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SUAVE
2.5.2
An Aerospace Vehicle Environment for Designing Future Aircraft
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SUAVE
2.5.2
An Aerospace Vehicle Environment for Designing Future Aircraft
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| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.aero_coeff.aero_coeff | ( | x, | |
| y, | |||
| cp, | |||
| al, | |||
| npanel | |||
| ) |
Compute airfoil force and moment coefficients about
the quarter chord point
Assumptions:
None
Source:
None
Inputs:
x - Vector of x coordinates of the surface nodes
y - Vector of y coordinates of the surface nodes
cp - Vector of coefficients of pressure at the nodes
al - Angle of attack in radians
npanel - Number of panels on the airfoil
Outputs:
cl - Airfoil lift coefficient
cd - Airfoil drag coefficient
cm - Airfoil moment coefficient about the c/4
Properties Used:
N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.airfoil_analysis.airfoil_analysis | ( | airfoil_geometry, | |
| alpha, | |||
| Re_L, | |||
npanel = 100, |
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batch_analysis = True, |
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airfoil_stations = [0], |
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initial_momentum_thickness = 1E-5, |
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tolerance = 1E0 |
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| ) |
This computes the aerodynamic polars as well as the boundary layer properties of
an airfoil at a defined set of reynolds numbers and angle of attacks
Assumptions:
Michel Criteria used for transition
Source:
N/A
Inputs:
airfoil_geometry - airfoil geometry points [unitless]
alpha - angle of attacks [radians]
Re_L - Reynolds numbers [unitless]
npanel - number of airfoil panels [unitless]
batch_analysis - boolean : If True: the specified number of angle of attacks and Reynolds [boolean]
numbers are used to create a table of 2-D results for each combination
Note: Can only accomodate one airfoil
If False:The airfoils specified are run and corresponding angle of attacks
and Reynolds numbers
Note: The number of airfoils, angle of attacks and reynolds numbers must
all the same dimension
Outputs:
airfoil_properties.
AoA - angle of attack [radians
Re - Reynolds number [unitless]
Cl - lift coefficients [unitless]
Cd - drag coefficients [unitless]
Cm - moment coefficients [unitless]
normals - surface normals of airfoil [unitless]
x - x coordinate points on airfoil [unitless]
y - y coordinate points on airfoil [unitless]
x_bl - x coordinate points on airfoil adjusted to include boundary layer [unitless]
y_bl - y coordinate points on airfoil adjusted to include boundary layer [unitless]
Cp - pressure coefficient distribution [unitless]
Ue_Vinf - ratio of boundary layer edge velocity to freestream [unitless]
dVe - derivative of boundary layer velocity [m/s-m]
theta - momentum thickness [m]
delta_star - displacement thickness [m]
delta - boundary layer thickness [m]
H - shape factor [unitless]
Cf - local skin friction coefficient [unitless]
Re_theta_t - Reynolds Number as a function of theta transition location [unitless]
tr_crit - critical transition criteria [unitless]
Properties Used:
N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.heads_method.heads_method | ( | npanel, | |
| nalpha, | |||
| nRe, | |||
| DEL_0, | |||
| THETA_0, | |||
| DELTA_STAR_0, | |||
| TURBULENT_SURF, | |||
| RE_L, | |||
| TURBULENT_COORD, | |||
| VE_I, | |||
| DVE_I, | |||
| batch_analysis, | |||
| tol | |||
| ) |
Computes the boundary layer characteristics in turbulent flow pressure gradients Source: Head, M. R., and P. Bandyopadhyay. "New aspects of turbulent boundary-layer structure." Journal of fluid mechanics 107 (1981): 297-338. Assumptions: None Inputs: nalpha - number of angle of attacks [unitless] nRe - number of reynolds numbers [unitless] batch_analysis - flag for batch analysis [boolean] DEL_0 - intital bounday layer thickness [m] DELTA_STAR_0 - initial displacement thickness [m] THETA_0 - initial momentum thickness [m] TURBULENT_SURF - normalized length of surface [unitless] RE_L - Reynolds number [unitless] TURBULENT_COORD- x coordinate on surface of airfoil [unitless] VE_I - boundary layer velocity at transition location [m/s-m] DVE_I - intial derivative value of boundary layer velocity at transition location [unitless] npanel - number of points on surface [unitless] tol - boundary layer error correction tolerance [unitless] Outputs: RESULTS. X_H - reshaped distance along airfoil surface [unitless] THETA_H - momentum thickness [m] DELTA_STAR_H - displacement thickness [m] H_H - shape factor [unitless] CF_H - friction coefficient [unitless] RE_THETA_H - Reynolds number as a function of momentum thickness [unitless] RE_X_H - Reynolds number as a function of distance [unitless] DELTA_H - boundary layer thickness [m] Properties Used: N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.hess_smith.hess_smith | ( | x_coord, | |
| y_coord, | |||
| alpha, | |||
| Re, | |||
| npanel, | |||
| batch_analyis | |||
| ) |
Computes the incompressible, inviscid flow over an airfoil of arbitrary shape using the Hess-Smith panel method.
