PySAGAS CFD Module

• Oblique / Prandtl-Meyer Flow Solver
  • OPM
• Cart3D CFD Interface
• PySAGAS CFD Utilities
  • AbstractDeck
  • AeroDeck
  • Deck
  • MultiDeck
  • SensDeck

class pysagas.cfd.solver.AbstractFlowSolver

Abstract interface for flow solvers.

abstract __init__(**kwargs)

Return type:

None

class pysagas.cfd.solver.FlowResults

A class containing the aerodynamic force and moment information with respect to design parameters.

freestream

The freestream flow state.

Type:

FlowState

net_force

The net force in cartesian coordinate frame (x,y,z).

Type:

pd.DataFrame

m_sense

The net moment in cartesian coordinate frame (x,y,z).

Type:

pd.DataFrame

__init__(freestream, net_force, net_moment)

Parameters:

• freestream (FlowState) –

• net_force (Vector) –

• net_moment (Vector) –

Return type:

None

coefficients(A_ref=1.0, c_ref=1.0)

Calculate the aerodynamic coefficients CL, CD and Cm.

Parameters:

• A_ref (float, optional) – The reference area (m^2). The default is 1 m^2.

• c_ref (float, optional) – The reference length (m). The default is 1 m.

Return type:

C_L, C_D, C_m

class pysagas.cfd.solver.FlowSolver

Base class for CFD flow solver.

__init__(cells, freestream=None, verbosity=1)

Instantiates the flow solver.

Parameters:

• cells (list[Cell]) – A list of the cells describing the geometry.

• freestream (Flowstate, optional) – The free-stream flow state. The default is the freestream provided upon instantiation of the solver.

• verbosity (int, optional) – The verbosity of the solver. The default is 1.

Return type:

None

static body_to_wind(v, aoa)

Converts a vector from body axes to wind axes.

Parameters:

• v (Vector) – The result to transform.

• aoa (float) – The angle of attack, specified in degrees.

Returns:

r – The transformed result.

Return type:

Vector

save(name, attributes)

Save the solution to VTK file format. Note that the geometry mesh must have been loaded from a parser which includes connectivity information (eg. PyMesh or TRI).

Parameters:

• name (str) – The filename prefix of the desired output file.

• attributes (Dict[str, list]) – The attributes dictionary used to initialise the file writer. Note that this is not required when calling solve from a child FlowSolver.

solve(freestream=None, mach=None, aoa=None)

Run the flow solver.

Parameters:

• freestream (Flowstate, optional) – The free-stream flow state. The default is the freestream provided upon instantiation of the solver.

• mach (float, optional) – The free-stream Mach number. The default is that specified in the freestream flow state.

• aoa (float, optional) – The free-stream angle of attack. The default is that specified in the freestream flow state.

Returns:

result – The flow results.

Return type:

FlowResults

:raises Exception : when no freestream can be found.:

solve_sens(freestream=None, mach=None, aoa=None)

Run the flow solver to obtain sensitivity information.

Parameters:

• freestream (Flowstate, optional) – The free-stream flow state. The default is the freestream provided upon instantiation of the solver.

• Mach (float, optional) – The free-stream Mach number. The default is that specified in the freestream flow state.

• aoa (float, optional) – The free-stream angle of attack. The default is that specified in the freestream flow state.

• mach (float | None) –

Return type:

SensitivityResults

:raises Exception : when no freestream can be found.:

sweep(aoa_range, mach_range)

Evaluate the aerodynamic coefficients over a sweep of angle of attack and mach numbers.

Parameters:

• aoa_range (list[float]) – The angles of attack to evaluate at, specified in degrees.

• mach_range (list[float]) – The Mach numbers to evaluate at.

Returns:

results – A Pandas DataFrame of the aerodynamic coefficients at each angle of attack and Mach number combination.

Return type:

pd.DataFrame

class pysagas.cfd.solver.SensitivityResults

A class containing the aerodynamic force and moment sensitivity information with respect to design parameters.

freestream

The freestream flow state.

Type:

FlowState

f_sense

The force sensitivities in cartesian coordinate frame (x,y,z).

Type:

pd.DataFrame

m_sense

The moment sensitivities in cartesian coordinate frame (x,y,z).

Type:

pd.DataFrame

__init__(f_sens, m_sens, freestream=None)

Parameters:

• f_sens (DataFrame) –

• m_sens (DataFrame) –

• freestream (FlowState | None) –

Return type:

None

coefficients(A_ref=1.0, c_ref=1.0)

Calculate the aerodynamic coefficients CL, CD and Cm.

Parameters:

• A_ref (float, optional) – The reference area (m^2). The default is 1 m^2.

• c_ref (float, optional) – The reference length (m). The default is 1 m.

Return type:

A tuple (cf_sens, cm_sens) containing the force and moment coefficient sensitivities.