CFD Results - How to Interpret an Aerodynamic Analysis

Ғылым және технология

For more information on how to process CFD data in paraview (free software):
• CFD Results - How to a...
In this video, we explain how to interpret a typical CFD simulation report. The topic is a car and we will learn how to:
- Understand the different forces & moments
We analyze the drag force, lift force, lateral force as well as the pitch roll and yaw moments. The forces are then used together with the frontal surface area to calculate the drag coefficient of the car.
- Detect sources of drag
The iso-surface of the total pressure for a value of 0 is a good 3D representation of where you are 'losing energy', or dragging air along, or creating a wake. Typically this happens around the wheels, A-pillar, front splitter, door handles, etc.
- Read surface pressure & friction maps
The aerodynamic pressure map provides useful information on where the air is impacting the object, and where it is speeding up to go around curvatures. This can be useful to determine suitable locations for radiator inlet and outlet, to analyze the performance of aerodynamic elements such as rear wings, front splitters, etc.
The friction map can be used to spot areas of flow separation, as low friction usually indicates detached flow (unless it's an area of flow stagnation). The surface streamlines also help to understand the local flow direction.
- Analyse 3D streamlines
Aerodynamic streamlines around the object help to visualize vortex structures, the scope of impact on the surrounding air etc.
- Interpret sections of velocity & pressure
Looking at sections of velocity & pressure helps to understand how the air curves around local parts of the geometry (suspension parts etc), how much it accelerates, what the wake looks like etc.
- Localize sources of wind noise
The results shown are not based on a full acoustic simulation but on an acoustic analogy, which is a mathematical translation of turbulent kinetic energy into noise energy. It doesn't provide the user with any frequency or absolute sound level results, it simply serves as a rough indication of the biggest wind noise sources.
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The AirShaper videos cover the basics of aerodynamics (aerodynamic drag, drag & lift coefficients, boundary layer theory, flow separation, reynolds number...), simulation aspects (computational fluid dynamics, CFD meshing, ...) and aerodynamic testing (wind tunnel testing, flow visualization, ...).
We then use those basics to explain the aerodynamics of (race) cars (aerodynamic efficiency of electric vehicles, aerodynamic drag, downforce, aero maps, formula one aerodynamics, ...), drones and airplanes (propellers, airfoils, electric aviation, eVTOLS, ...), motorcycles (wind buffeting, motogp aerodynamics, ...) and more!
For more information, visit www.airshaper.com

Пікірлер: 122

  • @saibhagavan2008
    @saibhagavan20083 жыл бұрын

    This presentation is as clear as the drinking water we get in our house.....very informative...thanks

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Perhaps you could add an image of the drinking water! You seem healthy and positive, so I'm assuming it's clear 🙂

  • @ganeshnatarajans8129
    @ganeshnatarajans81292 жыл бұрын

    Its one of the best technical interpretation of the obtained CFD results.

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Thank you Ganesh!

  • @lakshmanv4815
    @lakshmanv48153 жыл бұрын

    Hi, presentation was fantastic and look forward to more videos on aerodynamics.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Thank you very much Iakshman, I'm smiling when I read this compliment :) Feel free to check out the other aerodynamics videos on our "Aero Theory" playlist: kzread.info/dash/bejne/dpZ9q9lmh9XfeLw.html

  • @aldairramirez4058
    @aldairramirez40583 жыл бұрын

    First time I see one of your videos. Subscribed!

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Thanks Aldair, I hope you like the other videos we have on the channel!!

  • @michel3892
    @michel38922 жыл бұрын

    What a great channel. Please, make more of theses analisys

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Thank you very much Michel!! We'll continue to push new videos :)

  • @karsolali
    @karsolali3 жыл бұрын

    this is crazy stuff!! thanks :)

  • @michakobylinski9970
    @michakobylinski99703 жыл бұрын

    I am already doing my diploma and this material was very useful, thank you very much :) I already subscribed, hope for more videos

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Thanks a lot Michal, I'm really glad you liked it!!

  • @patelnainesh1326
    @patelnainesh13262 жыл бұрын

    Excellent work..thanks for it

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Thanks Patel!

  • @azadayinmehr7093
    @azadayinmehr70932 жыл бұрын

    amazing. very useful information. thank you.

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Thanks Azad!

  • @user-qv2vh4bw4z
    @user-qv2vh4bw4z3 жыл бұрын

    Awesome, Good Work

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Thanks a lot!!

