Source code for RCAIDE.Library.Methods.Aerodynamics.Common.Drag.total_drag
# RCAIDE/Library/Methods/Aerodynamics/Common/Drag/total_drag.py
#
# Created: Jun 2024, M. Clarke
# ----------------------------------------------------------------------------------------------------------------------
# Total Drag
# ----------------------------------------------------------------------------------------------------------------------
[docs]
def total_drag(state,settings,geometry):
"""
Computes the total drag coefficient by summing all individual drag components.
Parameters
----------
state : Data
Flight conditions and aerodynamic state containing:
- conditions.aerodynamics.coefficients.drag : Data
Drag coefficients containing:
- parasite.total : float
Total parasite drag coefficient [unitless]
- induced.total : float
Total induced drag coefficient [unitless]
- compressible.total : float
Compressibility drag coefficient [unitless]
- miscellaneous.total : float
Miscellaneous drag coefficient [unitless]
- cooling.total : float
Cooling drag coefficient [unitless]
- trim.total : float
Trim drag coefficient [unitless]
- form.total : float
Form drag coefficient [unitless]
settings : dict
Aerodynamic analysis settings containing:
- trim_drag_correction_factor : float
Correction factor for trim drag [unitless]
- drag_coefficient_increment : float
Additional drag coefficient increment [unitless]
geometry : Data
Aircraft geometry data structure
Returns
-------
None
Results are stored in state.conditions.aerodynamics.coefficients.drag.total
Notes
-----
This function aggregates all drag components into a total drag coefficient for the aircraft.
The calculation includes parasite, induced, compressibility, miscellaneous, cooling, trim,
form drag components, with optional correction factors and increments.
**Major Assumptions**
* All drag components are additive with no overlap
* Trim drag correction factor accounts for trim effects
* Drag coefficient increment allows for additional corrections
* All drag coefficients are normalized to the same reference area
**Theory**
The total drag coefficient is calculated as the sum of all drag components with corrections:
:math:`C_{D,total} = f_{trim} \\cdot (C_{D,parasite} + C_{D,induced} + C_{D,compressible} + C_{D,miscellaneous} + C_{D,cooling} + C_{D,trim} + C_{D,form} + \\Delta C_D)`
where:
- :math:`f_{trim}` is the trim drag correction factor
- :math:`C_{D,parasite}` is the parasite drag coefficient
- :math:`C_{D,induced}` is the induced drag coefficient
- :math:`C_{D,compressible}` is the compressibility drag coefficient
- :math:`C_{D,miscellaneous}` is the miscellaneous drag coefficient
- :math:`C_{D,cooling}` is the cooling drag coefficient
- :math:`C_{D,trim}` is the trim drag coefficient
- :math:`C_{D,form}` is the form drag coefficient
- :math:`\\Delta C_D` is the drag coefficient increment
See Also
--------
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.parasite_total
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.induced_drag
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.compressibility_drag
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.miscellaneous_drag
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.cooling_drag
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.trim_drag
RCAIDE.Library.Methods.Aerodynamics.Common.Drag.form_drag
"""
# unpack inputs
drag = state.conditions.aerodynamics.coefficients.drag
# various drag components
parasite_total = drag.parasite.total
induced_total = drag.induced.total
compressibility_total = drag.compressible.total
miscellaneous_drag = drag.miscellaneous.total
cooling_drag = drag.cooling.total
trim_drag = drag.trim.total
form_drag = drag.form.total
# total drag
drag.total = settings.trim_drag_correction_factor * (parasite_total + induced_total + compressibility_total + miscellaneous_drag \
+ cooling_drag + trim_drag + form_drag + settings.drag_coefficient_increment)
return
