rusefi/unit_tests/tests/test_throttle_model.cpp

#include "pch.h"
#include "throttle_model.h"

// From CFD modeled 70mm throttle
static const float throttle70mmFlowBins[] =   {        2,     5,      10,    20,    30,    40,    60,   80,   85,    90,    91 };
static const float throttle70mmFlowValues[] = { 0.000095, 0.002,  0.0107, 0.045, 0.103, 0.185, 0.438, 0.74, 0.77, 0.775, 0.775 };

class MockThrottleModel : public ThrottleModelBase {
public:
	float effectiveArea(float tps) const override {
		return interpolate2d(tps, throttle70mmFlowBins, throttle70mmFlowValues);
	}

	MOCK_METHOD(float, maxEngineFlow, (float map), (const, override));
};

TEST(ThrottleModel, PartThrottle) {
	MockThrottleModel model;

	EXPECT_CALL(model, maxEngineFlow(::testing::_)).WillRepeatedly([](float map) { return map / 100 * 0.5f; });

	// Vary throttle at constant PR/temp
	// 100kPa inlet
	// 45 kPa MAP
	// 0C IAT
	EXPECT_NEAR(0.01056, model.estimateThrottleFlow(100, 10, 45, 0), 1e-4);
	EXPECT_NEAR(0.04441, model.estimateThrottleFlow(100, 20, 45, 0), 1e-4);
	EXPECT_NEAR(0.10165, model.estimateThrottleFlow(100, 30, 45, 0), 1e-4);
	EXPECT_NEAR(0.18258, model.estimateThrottleFlow(100, 40, 45, 0), 1e-4);

	// Vary inlet pressure
	EXPECT_NEAR(1.0 * 0.04441, model.estimateThrottleFlow(100, 20, 45, 0), 1e-4);
	EXPECT_NEAR(1.5 * 0.04441, model.estimateThrottleFlow(150, 20, 45, 0), 1e-4);
}

TEST(ThrottleModel, InverseFlowLowPressureRatio) {
	MockThrottleModel model;

	EXPECT_NEAR( 2.329, model.throttlePositionForFlow(0.0003, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR( 3.446, model.throttlePositionForFlow(0.001, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR( 9.674, model.throttlePositionForFlow(0.010, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(29.711, model.throttlePositionForFlow(0.100, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(41.395, model.throttlePositionForFlow(0.200, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(57.415, model.throttlePositionForFlow(0.400, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(71.255, model.throttlePositionForFlow(0.600, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(77.965, model.throttlePositionForFlow(0.700, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(83.323, model.throttlePositionForFlow(0.750, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(85.070, model.throttlePositionForFlow(0.760, 0.3, 100, 0), 1e-2);

	// Throttle is maxed out here!

	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.770, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.800, 0.3, 100, 0), 1e-2);
	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.900, 0.3, 100, 0), 1e-2);
}

TEST(ThrottleModel, InverseFlowHighPressureRatio) {
	MockThrottleModel model;

	EXPECT_NEAR( 2.626, model.throttlePositionForFlow(0.0003, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR( 4.437, model.throttlePositionForFlow(0.001, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR( 5.738, model.throttlePositionForFlow(0.002, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR( 8.571, model.throttlePositionForFlow(0.005, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(11.670, model.throttlePositionForFlow(0.010, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(37.473, model.throttlePositionForFlow(0.100, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(51.348, model.throttlePositionForFlow(0.200, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(74.510, model.throttlePositionForFlow(0.400, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(87.093, model.throttlePositionForFlow(0.470, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(88.737, model.throttlePositionForFlow(0.471, 0.9, 100, 0), 1e-2);

	// Throttle is maxed out here!

	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.473, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.500, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.600, 0.9, 100, 0), 1e-2);
	EXPECT_NEAR(100.00, model.throttlePositionForFlow(0.700, 0.9, 100, 0), 1e-2);
}

TEST(ThrottleModel, SmallEngineBigThrottle) {
	MockThrottleModel model;

	// Engine can only flow 0.2kg/s at 100kPa, much less than wide open throttle
	EXPECT_CALL(model, maxEngineFlow(::testing::_)).WillRepeatedly([](float map) { return map / 100 * 0.2f; });

	// v   part throttle model   v
	EXPECT_NEAR(0.082f, model.estimateThrottleFlow(100,  40, 95, 0), 1e-3);
	EXPECT_NEAR(0.138f, model.estimateThrottleFlow(100,  50, 95, 0), 1e-3);
	// ^   part throttle model   ^

	// this engine does 0.95PR at 59% throttle, as the throttle is very big for the engine

	// v   blend from part throttle to WOT   v
	EXPECT_NEAR(0.190f, model.estimateThrottleFlow(100,  60, 95, 0), 1e-3);
	EXPECT_NEAR(0.193f, model.estimateThrottleFlow(100,  70, 95, 0), 1e-3);
	EXPECT_NEAR(0.195f, model.estimateThrottleFlow(100,  80, 95, 0), 1e-3);
	EXPECT_NEAR(0.198f, model.estimateThrottleFlow(100,  90, 95, 0), 1e-3);
	// ^   blend from part throttle to WOT   ^

	// v   WOT   v
	EXPECT_NEAR(0.20f, model.estimateThrottleFlow(100, 100, 95, 0), 1e-3);
}

TEST(ThrottleModel, BigEngineSmallThrottle) {
	MockThrottleModel model;

	// Big engine can flow 2g/s, much more than wide open throttle will support
	EXPECT_CALL(model, maxEngineFlow(::testing::_)).WillRepeatedly([](float map) { return map / 100 * 2; });

	// v   part throttle model   v
	EXPECT_NEAR(0.082f, model.estimateThrottleFlow(100,  40, 95, 0), 1e-3);
	EXPECT_NEAR(0.138f, model.estimateThrottleFlow(100,  50, 95, 0), 1e-3);
	EXPECT_NEAR(0.194f, model.estimateThrottleFlow(100,  60, 95, 0), 1e-3);
	EXPECT_NEAR(0.261f, model.estimateThrottleFlow(100,  70, 95, 0), 1e-3);
	EXPECT_NEAR(0.327f, model.estimateThrottleFlow(100,  80, 95, 0), 1e-3);
	EXPECT_NEAR(0.343f, model.estimateThrottleFlow(100,  90, 95, 0), 1e-3);
	EXPECT_NEAR(0.343f, model.estimateThrottleFlow(100, 100, 95, 0), 1e-3);
	// ^   part throttle model   ^
}