  • @TravelWidAkki
    @TravelWidAkki2 жыл бұрын

    Thanks for very informative presentation...

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Thank you!

  • @mariusschmoe5514
    @mariusschmoe5514 Жыл бұрын

    Great work Thank you!

  • @AirShaper

    @AirShaper

    9 ай бұрын

    Thanks a lot!! Feel free to also create a free account at app.airshaper.com and check out some sample projects

  • @avery3490
    @avery3490 Жыл бұрын

    Very nice edcational video, I used it to understand the aerodynamics of a cow meme!

  • @AirShaper

    @AirShaper

    Жыл бұрын

    Ah brilliant :D That meme has been around for quite some time - glad the video helped!

  • @raffaelecolombi4999
    @raffaelecolombi49992 жыл бұрын

    Thanks for the nice video! I have a question on something I always find so little information about. In Aerodynamics we use the total pressure coefficient equal 0 (defined a bit differently than the usual pressure coeff) to highlight separation bubbles and wake. Why is that? I mean, what is the physical meaning behind it? Is it like a parameter indicating that for values below zero, the flow has less energy than the freestream? Indicating hence the losses due to recirculation and turbulent wake?

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Hi Raffaele, I recommend reading this article by Willem Toet: www.racetechmag.com/2019/02/willem-toet-explains-cfd-post-processing-part-2/ Indeed, the total pressure is a measure for the energy in the airflow. Keep in mind that the Bernoulli equation is only valid for inviscid flows. In real flows, energy gets lost in the wake for example (as you said), leading to a drop in total pressure (and thus less energy). And loss of energy is a source of aerodynamic drag. So perhaps the volume enclosed by the total pressure below 0 isn't an exact representation of the wake, but rather a representation of energy loss / drag sources. If you want to exactly see the wake, defined as 'the air you drag along in the flow direction', then perhaps you can make an isosurface for the X-component of the velocity equal to perhaps to zero (assuming your object is standing still and the wind flows across the object). That should also be interesting! (We did it before, interesting stuff :) )

  • @EddickC2D
    @EddickC2D3 жыл бұрын

    Finally someone tells the people that aerodynamics is not only about cute colorful images, it is still engineering! :) BTW, tricky question Wouter from my side: if you model the wheels as rotating and the ground as moving towards the car's front with the same velocity as the car's then do you also put BL layer cells on the ground wall(surfc) ? I have heard both approaches, with and without BL cells at the ground but in reality such BL does not exist because the wind is still and the car slices through the air. In CFD case, we "hold" the car and move the air, so do you add these cells? It will always give some different EVR values when BL cells added to the ground, isn't it? Cheers!

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Eddick, thanks a lot for the nice feedback! At the moment, we don't apply prism layer cells and instead we work with wall functions. We're working on it, but as robustness is the number one goal for us, we first need to make sure it can be done properly, even in difficult locations like the wheel-ground interface. Indeed, the ground air is standing still so in theory there is no need for boundary layer cells. What we are thinking of is to just apply them on the part of the ground that is below the car (plus some margin). Because there, you do have a shear stress towards the ground, as the car starts dragging the air along. And around the wheels, you also have a certain 'sphere of influence', so having prism layer cells there would also be good. But getting the mesh and simulation stable is the primary goal, all is slave to that :)

  • @EddickC2D

    @EddickC2D

    3 жыл бұрын

    @@AirShaper Thanks for the answer - it is always about the compromise, as in every branch of engineering :) BTW Do you use also SA turbulence model as it was primarly founded for external aero purposes for aerospace industry or you keep focus on KW-SST with wall funcs ?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@EddickC2D Indeed, always a compromise!! We use the simpleFoam solver with k-omega-SST as a turbulence model with wall functions indeed :)

  • @mickaelblake7088
    @mickaelblake70883 жыл бұрын

    *Thank you, this is very detailed and easily understandable* ! - By the way, the interpretation of the aero analysis of a teardrop car with 3 covered wheels and extremely low to the ground would show extremely low surface pressures right ?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    The surface pressure doesn't need to be low everywhere to have low drag. It's the 'nett' pressure sum across the entire surface that determines the total drag. That means you can still have some pressure increase at the front qs long as you 'recover' that pressure at the back (which requires nicely attached flow, no separation). Even the most streamlined shapes have a stagnation point somewhere at the leading edge.

