325.0, 300.0);
var plenumInlet = intakePlenum.CreatePort(); // port 0
var plenumOut1 = intakePlenum.CreatePort(); // port 1
var plenumOut2 = intakePlenum.CreatePort(); // port 2
var plenumOut3 = intakePlenum.CreatePort(); // port 3
var plenumOut4 = intakePlenum.CreatePort(); // port 4
solver.AddComponent(intakePlenum);
// ---- Runners ----
runner1 = new Pipe1D(0.2, pipeArea, 5);
runner2 = new Pipe1D(0.2, pipeArea, 5);
runner3 = new Pipe1D(0.2, pipeArea, 5);
runner4 = new Pipe1D(0.2, pipeArea, 5);
solver.AddComponent(runner1);
solver.AddComponent(runner2);
solver.AddComponent(runner3);
solver.AddComponent(runner4);
// ---- Exhaust pipes ----
exh1 = new Pipe1D(0.2, pipeArea, 10);
exh2 = new Pipe1D(0.2, pipeArea, 10);
exh3 = new Pipe1D(0.2, pipeArea, 10);
exh4 = new Pipe1D(0.2, pipeArea, 10);
solver.AddComponent(exh1);
solver.AddComponent(exh2);
solver.AddComponent(exh3);
solver.AddComponent(exh4);
// ---- Plenum → runner orifices ----
plenumToRunner1 = new OrificeLink(plenumOut1, runner1, isPipeLeftEnd: true, areaProvider: () => pipeArea) { DischargeCoefficient = 1.0, UseInertance = false };
plenumToRunner2 = new OrificeLink(plenumOut2, runner2, isPipeLeftEnd: true, areaProvider: () => pipeArea) { DischargeCoefficient = 1.0, UseInertance = false };
plenumToRunner3 = new OrificeLink(plenumOut3, runner3, isPipeLeftEnd: true, areaProvider: () => pipeArea) { DischargeCoefficient = 1.0, UseInertance = false };
plenumToRunner4 = new OrificeLink(plenumOut4, runner4, isPipeLeftEnd: true, areaProvider: () => pipeArea) { DischargeCoefficient = 1.0, UseInertance = false };
solver.AddOrificeLink(plenumToRunner1);
solver.AddOrificeLink(plenumToRunner2);
solver.AddOrificeLink(plenumToRunner3);
solver.AddOrificeLink(plenumToRunner4);
// ---- Intake valves ----
intakeValve1 = new OrificeLink(cyl1.IntakePort, runner1, isPipeLeftEnd: false, areaProvider: () => cyl1.IntakeValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
intakeValve2 = new OrificeLink(cyl2.IntakePort, runner2, isPipeLeftEnd: false, areaProvider: () => cyl2.IntakeValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
intakeValve3 = new OrificeLink(cyl3.IntakePort, runner3, isPipeLeftEnd: false, areaProvider: () => cyl3.IntakeValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
intakeValve4 = new OrificeLink(cyl4.IntakePort, runner4, isPipeLeftEnd: false, areaProvider: () => cyl4.IntakeValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
solver.AddOrificeLink(intakeValve1);
solver.AddOrificeLink(intakeValve2);
solver.AddOrificeLink(intakeValve3);
solver.AddOrificeLink(intakeValve4);
// ---- Exhaust valves ----
exhaustValve1 = new OrificeLink(cyl1.ExhaustPort, exh1, isPipeLeftEnd: true, areaProvider: () => cyl1.ExhaustValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
exhaustValve2 = new OrificeLink(cyl2.ExhaustPort, exh2, isPipeLeftEnd: true, areaProvider: () => cyl2.ExhaustValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
exhaustValve3 = new OrificeLink(cyl3.ExhaustPort, exh3, isPipeLeftEnd: true, areaProvider: () => cyl3.ExhaustValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
exhaustValve4 = new OrificeLink(cyl4.ExhaustPort, exh4, isPipeLeftEnd: true, areaProvider: () => cyl4.ExhaustValveArea) { DischargeCoefficient = 1.0, UseInertance = false };
solver.AddOrificeLink(exhaustValve1);
solver.AddOrificeLink(exhaustValve2);
solver.AddOrificeLink(exhaustValve3);
solver.AddOrificeLink(exhaustValve4);
// ---- Exhaust open ends ----
exhaustOpenEnd1 = new OpenEndLink(exh1, isLeftEnd: false) { AmbientPressure = 101325.0, Gamma = 1.4 };
exhaustOpenEnd2 = new OpenEndLink(exh2, isLeftEnd: false) { AmbientPressure = 101325.0, Gamma = 1.4 };
exhaustOpenEnd3 = new OpenEndLink(exh3, isLeftEnd: false) { AmbientPressure = 101325.0, Gamma = 1.4 };
exhaustOpenEnd4 = new OpenEndLink(exh4, isLeftEnd: false) { AmbientPressure = 101325.0, Gamma = 1.4 };
solver.AddOpenEndLink(exhaustOpenEnd1);
