5. API Reference

5.1. Installing Flow360 Client

The Flow360 client can be installed (and updated) from PyPI. Make sure you have the Python setuptools. If not, sudo apt-get install python3-setuptools.

pip3 install flow360client
pip3 install --upgrade flow360client

5.2. Sign in with you Account and Password

An account can be created at https://client.flexcompute.com/app/signup.

python3
>>> import flow360client
enter your email registered at flexcompute:********@gmail.com
Password: ***********
Do you want to keep logged in on this machine ([Y]es / [N]o)Y

Once you have installed the Flow360 client and signed into it, you can run your first case using the ONERA M6 Wing tutorial in the Quick Start section of this document.

5.3. Configuration Parameters

The current Mesh processor and Solver input configuration parameters for Flow360 are:

5.3.1. Flow360Mesh.json

Type

Options

Default

Description

boundaries

noSlipWalls

[]

list of names of boundary patches, e.g. [2,3,7] (for .ugrid), [“blk-1/wall1”,”blk-2/wall2”] (for .cgns)

slidingInterfaces

[]

list of pairs of sliding interfaces

stationaryPatches

[]

list of names of stationary boundary patches, e.g. [“stationaryField/interface”]

rotatingPatches

[]

list of names of dynamic boundary patches, e.g. [“rotatingField/interface”]

axisOfRotation

[]

axis of rotation, e.g. [0,0,-1]

centerOfRotation

[]

center of rotation, e.g. [0,0,0]

5.3.2. Flow360.json

5.3.2.1. geometry

Options

Default

Description

refArea

1

The reference area of the geometry

momentCenter

[0.0, 0.0, 0.0]

The x, y, z moment center of the geometry in grid units

momentLength

[1.0, 1.0, 1.0]

The x, y, z moment reference lengths

5.3.2.2. runControl

Options

Default

Description

restart

FALSE

the solutions are initialized from restarting files or not (no need to set by users)

startAlphaControlPseudoStep

-1

pseudo step at which to start targetCL control. -1 is no trim control. (steady only)

targetCL

-1

The desired trim CL to achieve (assocated with startAlphaControlPseudoStep)

5.3.2.3. freestream

Options

Default

Description

Reynolds

Not required if muRef exists

Nondimensional Reynolds number. Reynolds number should be computed based on the reference length in grid units. For example, if you have a mesh with a MAC of 100 in grid units and want to simulate a physical Reynolds number of 1M, then you should set Reynolds = 100,000.

muRef

Not required if Reynolds exists

refererence mu(non-dimenstional) in our solver

Mach

REQUIRED

The Mach number, the ratio of freestream speed to the speed of sound.

MachRef

Required if Mach == 0

The reference Mach number to compute the mu, CL/CD, coefficients, etc…

Temperature

REQUIRED

The reference temperature in Kelvin.

alphaAngle

REQUIRED

The angle of attack in degrees

betaAngle

REQUIRED

The side slip angle in degrees

5.3.2.4. boundaries

Type

Format

Description

SlipWall

"boundary_name" :
{
 "type" : "SlipWall"
}

Slip wall condition. Also used for symmetry.

NoSlipWall

"boundary_name" :
{
 "type" : "NoSlipWall",
 "Velocity": [
  float or "expression" (default: 0),
  float or "expression" (default: 0),
  float or "expression" (default: 0)]
}

Sets no-slip wall condition. Optionally, a tangential velocity can be prescribed on the wall using the keyword “Velocity”.

IsothermalWall

"boundary_name" :
{
 "type" : "IsothermalWall",
 "Temperature":
  float or "expression" (REQUIRED),
 "Velocity": [
  float or "expression" (default: 0),
  float or "expression" (default: 0),
  float or "expression" (default: 0)]
}

Isothermal wall boundary condition. “Temperature” is specified in Kelvin. Optionally a tangential velocity can be presribed on the wall using the keyword “Velocity”.

Freestream

"boundary_name" :
{
 "type" : "Freestream",
 "Velocity": [
  float or "expression" (default: freestream),
  float or "expression" (default: freestream),
  float or "expression" (default: freestream)]
}

External freestream condition. Optionally, an expression for each of the velocity components can be specified using the keyword “Velocity”.