  • @mickaelblake7088

    @mickaelblake7088

    3 жыл бұрын

    So if an Object has an attached and laminar air flow around it with almost no turbulence, it has a low drag coefficient ?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    On average, yes. But it depends on Reynolds number, fluid properties, and so on!

  • @mickaelblake7088

    @mickaelblake7088

    3 жыл бұрын

    @@AirShaper Thank you for the explanation !

  • @miro1miro
    @miro1miro2 жыл бұрын

    Hello Wouter! For this simulation, which turbulence model did you use? How many layers of elements were placed in the vehicle's boundary layer? What is the maximum Y+ of the first layer of elements surrounding the vehicle? If a plane of symmetry was used, could one get the same results? Why did you choose hexahedra instead of polyhedra for the mesh? Thank you

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Hi Henrique, we used a k-omega SST turbulence model to run a steady state simulation. We didn't apply prism layers and used wall functions instead. I don't have info on the Y+ values (they vary across the surface), but you can check this sample project and then download the sample data and check it yourself if you like: app.airshaper.com/projects/sample/sports-car We use hexa cells for the "main" mesh as this limits some of the discretization errors, and close to the surface, the mesh is cut & snapped to the surface (we use snappyHexMesh). Hope that answers your questions!

  • @miro1miro

    @miro1miro

    2 жыл бұрын

    Hello Wouter, thank you for the answers! The presentation is great too! Best regards

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    @@miro1miro You're most welcome!

  • @PARTHESUNDSEC
    @PARTHESUNDSEC9 ай бұрын

    sir i have one question what is the range value that aerodynamics or cfd actually need ....like if my vehicle aero resistance is 90N means then we have to put cfd or not??? velocity of our vehicle is 16.67m/s ( its an electric atv sir ) so how we should decide that ?

  • @mohamedabdelmaksod660
    @mohamedabdelmaksod6603 жыл бұрын

    thanks a lot for this informative video, i appreciate it if you would tell the mesh cell type you used in your simulation (tetra or Hexa or mixed between them?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Mohamed, thanks a lot! It's a hex dominant mesh with non-hexagonal cells close to the surface. We use snappyHexMesh (the mesher provided in OpenFOAM).

  • @mohamedabdelmaksod660

    @mohamedabdelmaksod660

    3 жыл бұрын

    @@AirShaper but why non hexagonal cells close to surface specifically? I would suggest if you can make a video on meshing best practices for aerodynamics simulations Thanks again for your help

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@mohamedabdelmaksod660 snappyHexMesh cuts them around the surface and then snaps the "remaining" parts to the surface. More info here: cfd.direct/openfoam/user-guide/v6-snappyhexmesh/ As we have automated the meshing at AirShaper, we don't provide options for custom meshing. But we do have a video on how to "chose" between different mesh resolutions - I hope that one is at least partially useful for you: airshaper.com/videos/choosing-your-simulation-accuracy-vs-speed-vs-cost/video/Evxpkwjb5dQ

  • @yunsulee4736
    @yunsulee4736 Жыл бұрын

    Very nice video! So separation of air means no pressure in that area?(the red part in 3d pressure cloud, where Cp = 0)?

  • @AirShaper

    @AirShaper

    9 ай бұрын

    Cp = 0 does not mean there is no pressure - this is the total pressure in a simulation where the atmospheric pressure is not included (so the "reference pressure" is zero). Cp = 0 is an interesting iso-surface, as it shows the 3D volumes inside which you are loosing energy (because total pressure in a way represents this).

  • @SkywalkerXXL
    @SkywalkerXXL3 жыл бұрын

    Very cool to see, I hope I can somehow simulate my own car and play with it's aerodynamics. Gotta get a 3D model somewhere :)

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    That sounds cool indeed, just let me know when you have that 3D model, then we can help out!

  • @pa_blo4220
    @pa_blo42203 жыл бұрын

    Very nice video! I have a question about adding wind skirts upstream of the tires: wont the skirts create their own pressure drag?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Pablo, do you lean the small flaps, or air deflectors, just ahead of the tires? If yes, then indeed, on their own they create extra drag. But they create a wake that shields the tires, reducibg the drag on those. If the reduction in drag on the tires is higher than the extra drag on the deflectors then the nett result is lower drag.

