Input

• AFLR3 (.ugrid)
• CGNS (single and multi-block)

Output

• ParaView (.pvtu)
• Tecplot (.dat and .szplt)

User Interface

• Web Interface


• Python API

Flow360 currently specializes in the simulation of external and internal flows at a wide range of speed regime. Applications include, but are certainly not limited to aircraft, cars, and engine components.

Performance

Flow360 is extremely fast compared to current industry-leading solvers. For example, Flow360 can converge the 26M-node Common Research Model from the High Lift Workshop in just 90 seconds. For comparison, NASA’s FUN3D solver requires 2 hours to converge the same mesh using 360 cores on Amazon Web Service C5 instances.

Coefficient of friction (Cf) on the surface of the Common Research Model.

Flow360 has been validated against many large-scale test cases

High Lift Workshop Common Research Model

Flow360 has been validated against the committee-provided meshes in the 3rd AIAA High Lift Workshop. The following figures show the results obtained on the NAAS Common Research Model (CRM) with a full flap gap, meshed with mixed hexahedral, tetrahedral, prism, and pyramid elements.

Grid convergence of Flow360 compared to the participants of the 3rd AIAA CFD High Lift Prediction Workshop in 2017. The x-axis is the scale of the expected numerical error; the y-axis shows the lift (left plots) and drag (right plots) coefficients computed on various grids, at 8 (upper plots) and 16 (lower plots) degrees angle of attack.
Coefficient of pressure (Cp, left) and coefficient of skin friction (Cf, right) on an inboard cross section of the wing. Thick blue dots are Flow360 and other thin lines are the participants of the 3rd AIAA CFD High Lift Prediction Workshop. Coefficient of pressure (Cp, left) and coefficient of skin friction (Cf, right) on a middle cross section of the wing. Thick blue dots are Flow360 and other thin lines are the participants of the 3rd AIAA CFD High Lift Prediction Workshop. Coefficient of pressure (Cp, left) and coefficient of skin friction (Cf, right) on an outboard cross section of the wing. Thick blue dots are Flow360 and other thin lines are the participants of the 3rd AIAA CFD High Lift Prediction Workshop.

Drag Prediction Workshop

The 6th AIAA CFD Drag Prediction Workshop (DPW).

Please contact John Moore if you would like to see additional validation data.

How do I download or view a finished case result?

To download the surface data (surface distributions and slices):

Replace the second parameter with your target location and output file name, ending with '.tar.gz'.

To download the entire flowfield:

My case is still running, but how can I check current residual or surface force result?

Where are my AWS credentials stored locally?

Your AWS credential is encrypted and stored locally (if you hit Yes previously at authentication step) at

For security, your password is stored as hashed value, so nobody can guess your password.

How to check my mesh processing status?

How can I delete my mesh or case?

Caution: You won't be able to recover your deleted case or mesh files including its results after your deletion.

Python API Tutorial

This tutorial will show you how to set up and run the High Lift Workshop CRM case with the Flow360 Python API.

Step 1. Download python client and install

Make sure you have setuptools. If not, sudo apt-get install python3-setuptools

Step 2. Signing in with your account and password

An account can be created at www.flexcompute.com

Step 3. Download the HLCRM case

Download the HLCRM mesh and .mapbc file

Step 3. Upload a mesh file

First, specify a list of no-slip walls. If you have a .mapbc file, there is a function that will do this for you:

Then submit a mesh

Replace above fname and noSlipWalls with your own file path and parameter. Parameter inputs of mesh name and tags are optional. Upon this command finishing, it will return the mesh Id ''. Use that for next step.

Note: By default, submitted mesh file will be processed using latest major release (e.g. 0.2.x) . If you want to run with another version of the solve, please specify in the argument as example:

Step 4. Upload a case file

First, prepare a JSON input file, either manually or by using the fun3d_to_flow360.py script:

Then submit a case:

Replace the mesh id generated from above step, and give your own config path. Parameter inputs of caseName and tags are optional. Upon this command finishing, it will return the case Id ''. Use that for next step.