Assumptions:
None
Source: "An introduction to theoretical and computational
aerodynamics", J. Moran, Wiley, 1984
Inputs
x - Vector of x coordinates of the surface [unitess]
y - Vector of y coordinates of the surface [unitess]
batch_analyis - flag for batch analysis [boolean]
alpha - Airfoil angle of attack [radians]
npanel - Number of panels on the airfoil. The number of nodes [unitess]
is equal to npanel+1, and the ith panel goes from node
i to node i+1
Outputs
cl - Airfoil lift coefficient [unitless]
cd - Airfoil drag coefficient [unitless]
cm - Airfoil moment coefficient about the c/4 [unitless]
x_bar - Vector of x coordinates of the surface nodes [unitless]
y_bar - Vector of y coordinates of the surface nodes [unitless]
cp - Vector of coefficients of pressure at the nodes [unitless]
Properties Used:
N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.infl_coeff.infl_coeff | ( | x, | |
| y, | |||
| xbar, | |||
| ybar, | |||
| st, | |||
| ct, | |||
| npanel, | |||
| nalpha, | |||
| nRe, | |||
| batch_analyis | |||
| ) |
Compute the matrix of aerodynamic influence coefficients for later use
Assumptions:
None
Source:
None
Inputs
x - Vector of x coordinates of the surface nodes [unitless]
y - Vector of y coordinates of the surface nodes [unitless]
xbar - x-coordinate of the midpoint of each panel [unitless]
ybar - y-coordinate of the midpoint of each panel [unitless]
st - np.sin(theta) for each panel [radians]
ct - np.cos(theta) for each panel [radians]
npanel - Number of panels on the airfoil [unitless]
Outputs
ainfl - Aero influence coefficient matrix [unitless]
Properties Used:
N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.panel_geometry.panel_geometry | ( | x, | |
| y, | |||
| npanel, | |||
| nalpha, | |||
| nRe | |||
| ) |
Computes airfoil surface panelization parameters for later use in
the computation of the matrix of influence coefficients.
Assumptions:
None
Source:
None
Inputs:
x - Vector of x coordinates of the surface nodes [unitless]
y - Vector of y coordinates of the surface nodes [unitless]
npanel - Number of panels on the airfoil [unitless]
Outputs:
l - Panel lengths [unitless]
st - np.sin(theta) for each panel [radians]
ct - np.cos(theta) for each panel [radians]
xbar - x-coordinate of the midpoint of each panel [unitless]
ybar - y-coordinate of the midpoint of each panel [unitless]
Properties Used:
N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.thwaites_method.thwaites_method | ( | npanel, | |
| nalpha, | |||
| nRe, | |||
| L, | |||
| RE_L, | |||
| X_I, | |||
| VE_I, | |||
| DVE_I, | |||
| batch_analysis, | |||
| tol, | |||
| THETA_0 | |||
| ) |
Computes the boundary layer characteristics in laminar flow pressure gradients Source: Thwaites, Bryan. "Approximate calculation of the laminar boundary layer." Aeronautical Quarterly 1.3 (1949): 245-280. Assumptions: None Inputs: npanel - number of points on surface [unitless] nalpha - number of angle of attacks [unitless] nRe - number of reynolds numbers [unitless] batch_analysis - flag for batch analysis [boolean] THETA_0 - initial momentum thickness [m] L - normalized length of surface [unitless] RE_L - Reynolds number [unitless] X_I - x coordinate on surface of airfoil [unitless] VE_I - boundary layer velocity at transition location [m/s] DVE_I - initial derivative value of boundary layer velocity at transition location [m/s-m] tol - boundary layer error correction tolerance [unitless] Outputs: RESULTS. X_T - reshaped distance along airfoil surface [unitless] THETA_T - momentum thickness [m] DELTA_STAR_T - displacement thickness [m] H_T - shape factor [unitless] CF_T - friction coefficient [unitless] RE_THETA_T - Reynolds number as a function of momentum thickness [unitless] RE_X_T - Reynolds number as a function of distance [unitless] DELTA_T - boundary layer thickness [m] Properties Used: N/A
| def SUAVE.Methods.Aerodynamics.Airfoil_Panel_Method.velocity_distribution.velocity_distribution | ( | qg, | |
| x, | |||
| y, | |||
| xbar, | |||
| ybar, | |||
| st, | |||
| ct, | |||
| alpha, | |||
| Re, | |||
| npanel | |||
| ) |
Compute the tangential velocity distribution at the
midpoint of each panel
Source:
None
Assumptions:
None
Inputs:
qg - Vector of source/sink and vortex strengths [unitless]
x - Vector of x coordinates of the surface nodes [unitless]
y - Vector of y coordinates of the surface nodes [unitless]
xbar - x-coordinate of the midpoint of each panel [unitless]
ybar - y-coordinate of the midpoint of each panel [unitless]
st - np.sin(theta) for each panel [radians]
ct - np.cos(theta) for each panel [radians]
al - Angle of attack in radians [radians]
npanel - Number of panels on the airfoil [unitless]
Outputs:
vt_2d - Vector of tangential velocities
Properties Used:
N/A
1.8.15