  • @giuseppetorre1537

    @giuseppetorre1537

    3 жыл бұрын

    As @AirShaper stated, in the automotive sector (expecially motorsport) it's always a trade off, for example in F1 they use a big vortex line y=250 to shield the undertray

  • @pa_blo4220

    @pa_blo4220

    3 жыл бұрын

    @@AirShaper @Giuseppe Torre I was indeed talking about the deflectors ahead of the tires. Thanks for your reply! Makes sense.

  • @nebulous962
    @nebulous9623 жыл бұрын

    very intresting🤔

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Thanks a lot!!

  • @anaskhan97
    @anaskhan973 ай бұрын

    Hi, Great presentation, it was really helpful. Can you do a video on how you prepare CAD models of cars specifically for CFD simulations?

  • @AirShaper

    @AirShaper

    3 ай бұрын

    Thank you! Are AirsShaper, the preparation time is limited as it works with non watertight 3D models, up to 3GB in size and no need to simplify (up to 10.000 components). But generally yes, you're best to clean up the cad, make it closed, prepare the contact patches of the wheels, simplify radiators, ...

  • @CesarLopez-qt9mo
    @CesarLopez-qt9mo3 жыл бұрын

    Hi sir. Firs of all thank you for the presentation it is pretty illustrative. I have a questions, how do you transform TKE to noise energy? Which model are you using?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Cesar, thanks for the compliment! We use the Lighthill acoustic analogy - it's a public formula you can apply yourself!

  • @CesarLopez-qt9mo

    @CesarLopez-qt9mo

    3 жыл бұрын

    @@AirShaper Thank you very much. I am beginning on noise modeling for industrial flows this far I was know that just LES or DES are used to middling but I was not aware of those analogies that may fit better in terms of simulation time. Thank very much.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    You're welcome Cesar. Keep in mind that this analogy is a simplifief approach which won't provide frequency information or perceived noise at a certain location. But it's very good as a first assessment on the location of noise sources. Good luck!

  • @hemantpandey9676
    @hemantpandey96762 жыл бұрын

    I have few doubts.. Please help me ! How can I determine the Characteristic Length of a car with its windows open for external CFD analysis in order to determine the drag force ? Also, what y+ value would you recommend in that case if k-w SST turbulence model is used ?

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    For a car, the characteristic length is typically the length of the car itself. But keep in mind that this is always subjective and doesn't represent a real physical quantity (see our video on Reynolds Number: airshaper.com/videos/the-relation-between-turbulence-reynolds-and-wind-tunnel-testing/sV8l8xd4MEQ). In terms of y+, when using a turbulence model, it is often advised to have y+ between 30 and 100.

  • @hemantpandey9676

    @hemantpandey9676

    2 жыл бұрын

    @@AirShaper Thanks Airshaper ! This will really help me to proceed further in my simulation . One more thing I would like to know that how do you determine the appropriate size of a virtual wind tunnel ? Is there any rule of thumb to determine the optimum size of VWT ? Since, as the size of a VWT increases , the number of elements in our mesh also increases , which implies longer computational time . And this becomes important particularly for students like me who don't have access to high performance computers . By the way , thanks one again !