Step 5. Checking the case status

Look for field of "status" from printed result. A case status can be:
1) queued
2) running
3) completed

Current Solver Input Options and Default Values

You can download the latest Flow360.json configuration file here

Type	Options	Default	Description
geometry	refArea	1.0	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
freestream	Reynolds	REQUIRED	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 the you should set Reynolds = 100,000.
	Mach	REQUIRED	The Mach number, the ratio of freestream speed to the speed of sound.
	Temperature	REQUIRED	The reference temperature in Kelvin.
	alphaAngle	REQUIRED	The angle of attack in degrees
	betaAngle	REQUIRED	The side slip angle in degrees
runControl	firstOrderIterations	-1	Number of iterations to perform before turning on second order accuracy
	startControl	-1	Time step at which to start targetCL control. -1 is no trim control.
	targetCL	-1	The desired trim CL to achieve
	maxSteps	10000	the maximum number of time steps or iterations to take
boundaries	YOUR_FIRST_BOUNDARY_ID: type	YOUR_BOUNDARY_TYPE	List of boundary conditions.
	YOUR_SECOND_BOUNDARY_ID: type	YOUR_BOUNDARY_TYPE
volumeOutput	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
	mut	true	Turbulent viscosity
	nuHat	true	mut/mu_inf
	mutRatio	false	mut/mu_inf
	Mach	10000	Mach number
	gradW	false	Gradient of W
surfaceOutput	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
	CfVec	false	Viscous stress coefficient vector
	yPlus	false	y+
	wallDistance	false	Wall Distance
	Mach	false	Mach number
	residualSA	false	Spalart-Allmaras residual magnitude
sliceOutput	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
navierStokesSolver	tolerance	1e-10	Tolerance for the NS residual, below which the solver exits
	CFL: initial	10.0	Exponential CFL ramping, from initial to final, over _rampSteps_ steps
	CFL: final	200.0
	CFL: rampSteps	200
	linearIterations	25	Number of linear solver iterations
	kappaMUSCL	-1.0	Kappa for the MUSCL scheme, range from [-1, 1], with 1 being unstable.
	maxDt	1.0e100	Maximum time step
	startEnforcingMaxDtStep	-1	Time step at which to start enforcing maxDtStep. Default of -1 does not enforce a max time step.
	updateJacobianFrequency	4	Frequency at which the jacobian is updated.
	equationEvalFrequency	1	Frequency at which to update the NS equation in loosely-coupled simulations
	viscousWaveSpeedScale	0.0	Scales the wave speed acording to a viscous flux. 0.0 is no speed correction, with larger values providing a larger viscous wave speed correction.
turbulenceModelSolver	modelType	SpalartAllmaras	Only SA supported at this point
	CFL: initial	10.0	Exponential CFL ramping, from initial to final, over _rampSteps_ steps
	CFL: final	200.0
	CFL: rampSteps	200.0
	linearIterations	15	Number of linear iterations for the SA linear system
	updateJacobianFrequency	1	Frequency at which to update the Jacobian
	equationEvalFrequency	4	Frequency at which to evaluate the turbulence equation in loosely-coupled simulations
	kappaMUSCL	-1.0	Kappa for the muscle scheme, range from [-1, 1] with 1 being unstable.
	rotationCorrection	false	SARC model
	DDES	false	_true_ Enables DDES simulation

Flow360 Version history

Results between major versions (e.g. x.y.0) may differ slightly. However, results among minor versions (e.g. 0.2.x) will not change.

release-0.1

• Viscous gradient scheme changed from node-based Green-Gauss gradients to a Least-squares gradient scheme
• Improved both pressure and velocity limiters to help with supersonic and transonic cases.

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release-0.2.0

• Minor modifications to enhance convergence

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release-0.2.1

• Added support for tecplot .szplt output
• Added support for slicing of the final flowfield

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beta

• Implemented incremental back-off in solution update
• Replaced the pressure/density limiters which were edge-based with node-based limiters.
• Improved the stability properties of the solution gradient used for the viscous fluxes.
• Now using a blending of corrected and uncorrected viscous scheme. This effectively limits how much the corrected viscous scheme can differ from the uncorrected scheme. This is necessary because the Jacobian only includes contributions from the uncorrected scheme.
• Bug fix for supersonic farfield boundary condition.