SubsonicOutflowPressure

"boundary_name" :
{
 "type" : "SubsonicOutflowPressure",
 "staticPressureRatio" : float
}

Subsonic outflow, enforced through static pressure ratio.

SubsonicOutflowMach

"boundary_name" :
{
 "type" : "SubsonicOutflowMach",
 "MachNumber" : float
}

Static pressure outflow boundary condition set via a specified subsonic Mach number.

SubsonicInflow

"boundary_name" :
{
 "type" : "SubsonicInflow",
 "totalPressureRatio" : float,
 "totalTemperatureRatio" : float,
 "rampSteps" : Integer
}

Subsonic inflow (enforced via total pressure ratio and total temperature ratio) for nozzle or tunnel plenum.

MassOutflow

"boundary_name" :
{
 "type" : "MassOutflow",
 "massFlowRate" : float
}

Specification of massflow out of the control volume.

MassInflow

"boundary_name" :
{
 "type" : "MassInflow",
 "massFlowRate" : float
}

Specification of massflow into the control volume.

Note: “expression” is an expression with “x”, “y”, “z” as independent variables.

5.3.2.5. volumeOutput

Options

Default

Description

outputFormat

paraview

“paraview” or “tecplot”

animationFrequency

-1

Frequency at which volume output is saved. -1 is at end of simulation

startAverageIntegrationStep

0

Sub-iteration or time-step to start averaging forces/moments

computeTimeAverages

FALSE

Whether or not to compute time-averaged quantities

primitiveVars

TRUE

Outputs rho, u, v, w, p

vorticity

FALSE

Vorticity

residualNavierStokes

FALSE

5 components of the N-S residual

residualTurbulence

FALSE

nuHat

T

FALSE

Temperature

s

FALSE

Entropy

Cp

TRUE

Coefficient of pressure. \(C_p=(\frac{p-p_{inf}}{\frac{1}{2}\rho_{inf}{U_{ref}}^2})\). The \(p_{inf}\) is the static pressure of freestream. The \(\rho_{inf}\) and \(U_{ref}\) the same as those in CfVec.

mut

TRUE

Turbulent viscosity

nuHat

TRUE

nuHat

kOmega

FALSE

k and omega when using kOmegaSST model

mutRatio

FALSE

mut/mu_inf

Mach

TRUE

Mach number

VelocityRelative

FALSE

velocity in rotating frame

qcriterion

FALSE

Q criterion

gradW

FALSE

Gradient of W

5.3.2.6. surfaceOutput

Options

Default

Description

outputFormat

paraview

“paraview” or “tecplot”

animationFrequency

-1

Frequency at which surface output is saved. -1 is at end of simulation

primitiveVars

FALSE

rho, u, v, w, p

Cp

FALSE

Coefficient of pressure

Cf

FALSE

Skin friction coefficient

heatFlux

FALSE

Heat Flux

CfVec

FALSE

Viscous stress coefficient vector. For example, \(C_{f_{Vec}}[3]=\frac{\tau_{wall}[3]}{\frac{1}{2}\rho_{inf}U_{ref}^2}\). The \(\tau_{wall}\) is the vector of viscous stress on the wall. \(\rho_{inf}\) is the density of freestream, \(U_{ref}\) is the \(C_{inf}*Mach_{ref}\), where the \(C_{inf}\) is the speed of sound of freestream, and the \(Mach_{ref}\) is the value specified at the “freestream” section of Flow360.json. If the \(Mach_{ref}\) is not specified in the Flow360.json, its default value is equal to the “Mach” in “freestream” section of Flow360.json.

yPlus

FALSE

y+

wallDistance

FALSE

Wall Distance

Mach

FALSE

Mach number

nodeForcesPerUnitArea

FALSE

\(nodeForcesPerUnitArea=\frac{\tau_{wall}[3]-(p-p_{inf})*normal[3]} {\rho_{inf}C_{inf}^2}\), where the \(normal[3]\) is the unit normal vector pointing from solid to fluid.

