"""
@author: F. Ramognino <federico.ramognino@polimi.it>
Last update: 25/06/2024
Generic functions useful for internal combustion engines.
"""
#####################################################################
# IMPORT #
#####################################################################
from __future__ import annotations
import traceback
from libICEpost.src.base.Functions.typeChecking import checkType
from libICEpost.src.base.dataStructures.Dictionary import Dictionary
from .EngineModel.EngineModel import EngineModel
from functools import lru_cache
from libICEpost.GLOBALS import __CACHE_SIZE__
from scipy.interpolate import interp1d
#############################################################################
# MAIN FUNCTIONS #
#############################################################################
[docs]
@lru_cache(__CACHE_SIZE__)
def upMean(*, n:float, S:float) -> float:
"""
Compute the mean piston speed of a piston engine [m/s].
Args:
n (float): Engine speed [rpm]
S (float): Engine stroke [m]
Returns:
float: mean piston speed [m/s]
"""
checkType(n, float, "n")
checkType(S, float, "S")
return 2.*n/60.*S
#############################################################################
[docs]
def MFB(engine:EngineModel, xb:float) -> float:
"""Compute the CA instant at which the engine
model reaches a given fuel mass fraction (xb).
Assuming that the xb array was already computed
and stored in the engine model.
Args:
engine (EngineModel): The engine model
xb (float): The value of xb to reach [0,1]
Returns:
float: CA(xb)
"""
checkType(engine, EngineModel, "engine")
checkType(xb,float,"xb")
if not (xb > 0.0) and (xb <= 1.0):
raise ValueError("xb must be in range [0,1]")
return interp1d(engine.data["xb"], engine.data["CA"])(xb)
#############################################################################
#Define function for simplify loading:
[docs]
def loadModel(controlDict:Dictionary, *, fatal:bool=True) -> EngineModel|None:
"""
Convenient function for loading the engineModel from a control dictionary.
Args:
controlDict (Dictionary): The control dictionary to load the model from.
fatal (bool): If True, the function will raise an exception if the model cannot be loaded. Default is True.
Returns:
EngineModel: The engine model.
"""
try:
#Lookup engine model type and its dictionary
engineModelType:str = controlDict.lookup("engineModelType")
engineModelDict:Dictionary = controlDict.lookup(engineModelType + "Dict")
#Construct from run-time selector
model:EngineModel = EngineModel.selector(engineModelType, engineModelDict)
return model
except BaseException as err:
if fatal:
raise
#If not fatal, print the error
print(f"Failed loading model")
print(traceback.format_exc())