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    ​@@hemantpandey9676 increasing the size of the tunnel helps to keep the blockage factor & wall effects to a minimum (see this video: airshaper.com/videos/scale-model-wind-tunnel-testing/qqYiz1eo-F4). As it's a virtual tunnel, the cost of increasing the size is quite low, especially because you can use coarse cells for the outer parts of the tunnel. We typically aim for a blockage factor of 1% at AirShaper. But a VAWT is a very "airy" design, so additionally I would also aim to stay well away from the walls. Perhaps this paper can be interesting: pdf.sciencedirectassets.com/271422/1-s2.0-S0167610518X00063/1-s2.0-S016761051730702X/am.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEO%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIQCNBx%2B%2FjQmBf6py3uvwDhNo9iXCupLn%2F%2Bcy%2FfYGdjJ64AIgdb7723fv15OvzfBLnkqxXYy6utHTLYjkSrVbd8qDxtEq%2BgMIWBAEGgwwNTkwMDM1NDY4NjUiDGpn6aMOKOJwJGti5CrXA%2FK48kspBMu72CgrT5MhOmJxHjoRWjoR548YEkFnRuqnmRXblAo9S3Ikcd3%2FLlVOg0Ce5AmVxDhu20X0P7f5cdn%2BPfxzBbbIeZWXduzlmowImfgJVWmH%2F32wnl0sW1moeXUnVirggxU1Lu7DkTKGLXasXsYgp2tSQpMdbdoo3qPli%2BfeQMaSOYaQ%2FbUzKllaS%2F0M5vfq8O5PrHpmIzo0KAnlP65wyWD6d4azVqzys0KvYv%2BToS4RZvVvxLtZc73W56wIHtMyQIr5xfEo4NQVO3fPmJBKZF4AbHrRZHpOUHK7BQqyXfpkuRQEx1Ds3rbyQHmvkAUHS7MImGkLnDTcmBQMgokxIMIipdiouCA2LcYUhsiKz6XrcuaBQERKKYDcL4NCKbwhmUraf0m42WazB57k9HvBedSMNK1JpSfMPoMugYgUvi20OtQg7Zq14cHs3P59Ao8KQX5Im9h6h5PtylAO5kIZDc2JF1wq9EQ8F2R3KsRUJcT9e7ASVco5Rt8wG16fBNrs7kMhQko2LHAqs%2FsUVFJrPmgnA%2BoStVAz5L9FSjVWuNqb2XsHagiFw3sXPrXrVKpz4YyxX8xB8g3ja7i9Hg6%2FH6RUZgXHnT%2BWP5UxLmHbH5uCsDDV6YaRBjqlAXiA84cRn5HS%2FX%2BKiFslE4jPO0%2BJSpld%2FxZBe%2FbrBGK4MhCL6XTLqohZaz2NRXC3bZNApAStRjA6x1X22bNTPRfLcZ9ufzenP0Z1LOp6%2FvrQSKY9HHYtL4RCO%2BsQk6HZGCP7LEdX2LvAe3j%2BPAOtg14J1cOo4NnbMTWHy26kSMAMYGtLdAmC1rlNpEOujl%2BGXdsP%2FfVS5uowCyjgol0eYn33CTePiQ%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20220304T074000Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYVY6LGHGJ%2F20220304%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=6b9f7abd07fd79a3332e6f99f27c9a36dec4fd6b8da851bf25e528c748f59c08&hash=43c5be083dc84b60e55481de3f2c48206a4efe0a6168ce86d3d100303da452c3&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S016761051730702X&tid=pdf-802dc23c-e5b6-4a9d-93a8-c37c6d7cfc10&sid=9acaff934353b74e3368f5a46ff93a4f80cbgxrqb&type=client

  • @hemantpandey9676

    @hemantpandey9676

    2 жыл бұрын

    @@AirShaper Yeah.. I got it . Thanks AirShaper !

  • @nebulous962
    @nebulous9623 жыл бұрын

    5:57 would having only one front wheel help with that? I am trying to build kinda small 3 wheel ev so that's why i am asking (speed about 25-50kph) also does aerodynamics matter at these speeds ?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Yes, aerodynamics definitely matter at those speeds! When cycling at30 kp/h for example, already more than half of the energy is spent on aerodynamics. We did a video on the aerodynamics of a low-speed city vehicle: airshaper.com/videos/smart-mobility-city-vehicle-aerodynamics/video/mp-yl8wwEz0 Having just one front wheel could indeed reduce aerodynamic drag. But it would influence the entire underfloor aerodynamics of the vehicle, so you may need to rethink the bottom floor as well (to cope with the flow coming off the front wheel). Feel free to drop me a line at wouter@airshaper.com if you want to run a simulation on your model (if you have a 3D model already)!

  • @nebulous962

    @nebulous962

    3 жыл бұрын

    @@AirShaper I don't have 3d model yet , but i appreciate the help :)

  • @nebulous962

    @nebulous962

    3 жыл бұрын

    i mean it needs alot of flat roof surface because i want to make it all solar powered but that's pretty much all i know so far :D

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@nebulous962 Ah, then be sure to check our interview with Lowie Vermeersch on how they helped design the Lightyear One Solar Powered Car: airshaper.com/videos/lowie-vermeersch-2-the-lightyear-one-solar-car/video/TKHjyC_L0OM

  • @nebulous962

    @nebulous962

    3 жыл бұрын

    thanks

  • @itapsi229
    @itapsi2292 жыл бұрын

    i had a few questions, what analysis should i presentation for flying object cfd? and what ideal value for (ex : velocity, pressure, etc). Thanks

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    For pressure we often use the stagnation pressure as a limit for the scale (0.5 * rho * v²). But in general, it depends greatly on which aspect you want to analyze (lift, drag, efficiency, ...). Perhaps you can check our videos on drone design as well: i.ytimg.com/an_webp/kAXN3MlQxxc/mqdefault_6s.webp?du=3000&sqp=CPqs6JMG&rs=AOn4CLDSLfaEPxCTY5Tr-p7LRdZMqdpuig kzread.info/dash/bejne/eI58u8WqgsaqerA.html

  • @aldairramirez4058
    @aldairramirez40583 жыл бұрын

    Not sure if it's within the scope of the channel, but a meshless cfd video would be nice

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Thanks for the suggestion Aldair!

