CL_max_estimation.py

@File : CLmax_jet_transport.py @Date : 2023/03/24 @Author : Eytan Adler @Description : Max lift coefficient estimate for jet transport aircraft

class openconcept.aerodynamics.CL_max_estimation.CleanCLmax(**kwargs)

Bases: ExplicitComponent

Predict the maximum lift coefficient of the clean configuration. Method from Raymer (Equation 12.15, 1992 edition).

Inputs:

  • ac|aero|airfoil_Cl_max (float) – Maximum 2D lift coefficient of the wing airfoil (scalar, dimensionless)

  • ac|geom|wing|c4sweep (float) – Wing quarter chord sweep angle (scalar, radians)

Outputs:

CL_max_clean (float) – Maximum lift coefficient with no flaps or slats (scalar, dimensionless)

Options:

fudge_factor (float) – Optional multiplier on resulting lift coefficient, by default 1.0

class openconcept.aerodynamics.CL_max_estimation.FlapCLmax(**kwargs)

Bases: ExplicitComponent

Predict the maximum lift coefficient with Fowler flaps and slats extended. Method from Roskam Part VI Chapter 8 1989.

Inputs:

  • flap_extension (float) – Flap extension amount (scalar, deg)

  • ac|geom|wing|c4sweep (float) – Wing sweep at 25% mean aerodynamic chord (scalar, radians)

  • ac|geom|wing|toverc (float) – Wing thickness-to-chord ratio (scalar, dimensionless)

  • CL_max_clean (float) – Maximum lift coefficient with no flaps or slats (scalar, dimensionless)

Outputs:

CL_max_flap (float) – Maximum lift coefficient with flaps and slats extended (scalar, dimensionless)

Options:

  • flap_chord_frac (float) – Flap chord divided by wing chord, by default 0.2

  • wing_area_flapped_frac (float) – Flapped wing area divided by total wing area. Flapped wing area integrates the chord over any portions of the span that contain flaps (not just the area of the flap itself). By default 0.9.

  • slat_chord_frac (float) – Slat chord divided by wing chord, by default 0.1. Set to 0.0 to remove slats.

  • slat_span_frac (float) – Fraction of the wing span that has slats, by default 0.8

  • fudge_factor (float) – Optional multiplier on resulting lift coefficient, by default 1.0