residualSA

FALSE

Spalart-Allmaras residual magnitude

5.3.2.7. sliceOutput

Options

Default

Description

outputFormat

paraview

“paraview” or “tecplot”

animationFrequency

-1

Frequency at which slice output is saved. -1 is at end of simulation

primitiveVars

TRUE

Outputs rho, u, v, w, p

vorticity

FALSE

Vorticity

residualNavierStokes

FALSE

Residual components for Navier-stokes equations

residualTurbulence

FALSE

Residual magnitude of turbulence equations

T

FALSE

Temperature

s

FALSE

Entropy

Cp

FALSE

Coefficient of pressure

mut

FALSE

Turbulent viscosity

mutRatio

FALSE

mut/mu_inf

Mach

TRUE

Mach number

gradW

FALSE

gradient of W

slices

[]

List of slices to save after the solver has finished

sliceName

string

sliceNormal

[x, y, z]

sliceOrigin

[x, y, z]

5.3.2.9. turbulenceModelSolver

Options

Default

Description

modelType

SpalartAllmaras

Turbulence model type can be: “SpalartAllmaras” or “kOmegaSST”

absoluteTolerance

1.00E-08

Tolerance for the SA residual, below which the solver goes to the next physical step

relativeTolerance

1.00E-02

Tolerance to the ratio of residual of current pseudoStep to the initial residual, below which the solver goes to the next physical step

linearIterations

20

Number of linear iterations for the SA linear system

updateJacobianFrequency

4

Frequency at which to update the Jacobian

equationEvalFrequency

4

Frequency at which to evaluate the turbulence equation in loosely-coupled simulations

kappaMUSCL

-1

Kappa for the muscle scheme, range from [-1, 1] with 1 being unstable.

rotationCorrection

FALSE

SARC model

orderOfAccuracy

2

Order of accuracy in space

maxForceJacUpdatePhysicalSteps

0

When which physical steps, the jacobian matrix is updated every pseudo step

DDES

FALSE

_true_ Enables DDES simulation

5.3.2.10. initialCondition

Options

Default

Description

type

“freestream”

Use the flow conditions defined in freestream section to set initial condition. Could be “freestream” or an “expression”

5.3.2.11. timeStepping

Options

Default

Description

maxPhysicalSteps

1

Maximum physical steps

timeStepSize

“inf”

Time step size in physical step marching, “inf” means steady solver

maxPseudoSteps

2000

Maximum pseudo steps within one physical step

CFL->initial

5

Initial CFL for solving pseudo time step

CFL->final

200

Final CFL for solving pseudo time step

CFL->rampSteps

40

Number of steps before reaching the final CFL within 1 physical step

5.3.2.12. slidingInterfaces (list)

Options

Default

Description

stationaryPatches

Empty

a list of static patch names of an interface

rotatingPatches

Empty

a list of dynamic patch names of an interface

thetaRadians

Empty

expression for rotation angle (in radians) as a function of time

thetaDegrees

Empty

expression for rotation angle (in degrees) as a function of time

omegaRadians

Empty

non-dimensional rotating speed, radians/nondim-unit-time

omegaDegrees

Empty

non-dimensional rotating speed, degrees/nondim-unit-time

centerOfRotation

Empty

a 3D array, representing the origin of rotation, e.g. [0,0,0]

axisOfRotation

Empty

a 3D array, representing the rotation axis, e.g. [0,0,1]

volumeName

Empty

a list of dynamic volume names related to the above {omega, centerOfRotation, axisOfRotation}

5.3.2.13. actuatorDisks (list)

Options

Default

Description

center

Empty

center of the actuator disk

axisThrust

Empty

direction of the thrust, it is an unit vector

thickness

Empty

thickness of the actuator disk

forcePerArea->radius (list)

Empty

radius of the sampled locations in grid unit

forcePerArea->thrust (list)

Empty

force per area along the axisThrust, positive means the axial force follows the same direction of “axisThrust”. It is non-dimensional.

forcePerArea->circumferential (list)

Empty

force per area in circumferential direction, positive means the circumferential force follows the same direction of “axisThrust” based on right hand rule. It is non-dimensional.