  • @robcad
    @robcad2 жыл бұрын

    Can I ask question about condition velocity at 50 m/s ? What is reason or some idea that why we should compare each model with V=50 m/s . Thanks for advanced .

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    The choice for 50 m/s was completely arbitrary for this simulation. Typically, you would select either the top speed (when optimizing for top speed), the average speed around a track (when optimizing for lap times) or the average driving speed across for example the WLTP (when optimizing for vehicle emissions).

  • @danielgeno6624
    @danielgeno66243 жыл бұрын

    i think i have a bad airflow design on a mass product, would you like to take a look at the picture and tell me if im wrong?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Zelda, yeah you can send the images and a description of the project to info@airshaper.com and I'll have a look!

  • @JayTheMachine
    @JayTheMachine3 жыл бұрын

    What software you used to conduct CFD simulation, I prefer abaqus and ansys.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Jay, Abaqus and Ansys are definitely good packages. We use OpenFOAM, which is a well-known & validated open-source environment for CFD simulations.

  • @JayTheMachine

    @JayTheMachine

    3 жыл бұрын

    @@AirShaper thank you I will try it, looks amazing. And I have a question, did you engineered the vents of the car in this video? Like by applying formulas of Fluid dynamics or you simply designed it for sort of fun without getting into FD and engineering side. Just curious coz simulation was amazing.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@JayTheMachine Hi Jay, I designed those channels to generate lateral forces. I actually didn't know CFD when I did that, but it's the reason I got into it later on. You can read more about it on this page: www.airshaper.com/cases/aquilo-patented-aerodynamic-concept-car

  • @robtomben
    @robtomben3 жыл бұрын

    Hello. Can you help settle a bet? My friend said his roof racks on his car generated enough drag to noticeably affect his mpg on the highway. He estimated 3 to 5 mpg less than without racks. I told him I thought that sounded reasonable. Another friend thought this seemed unlikely. Now we have ourselves a wager. Is it reasonable to assume that normal type roof racks could have that much affect?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    That sounds realistic! Depends on loading, position, size, ... of the rack, but this could perhaps increase drag by 10%, which would increase fuel consumption by 5-7% depending on the driving speed. That could indeed translate into a 3-5mpg difference. You can do a top speed test with and without the rack on a track. With some calculations, you can then estimate the drag difference!

  • @robtomben

    @robtomben

    3 жыл бұрын

    @@AirShaper Thanks so much!

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hope you earned something 🙂

  • @robtomben

    @robtomben

    3 жыл бұрын

    @@AirShaper I have learned quite a bit from your channel. (I earned a dollar from winning the bet) However at the moment I am building small fixed wing drones from scratch. Attempting to maximize efficiency and flight characteristics using Vehicle Sketch Pad (VSP). Hopefully someday I'll have the resources available to use AirShaper during design!

  • @Poduhvat
    @Poduhvat2 жыл бұрын

    How do you transfer turbulent kinetic energy into noise levels, I did search and I had not find any formula?

  • @AirShaper

    @AirShaper

    2 жыл бұрын

    Hi Nenad, we use an acoustic analogy (based on Lighthill / Proudman): www.afs.enea.it/project/neptunius/docs/fluent/html/th/node237.htm Hope it helps!

  • @Poduhvat

    @Poduhvat

    2 жыл бұрын

    Thank you.

  • @megacup3977
    @megacup3977Ай бұрын

    is tere a free versuin?

  • @brianwashingtonmusungwa7567
    @brianwashingtonmusungwa7567 Жыл бұрын

    Hi thanks for the video Can you help with CAD model ?

  • @AirShaper

    @AirShaper

    9 ай бұрын

    We don't do CAD modeling but feel free to contact us at info@airshaper.com if you have more questions!

