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Preventing Recomputation of Aerodynamic Influence Coefficient Matrices
Hello! In FlightStream are the aerodynamic influence matrices stored in the .fsm simulation file? I've been (unsuccessfully) trying to prevent recomputing them when loading from a .fsm. Is there any way to achieve this? Kind regards, Alfonso
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Mesh best practise FlightStream
Hello, I am having trouble meshing some complex geometrical parts with FlightStream. Are there any best practices to follow when meshing with third-party software, or things I should avoid? Thanks you !
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FlightStream License Error
Product: Flightstream. The license is there and was working fine. Now it's throwing this error. Please help fix it. Note: I am an Auburn University student. I downloaded the 26 version from the Altair website.
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Meshing Nacelle / air inlet on FS
Hello, I am facing some issues while trying to mesh the nacelle / air inlet area on FlightStream. Is there a way to generate a proper CCS mesh for this region? If I decide to mesh this part using a third-party software, how can I connect it with a CCS mesh on the rest of the nacelle? Is it necessary for the mesh surfaces…
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Symmetry plane
Hello, I’m encountering an issue while trying to create the symmetry of my half fuselage. The model was built using a reference coordinate system. I then define a symmetry plane by selecting points on the open face of the fuselage. However, when I mirror the fuselage, the two surfaces do not merge properly and there is a…
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Symetric planes
Hello, When meshing a half model (fuselage + wing) using a symmetry plane, is it necessary to project a CCS curve onto the symmetry plane ? Thanks !
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OpenVSP and FlightStream
Hello, What are the main use cases and advantages of using OpenVSP before setting up a simulation in FlightStream ?
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External Software to mesh
Hello, If a part of my geometry is meshed using external software, what key aspects should be carefully considered ? Thanks !
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Meshing complex bluff bodies
Hello, What is the recommended approach for meshing complex non-lifting geometries such as a rotor hub? Is the TFI mesher appropriate for this type of geometry? Or an external software ? Thanks !
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Meshing the fuselage - wing Area
When merging meshes from two components (e.g., wing–fuselage junction), what are the best practices to ensure a proper connection? How should differences in mesh resolution be handled (e.g., finer mesh on the wing than on the fuselage)? Is it problematic to have highly stretched or anisotropic cells in this region? (like…
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Rotor / hub meshing best practise
Hello, What are the best practices for modeling the rotor hub–blade connection in transient simulations? Should a gap be introduced between the blades and the hub? Is it preferable to remove the hub entirely? Or should a gap be defined between the hub and the fixed geometry while allowing the hub to rotate? Thanks !
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How to access to the FlightStream Youtube Tutorial Videos?
Hi everybody, Could somebody share the tutorial videos that were hosted in Youtube? I recently tried to watch one but the FlightStream account in YouTube was closed. I find these videos extremely helpful, especially since I'm working with undergrad students that are working with FlightStream for the first time. Do someone…
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Pressure contour computed with FlightStream for ONERA M6 wing case
Hi, I tried to load the surface mesh from CFD which is in PLOT3D format. And I ran the case M=0.84, AoA = 3.06 deg with the transonic field panel method. I just ran the case without boundary-layer coupling. The pressure contour does show the Lambda-type shockwave. The surface grid is attached. Not sure whether you can…
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FlightStream Error: GlobalZoneEU Feature Not Found
Hello, I am getting a checkout failure for FlightStream. My Altair License Utility shows that I am "Authorized to use Managed Licensing", but when I launch the app, I get Error Code 9 and Error Code -40 stating that the feature GlobalZoneEU cannot be found at 6200@localhost . I am a student user. I have tried following the…
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Flightstream：Why does the reference velocity have such a large impact on the calculation result Fx?
Dear When I simulated the propeller, the thrust varied significantly with the reference velocity. When I set the velocity to be the same as the free flow velocity, the thrust was smaller than the simulated value. Another issue was that as J increased, the thrust did not decrease as expected, but instead increased.
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Need help with transferring and re-transferring license
Hi, I have a question about my Flightstream Student Edition license. The laptop where I originally installed Flightstream is currently being repaired but I didn't know that I was supposed to deactivate the license first before trying to activate it on another laptop. Is it possible for you to help me with this? Also, I'm…
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How do i model a split flap for a wing in FlightStream correctly?
Hello, i want to simulate a wing with extended split flap on the bottom surface of the wing. I need help in finding the best strategy to set up the simulation in FlightStream. I am not sure what to declare as a base flow region. Its obvious that the blunt trailing edge of the wing and the flap are both base regions but i…
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is coupling between flightstream and Hyperstudy possible for automating the design process?
Hello, I want to explore the feasibility of handling an area rule process using Flighstream. Also coupling between flightstream and Hyperstudy for automating the design process. Please suggest or share relevent material if it is possible.
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FlightStream - Incorrect Moment Coefficients
Hi, I am working on a student project using FlightStream to obtain a full set of stability derivatives for a light GA aircraft, similar in configuration to a Cessna 172. I have been able to produce good results for lift, drag, and side force derivatives, but the pitching, rolling and yawing moments and their associated…
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FlightStream License checkout failed
I'm getting a license error every time I open FlightStream. Please find the attached image. I have tried reinstalling FlightStream, and it did not help. Altair says my license key is still active. Can you please help me fix this error?
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Question about Mesh Convergence for Rotor Geometry
According to the manual, it is recommended to run the analysis with a non-zero angle of attack. For rotors, would it be appropriate to use geometries with varying collective pitch angles for this purpose? Also, in OpenVSP’s detailed settings, the manual mentions setting the clustering values for the leading edge and…
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FlightStream - CCS Wing Meshing Growth Controls Being Ignored
Hi, I have been using the CCS wing meshing tool in FlightStream to create the wings and horizontal/vertical stabiliser for a light aircraft. The mesher works fine without control surfaces, but the moment I specify a control surface it seems to ignore any growth scheme settings. For example, this wing has 160 chordwise…
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Axial Mesh refinement on a fuselage component
I am having problems to refine the mesh on a fuselage component in the axial direction, in the user manual it seems to be possible to do it but the mesh refinement zone tool is only available in the CCS wing tool. Furthermore, i saw that it is possible to use the wrapper tool to refine mesh but it deteriorates the global…
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Inquiry Regarding Tessellation Control in OpenVSP
According to the FlightStream manual, when exporting a rotor from OpenVSP, the values for LE Clustering and TE Clustering should be set to 1. However, there is no specific guidance on how to set the Root Cluster and Tip Cluster values. I would like to inquire about the recommended settings for these parameters.
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FlightStream Publications
This discussion is a running list of FlightStream publications. Our team will routinely update this thread. If you are unsure whether an investigation of interest is available, please reach out to our team directly. Little, D. S., Majdalani, J., Hartfield, R. J., & Ahuja, V. (2025). Improved prediction of propeller tonal…