Merge branch 'inertia-smaller-engines' into 'amdm2/develop'

fix #189: reconsider inertia for smaller engines

See merge request vecto/vecto!133

VectoCore/VectoCore/Models/Declaration/DeclarationData.cs

@@ -823,13 +823,52 @@ namespace TUGraz.VectoCore.Models.Declaration
 			public static readonly KilogramSquareMeter TorqueConverterInertia = 1.2.SI<KilogramSquareMeter>();
 
 			public static readonly KilogramSquareMeter EngineBaseInertia = 0.41.SI<KilogramSquareMeter>();
-			public static readonly KilogramPerMeter EngineDisplacementInertia = (0.27 * 1000).SI<KilogramPerMeter>(); // [kg/m]
+			public static readonly KilogramPerMeter EngineDisplacementInertia = 270.SI<KilogramPerMeter>();
 			public static readonly Second DefaultEngineStartTime = 1.SI<Second>();
 
 			public const double TorqueLimitGearboxFactor = 0.9;
 			public const double TorqueLimitVehicleFactor = 0.95;
 
+			public static readonly SI SmallEnginesBound = 3.2.SI<Liter>().Cast<CubicMeter>();
+			public static readonly SI MidEnginesBound = 5.SI<Liter>().Cast<CubicMeter>();
+
+			public static readonly KilogramSquareMeter ManualBaseInertia = 1.885.SI<KilogramSquareMeter>();
+			public static readonly KilogramSquareMeter ATBaseInertia = 1.707.SI<KilogramSquareMeter>();
+
+			public static readonly KilogramPerMeter SmallEngineDisplacementInertia = 400.SI<KilogramPerMeter>();
+			public static readonly KilogramPerMeter MidEngineATDisplacementInertia = 933.SI<KilogramPerMeter>();
+			public static readonly KilogramPerMeter MidEngineManualDisplacementInertia = 989.SI<KilogramPerMeter>();
+
 			public static KilogramSquareMeter EngineInertia(VectoSimulationJobType jobType, CubicMeter displacement, GearboxType? gbxType)
+			{
+				if (displacement <= SmallEnginesBound) {
+					return ComputeSmallEngineInertia(displacement);
+				}
+				else if ((displacement > SmallEnginesBound) && (displacement <= MidEnginesBound)) {
+					return ComputeMidEngineInertia(displacement, gbxType);
+				}
+				else {
+					return ComputeBigEngineInertia(jobType, displacement, gbxType);
+				}
+			}
+
+			private static KilogramSquareMeter ComputeSmallEngineInertia(CubicMeter displacement)
+			{ 
+				return (SmallEngineDisplacementInertia * displacement).Cast<KilogramSquareMeter>();
+			}
+
+			private static KilogramSquareMeter ComputeMidEngineInertia(CubicMeter displacement, GearboxType? gbxType)
+			{ 
+				if (!gbxType.HasValue) {
+					throw new VectoException("Gearbox type must be provided!");
+				}
+
+				return gbxType.Value.AutomaticTransmission()
+					? (MidEngineATDisplacementInertia * displacement) - ATBaseInertia
+					: (MidEngineManualDisplacementInertia * displacement) - ManualBaseInertia;
+			}
+
+			private static KilogramSquareMeter ComputeBigEngineInertia(VectoSimulationJobType jobType, CubicMeter displacement, GearboxType? gbxType)
 			{
 				// VB Code:    Return 1.3 + 0.41 + 0.27 * (Displ / 1000)
 				KilogramSquareMeter clutchPlateTc;

VectoCore/VectoCoreTest/Models/Declaration/DeclarationDataTest.cs

@@ -79,6 +79,27 @@ namespace TUGraz.VectoCore.Tests.Models.Declaration
 			_kernel = new StandardKernel(new VectoNinjectModule());
         }
 
+        [
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.002, null, 0.8),
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.0032, null, 1.28),
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.0033, GearboxType.ATPowerSplit, 1.3719),
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.0033, GearboxType.MT, 1.3787),
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.005, GearboxType.MT, 3.06),
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.006, GearboxType.MT, 3.33),
+        TestCase(VectoSimulationJobType.ConventionalVehicle, 0.006, GearboxType.ATPowerSplit, 3.23),
+        TestCase(VectoSimulationJobType.SerialHybridVehicle, 0.006, null, 2.03)
+        ]
+        public void EngineInertiaTest(VectoSimulationJobType jobType, double displacement, GearboxType? gbxType,
+            double inertia)
+        { 
+            KilogramSquareMeter result = DeclarationData.Engine.EngineInertia(
+                jobType, 
+                displacement.SI<CubicMeter>(), 
+                gbxType);
+            
+            Assert.AreEqual(inertia, result.Value(), 1e-4);
+        }
+
 
         [TestCase("285/60 R22.5", 10.6, 0.914, 3.03, 0.440766),
 		TestCase("285/70 R19.5", 7.9, 0.895, 3.05, 0.434453),