jaxfluids.forcing package

Submodules

jaxfluids.forcing.forcing module

class jaxfluids.forcing.forcing.Forcing(domain_information: DomainInformation, material_manager: MaterialManager, unit_handler: UnitHandler, levelset_handler: LevelsetHandler | None, levelset_type: str, is_mass_flow_forcing: bool, is_temperature_forcing: bool, is_turb_hit_forcing: bool, mass_flow_target: float | function, flow_direction: str, temperature_target: float | function)[source]

Bases: object

Class that manages the computation of external forcing terms.

Currently implemented are: 1) Mass flow rate forcing 2) Temperature forcing 3) Homogeneous isotropic turbulence forcing

calculate_velocity_forcing_vector(vels: Array, vels_dash: Array, eta_s: int, timestep: float) → Array[source]

Calculates the velocity forcing vector for HIT forcing.

Parameters:

  • vels (jnp.ndarray) – Buffer of velocities.

  • vels_dash (jnp.ndarray) – Buffer of intermediate velocities which are obtained by integrating primes without forcing term.

  • eta_s (int) – Cut-off wavenumber up to which forcing is applied.

  • timestep (float) – Current time step.

Returns:

Buffer of the velocity forcing vector.

Return type:

jnp.ndarray

compute_forcings(primes: Array, cons: Array, levelset: Array | None, volume_fraction: Array | None, current_time: float, timestep_size: float, PID_e_new: float, PID_e_int: float, logger: Logger, primes_dash: Array | None = None, **kwargs) → Dict[source]

Computes forcings for temperature, mass flow and turbulence kinetic energy.

Parameters:

  • primes (jnp.ndarray) – buffer of primitive variables

  • primes_dash (Union[jnp.ndarray, None]) – buffer of primitive variables for next time step without forcing

  • cons (jnp.ndarray) – buffer of conservative variables

  • volume_fraction (Union[jnp.ndarray, None]) – buffer of volume fractions

  • mask_real (Union[jnp.ndarray, None]) – mask indicating the real fluid

  • current_time (float) – current physical simulation time

  • timestep_size (float) – current physical time step size

  • PID_e_new (float) – Error of previous timestep for PID controller

  • PID_e_int (float) – Accumalated error for PID controller

  • logger (Logger) – Logger for terminal output

Returns:

Dictionary containing buffers of forcings

Return type:

Dict

compute_mass_flow_forcing(cons: Array, primes: Array, volume_fraction: Array | None, current_time: float, timestep_size: float, PID_e_new: float, PID_e_int: float) → Tuple[Array, float, float, float, float][source]

Computes mass flow forcing

Parameters:

  • cons (jnp.ndarray) – Buffer of the conservative variables.

  • primes (jnp.ndarray) – Buffer of the primitive variables.

  • volume_fraction (Union[jnp.ndarray, None]) – Buffer of the volume fraction in two-phase flows.

  • current_time (float) – Current simulation time.

  • timestep_size (float) – Current time step.

  • PID_e_new (float) – Current PID error

  • PID_e_int (float) – Current PID integral error

Returns:

Buffer of the body force, current mass flow, mass flow target, PID error, PID integral error

Return type:

Tuple[jnp.ndarray, float, float]

compute_temperature_forcing(primes: Array, levelset: Array | None, volume_fraction: Array | None, current_time: float, timestep_size: float) → Tuple[Array, float][source]

Computes temperature forcing.

Parameters:

  • primes (jnp.ndarray) – Buffer of primitive variables.

  • levelset (Union[jnp.ndarray, None]) – Buffer of level-set field.

  • volume_fraction (Union[jnp.ndarray, None]) – Buffer of volume fraction field.

  • current_time (float) – Current simulation time.

  • timestep_size (float) – Current integration time step.

Returns:

Buffer of the forcing vector and the mean absolute error wrt the temperature target.

Return type:

Tuple[jnp.ndarray, float]

compute_turb_hit_forcing(primes: Array, primes_dash: Array, timestep: float) → Array[source]

Computes forcing for HIT

Parameters:

  • primes (jnp.ndarray) – Buffer of primitive variables.

  • primes_dash (jnp.ndarray) – Buffer of intermediate primitive variables which are obtained by integrating primes without forcing term.

  • timestep (float) – Current time step.

Returns:

Buffer of the forcing vector.

Return type:

jnp.ndarray

jaxfluids.forcing.pid_control module

class jaxfluids.forcing.pid_control.PIDControl(K_static: float = 1.0, K_P: float = 1.0, K_I: float = 1.0, K_D: float = 0.0, T_N: float = 0.5, T_V: float = 0.5)[source]

Bases: object

Standard PID controller. Used for example in the computation of the mass flow forcing in channel flows.

u = K_s * (K_p * e + K_i * e_int + K_d de/dt)

compute_output(current_value: float, target_value: float, dt: float, e_old: float, e_int: float) → Tuple[float, float, float][source]

Computes the control variable based on a standard PID controller.

Parameters:

  • current_value (float) – Current value of the control variable.

  • target_value (float) – Target value for the control variable.

  • dt (float) – Time step size.

  • e_old (float) – Previous instantaneous error of the control variable.

  • e_int (float) – Previous integral error of the control variable.

Returns:

Updated control variable, updated instantaneous and integral errors

Return type:

Tuple[float, float, float]

Module contents