  • @user-wm1ku2bt4c
    @user-wm1ku2bt4c3 жыл бұрын

    Which software are you using for this

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    We use a highly modified OpenFOAM environment. If you want to learn OpenFOAM, feel free to check out our old course material at www.airshaper.com/courses Good luck!

  • @ahmetkirhan5896
    @ahmetkirhan5896 Жыл бұрын

    Hello Sir, When you say "wake behind the car" in 7:19 , what do you mean by saying "wake" ?

  • @AirShaper

    @AirShaper

    Жыл бұрын

    By wake I mean the volume of air which is being dragged along. Does that make sense?

  • @ahmetkirhan5896

    @ahmetkirhan5896

    Жыл бұрын

    @@AirShaper let me put it this way if its right, the volume of air that has been effected by the car at a moment of time

  • @AirShaper

    @AirShaper

    Жыл бұрын

    @@ahmetkirhan5896 a lot of the air around the car is affected, but the wake is that part where air is being dragged forward (opposed to the rest of the air passing without too much change in momentum)

  • @ahmetkirhan5896

    @ahmetkirhan5896

    Жыл бұрын

    @@AirShaper oh okay, Sir. Thank you so much for the explanation :)

  • @paulstephen7225
    @paulstephen72253 жыл бұрын

    What are the conditions needed to perform boolaen operation in ansys fluent? Thank you in advance.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hello Paul, we work with OpenFOAM at AirShaper. I don't know how to do that in Fluent.

  • @paulstephen7225

    @paulstephen7225

    3 жыл бұрын

    @@AirShaper Ok thank you for your reply

  • @paulstephen7225

    @paulstephen7225

    3 жыл бұрын

    @@AirShaper Is rear diffuser an integral part of all car?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@paulstephen7225 It's often a stand-aline part that is added to the car. But in terms of design & aerodynamics, it indeed interacts with many other aspects of the car.

  • @tobiasobermayr501
    @tobiasobermayr5013 ай бұрын

    is there only 500 Pascal max. of extra pressure on the front of the car? Isn't the pressure there much much higher?

  • @AirShaper

    @AirShaper

    3 ай бұрын

    The max pressure (relative to the environment pressure) is usually the stagnation pressure, i.e. 0.5*density*velocity^2

  • @tobiasobermayr501

    @tobiasobermayr501

    3 ай бұрын

    ​@@AirShaper okay, just read up it's way more pressure than I thought. Am new to the subject, so thanks for explaining.

  • @oskki224
    @oskki2243 жыл бұрын

    Why not use symmetry plane in this case?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Good comment! Yes, that would have been possible here. But it is not exactly the same as a full model (you eliminate lateral glow oscillations) and when we open/close internal channels asymmetrically, we'd need a full model again and we'd be comparing different meshes.

  • @sebastienricciardi883
    @sebastienricciardi8833 жыл бұрын

    Are the wheels rotating ?

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Not in this simulation if I remember correctly, but we do have that functionality (both tangential velocity and MRF). Are you looking to run such a simulation?

  • @sebastienricciardi883

    @sebastienricciardi883

    3 жыл бұрын

    @@AirShaper we have mesh issues to fix first but ultimately yes

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@sebastienricciardi883 Hi Sebastien, ok cool I'm curious to see the model! Keep in mind that AirShaper can work directly with open surface models (non-watertight geometry). So if you're referring to that issue, there is no need to prepare models for AirShaper. Just drop me an email at wouter@airshaper.com if you need more info!

  • @nesmio7378
    @nesmio73783 жыл бұрын

    You doing videos like this are so much lighter and more interesting to watch compared to you reading of a script with a bunch of info in it, it makes it very heavy, dense and tbh at the end of the day bland and boring. It is much more interesting you just being you trying to explain things.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    Hi Nesmio, do you mean it's better in this video (me talking while showing stuff) or better of I stand in front to explain stuff? Thx for the honest feedback!

  • @nesmio7378

    @nesmio7378

    3 жыл бұрын

    @@AirShaper It is better in this video when you are just free flowing and being natural instead of in my personal opinion the super forced in-front of camera presentations.

  • @AirShaper

    @AirShaper

    3 жыл бұрын

    @@nesmio7378 Thanks Nesmio, I do need to practice & record multiple times for the in-front camera presentations :)

  • @nesmio7378

    @nesmio7378

    3 жыл бұрын

    @@AirShaper No problem, I love your videos and presentations with the information in them, they are just a bit awkward to watch a lot of the time, this though was perfect! Keep it up.

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