solver.AddOpenEndLink(exhaustOpenEnd2);
solver.AddOpenEndLink(exhaustOpenEnd3);
solver.AddOpenEndLink(exhaustOpenEnd4);
// ---- Intake open end ----
intakeOpenEnd = new OpenEndLink(intakePipeBeforeThrottle, isLeftEnd: true)
{
AmbientPressure = 101325.0,
Gamma = 1.4
};
solver.AddOpenEndLink(intakeOpenEnd);
// ---- Throttle ----
throttleOrifice = new OrificeLink(plenumInlet, intakePipeBeforeThrottle, isPipeLeftEnd: false,
areaProvider: () => MaxThrottleArea * Math.Clamp(Throttle, 0.001, 1.0))
{
DischargeCoefficient = 0.2,
UseInertance = false
};
solver.AddOrificeLink(throttleOrifice);
stepCount = 0;
Console.WriteLine("Inline-4 engine test");
Console.WriteLine($"Bore {bore * 1000:F0}mm, Stroke {stroke * 1000:F0}mm, CR {compRatio}");
Console.WriteLine("Firing order 1-3-4-2, 180° intervals");
}
public override float Process()
{
crankshaft.Step(dt);
cyl1.PreStep(dt);
cyl2.PreStep(dt);
cyl3.PreStep(dt);
cyl4.PreStep(dt);
solver.Step();
stepCount++;
if (stepCount % 10000 == 0)
{
double rpm = crankshaft.AngularVelocity * 60.0 / (2.0 * Math.PI);
Console.WriteLine($"Step {stepCount}, RPM = {rpm:F0}, " +
$"cyl1 P = {cyl1.Pressure / 1e5:F2} bar, " +
$"plenum P = {intakePlenum.Pressure / 1e5:F2} bar");
}
// Mix all exhaust sounds
float exhaustMix = exhaustSoundProcessor.Process(exhaustOpenEnd1)
+ exhaustSoundProcessor.Process(exhaustOpenEnd2)
+ exhaustSoundProcessor.Process(exhaustOpenEnd3)
+ exhaustSoundProcessor.Process(exhaustOpenEnd4);
float intakeDry = intakeSoundProcessor.Process(intakeOpenEnd);
return reverb.Process(exhaustMix * 0.25f + intakeDry);
}
public override void Draw(RenderWindow target)
{
float winW = target.GetView().Size.X;
float winH = target.GetView().Size.Y;
float startX = 60f;
float spacing = 80f;
float intakeY = winH / 2f - 80f;
float exhaustY = winH / 2f + 80f;
// Plenum
float plenW = 50f, plenH = 120f;
float plenX = startX;
float plenTopY = intakeY - plenH / 2f;
DrawVolume(target, intakePlenum, plenX, plenTopY, plenW, plenH);
// Helper arrays just for drawing (no closures)
var cyls = new[] { cyl1, cyl2, cyl3, cyl4 };
var runners = new[] { runner1, runner2, runner3, runner4 };
var exhausts = new[] { exh1, exh2, exh3, exh4 };
for (int i = 0; i < 4; i++)
{
float cylX = plenX + plenW + 30f + i * spacing;
float runnerStartX = plenX + plenW + 5f;
float runnerEndX = cylX - 20f;
DrawPipe(target, runners[i], intakeY, runnerStartX, runnerEndX);
float cylTopY = intakeY - 120f;
DrawCylinder(target, cyls[i], cylX, cylTopY, 70f, 200f);
float exhStartX = cylX + 35f;
float exhEndX = exhStartX + 100f;
DrawPipe(target, exhausts[i], exhaustY, exhStartX, exhEndX);
var mark = new CircleShape(4f) { FillColor = Color.Magenta };
mark.Position = new Vector2f(exhEndX - 4f, exhaustY - 4f);
target.Draw(mark);
}
// Throttle symbol
var throttleRect = new RectangleShape(new Vector2f(6f, 30f))
{
FillColor = Color.Yellow,
Position = new Vector2f(plenX - 16f, intakeY - 15f)
};
target.Draw(throttleRect);
}
}
}

1
Scenarios/Scenario.cs
View File

@@ -13,6 +13,7 @@ namespace FluidSim.Tests
protected const double AmbientPressure = 101325.0;
protected const double AmbientTemperature = 300.0;
public double Throttle { get; set; } = 0.0;
// ---------- Color from pressure (volumes) ----------
protected Color PressureColor(double pressurePa)

5
Scenarios/TestScenario.cs
View File

@@ -37,8 +37,7 @@ namespace FluidSim.Tests
private int stepCount;
// ---------- Throttle control ----------
public double Throttle { get; set; } = 0.0;
public double MaxThrottleArea { get; set; } = 3 * Units.cm2; // 2 cm²
public double MaxThrottleArea { get; set; } = 1 * Units.cm2; // 2 cm²
public override void Initialize(int sampleRate)
{
@@ -50,7 +49,7 @@ namespace FluidSim.Tests
// ---- Crankshaft (external, passed to cylinder) ----
crankshaft = new Crankshaft(600);
crankshaft.Inertia = 0.1;
crankshaft.Inertia = 0.2;
crankshaft.FrictionConstant = 2;
crankshaft.FrictionViscous = 0.04;