calculate_willans_factors

calculate_willans_factors(co2_params_calibrated, engine_fuel_lower_heating_value, engine_stroke, engine_capacity, min_engine_on_speed, fmep_model, engine_speeds_out, engine_powers_out, times, velocities, accelerations, motive_powers, engine_coolant_temperatures, missing_powers, angle_slopes)

Calculates the Willans factors.

Parameters:

• co2_params_calibrated (lmfit.Parameters) –

  CO2 emission model parameters (a2, b2, a, b, c, l, l2, t, trg).

  The missing parameters are set equal to zero.

• engine_fuel_lower_heating_value (float) – Fuel lower heating value [kJ/kg].
• engine_stroke (float) – Engine stroke [mm].
• engine_capacity (float) – Engine capacity [cm3].
• min_engine_on_speed (float) – Minimum engine speed to consider the engine to be on [RPM].
• fmep_model (FMEP) – Engine FMEP model.
• engine_speeds_out (numpy.array) – Engine speed vector [RPM].
• engine_powers_out (numpy.array) – Engine power vector [kW].
• times (numpy.array) – Time vector [s].
• velocities (numpy.array) – Velocity vector [km/h].
• accelerations (numpy.array) – Acceleration vector [m/s2].
• motive_powers (numpy.array) – Motive power [kW].
• engine_coolant_temperatures (numpy.array) – Engine coolant temperature vector [°C].
• missing_powers (numpy.array) – Missing engine power [kW].
• angle_slopes (numpy.array) – Angle slope vector [rad].

Returns:

Willans factors:

• av_velocities [km/h]
• av_slope [rad]
• distance [km]
• init_temp [°C]
• av_temp [°C]
• end_temp [°C]
• av_vel_pos_mov_pow [kw/h]
• av_pos_motive_powers [kW]
• sec_pos_mov_pow [s]
• av_neg_motive_powers [kW]
• sec_neg_mov_pow [s]
• av_pos_accelerations [m/s2]
• av_engine_speeds_out_pos_pow [RPM]
• av_pos_engine_powers_out [kW]
• engine_bmep_pos_pow [bar]
• mean_piston_speed_pos_pow [m/s]
• fuel_mep_pos_pow [bar]
• fuel_consumption_pos_pow [g/sec]
• willans_a [g/kWh]
• willans_b [g/h]
• specific_fuel_consumption [g/kWh]
• indicated_efficiency [-]
• willans_efficiency [-]

Return type:

dict