StepUvlm

class sharpy.solvers.stepuvlm.StepUvlm

StepUVLM is the main solver to use for unsteady aerodynamics.

The desired flow field is injected into the simulation by means of a generator. For a list of available velocity field generators see the documentation page on generators which can be found under SHARPy Source Code.

Typical generators could be:

• SteadyVelocityField

• GustVelocityField

• TurbVelocityField

amongst others.

The settings that this solver accepts are given by a dictionary, with the following key-value pairs:

Name	Type	Description	Default	Options
print_info	bool	Print info to screen	True
num_cores	int	Number of cores to use in the VLM lib	0
n_time_steps	int	Number of time steps to be run	100
convection_scheme	int	0: fixed wake, 2: convected with background flow;``3``: full force-free wake	3	0, 2, 3
dt	float	Time step	0.1
iterative_solver	bool	Not in use	False
iterative_tol	float	Not in use	0.0001
iterative_precond	bool	Not in use	False
velocity_field_generator	str	Name of the velocity field generator to be used in the simulation	SteadyVelocityField
velocity_field_input	dict	Dictionary of settings for the velocity field generator	{}
gamma_dot_filtering	int	Filtering parameter for the Welch filter for the Gamma_dot estimation. Used when unsteady_force_contribution is on.	0
rho	float	Air density	1.225
cfl1	bool	If it is True, it assumes that the discretisation complies with CFL=1	True
vortex_radius	float	Distance between points below which induction is not computed	sharpy.utils.constants.vortex_radius_def
vortex_radius_wake_ind	float	Distance between points below which induction is not computed in the wake convection	sharpy.utils.constants.vortex_radius_def
interp_coords	int	Coordinates to use for wake description: cartesian(0) or cylindrical_z(1)	0	0, 1
filter_method	int	Method to filter the points: no filter (0) moving average(2)	0	0, 2
interp_method	int	Method of interpolation: linear(0), parabolic(1), splines(2), slerp around z(3), slerp around yaw_slerp(4)	0	0, 1, 2, 3, 4
yaw_slerp	float	Yaw angle in radians to be used when interp_metod == 4	0
centre_rot	list(float)	Coordinates of the centre of rotation to perform slerp interpolation or cylindrical coordinates	[0.0, 0.0, 0.0]
quasi_steady	bool	Use quasi-steady approximation in UVLM	False
only_nonlifting	bool	Consider nonlifting body interactions	False
nonlifting_body_interactions	bool	Consider nonlifting body interactions	False
phantom_wing_test	bool	Debug option	False
centre_rot_g	list(float)	Centre of rotation in G FoR around which rbm_vel_g is applied	[0.0, 0.0, 0.0]
ignore_first_x_nodes_in_force_calculation	int	Ignores the forces on the first user-specified number of nodes of all surfaces.	0

initialise(data, custom_settings=None, restart=False)

To be called just once per simulation.

run(**kwargs)

Runs a step of the aerodynamics as implemented in UVLM.