Add turbocharged twin scenario and cross-platform test harness

2026-10-23 02:27:03 +02:00
parent a859740a95
commit 589d22aa5e
63 changed files with 4903 additions and 771 deletions
--- a/include/FluidSim/Turbocharger.hpp
+++ b/include/FluidSim/Turbocharger.hpp
@@ -0,0 +1,78 @@
+#pragma once
+
+#include "FluidSim/Fluid.hpp"
+#include <array>
+#include <cstdint>
+
+namespace fluidsim::port {
+
+// RHB31/VZ21-size mean-line approximation. Geometry, losses and coefficients
+// are estimates, not a digitized or validated manufacturer performance map.
+struct TurboConfig {
+    double shaft_inertia{4e-6}; // kg m^2, compressor+turbine+shaft rigid rotor
+    double compressor_radius{.018}, turbine_radius{.0135};
+    double compressor_head_coefficient{.60}, compressor_efficiency{.65};
+    double turbine_peak_efficiency{.65}, turbine_optimum_speed_ratio{.70};
+    double compressor_effective_area{110e-6}, turbine_effective_area{100e-6};
+    double bearing_viscous{1e-7}, windage{2e-11}; // Nm/(rad/s), Nm/(rad/s)^2
+    // Estimated pressure-can/spring wastegate. Set maximum lift to zero for a
+    // pure ungated turbo bench test. This changes bypass AREA, never boost.
+    double gate_diaphragm_area{8e-4}, gate_spring_preload{40}, gate_spring_stiffness{6000};
+    double gate_damping{120}, gate_diameter{.014}, gate_maximum_lift{.004};
+    double reference_pressure{101325};
+    float compressor_inlet_volume{20e-6f}, compressor_outlet_volume{30e-6f};
+    float turbine_inlet_volume{30e-6f}, turbine_outlet_volume{20e-6f};
+    std::array<float, 4> connection_diameters{.024f, .024f, .025f, .026f};
+};
+
+struct TurboSnapshot {
+    double rpm{}, angle{}, shaft_energy{}, turbine_power{}, compressor_power{}, bearing_power{};
+    double compressor_flow{}, turbine_flow{}, compressor_pressure_ratio{}, turbine_pressure_ratio{};
+    double turbine_inlet_pressure{}, turbine_outlet_pressure{}, charge_pressure{}, charge_temperature{};
+    double bearing_heat{}, energy_residual{};
+    std::uint64_t limited_transfers{};
+    double wastegate_flow{}, wastegate_lift{};
+};
+
+// Four pressure-storage nodes joined by turbine/nozzle and centrifugal-pump
+// characteristics. Existing pipe orifices exchange conserved mass/enthalpy.
+// The whole turbo is ONE solver component; do not also register its volumes.
+class Turbocharger final : public Component {
+public:
+    explicit Turbocharger(TurboConfig config = {});
+    const TurboConfig config;
+    Volume0D compressor_inlet, compressor_outlet, turbine_inlet, turbine_outlet;
+    Port& compressor_inlet_port;
+    Port& compressor_outlet_port;
+    Port& turbine_inlet_port;
+    Port& turbine_outlet_port;
+
+    void connect(BoundarySystem& boundaries, const std::vector<Pipe1D>& pipes,
+                 int compressor_in, bool compressor_in_left, int compressor_out, bool compressor_out_left,
+                 int turbine_in, bool turbine_in_left, int turbine_out, bool turbine_out_left);
+    std::vector<Port*> ports() override;
+    void update_state(float dt) override;
+    TurboSnapshot snapshot() const;
+    double omega() const { return omega_; }
+    double shaft_energy() const { return .5*config.shaft_inertia*omega_*omega_; }
+    double fluid_energy() const;
+    // Intended for standalone initialization/tests, never an imposed running speed.
+    void set_initial_rpm(double rpm);
+
+private:
+    std::array<Port*, 4> internal_;
+    std::array<float, 4> connection_areas_{};
+    double omega_{}, angle_{}, bearing_heat_{};
+    double turbine_power_{}, compressor_power_{}, bearing_power_{}, energy_residual_{};
+    double compressor_flow_{}, turbine_flow_{};
+    double wastegate_flow_{}, wastegate_lift_{};
+    std::uint64_t limited_transfers_{};
+    bool connected_{};
+    static double nozzle(double upstream_pressure, double upstream_temperature,
+                         double downstream_pressure, double area);
+    double transfer_flow(Volume0D& inlet, Volume0D& outlet, Port& inlet_external,
+                         Port& outlet_external, double requested, double dt);
+    static void set_transfer(Volume0D& inlet, Volume0D& outlet, Port& inlet_internal,
+                             Port& outlet_internal, double flow, double shaft_work, double dt);
+};
+} // namespace fluidsim::port