Jump to content
SAU Community

Uas 300Zx Vs. Standard 300Zx Aero Analysis And Results

Boosted Zed
 Share

Recommended Posts

Boosted Zed Mentor

Boosted Zed

Posted
Posted

UAS has recently begun using Computational Fluid Dynamics (CFD) software to aid us in designing elements of our aerodynamics package.

Unforunately time and cost constraints make a true to life simulation a difficut task to achieve, as ideally every component down to the smallest washer should be modeled into the software and then animated to garner accurate results.

STANDARD CAR

FULL CAR SIMULATION

The above two videos show the flow trajectories over the UAS Zed and a standard 300ZX respectively. Though the models are rough they are enough to indicate significant changes in aerodynamic downforce and drag. The figures in the above simulations showed the UAS Zed generated five times more downforce than the standard 300ZX at 200km/h.

To give the exact measurements that is an increase from approximately 50kg to almost 280kg. Drag also increased but only by a factor of two with the standard car measuring 100kg of downforce to the UAS car's 230kg.

The UAS rear wing is a fantastic example of how we use the software to aid our design despite our time constraints. By focusing on a small area in isolation, we can more clearly judge how changes will impact our drag and downforce characteristics.

REAR WING

In this instance it was found that adding a 15mm gurney strip to the larger lower rear wing increased the overall downforce by a significant amount ( ≈ 11%). This produces an extra 14kg of effective weight on the rear at 200kph, with only ≈3% increase in total rear wing drag.

We have also been able to generate numerical data using the program. Doing so allowed us to find a number of interesting results.

On straights, the wear wing of the UAS Zed has a tendancy to flex under the downforce load. This change in area has an impact on the overall downforce of the wing.

circuit_battle.jpg

Using CFD analysis we were able to simulate a number of different instances. We simulated a straight wing, one with the top wing flexing to touch the lower and an instance of both flexing to the same degree. We did this at both 200km/h and 100km/h simulating a worst case scenario through high and low speed corners.

As can be seen from the tabulated data this flexing causes a drastic change in the dynamics of the wing. Both downforce and drag are significantly reduced as the wing starts to bend.

graph.jpg

On straights this is beneficial as it has the same effect as the adjustable rear wing systems used in the 2011 formula 1 season, if to a lesser degree, reducing drag so we can achieve a higher top speed.

In low speed areas it is slightly more detrimental, however it should be noted that at these speeds overall downforce is significantly lower and as such flex is reduced causing a corresponding reduction in overall downforce lost.

  • 4 weeks later...
  • 1 month later...
  • 2 weeks later...
Boosted Zed Mentor

Boosted Zed

Posted
  • Author
Posted

what is the wing made of/? that is some serious flex

Carbon fibre epoxy resin with sandwich foam core. It flexes because it has 200+kg downforce.

We recently added an aluminium right angle gurney strip to the trailing edge of the main rear wing blade. This will stiffen it up a little bit, although the flex is not all bad as it creates maximum efficiency at low speed where it needs it most. At high speed as it bends it reduces efficiency but also less drag.

  • 1 month later...
  • 2 months later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • LegendGTR
      EFR7670 exhaust selection RB26

      By LegendGTR · Posted

      I'm looking for some real world experiences/feed back from anyone who has personally ran a EFR7670 with a 1.05 exhaust housing or a .83 I'm leaning towards the .83 because its a street car used mostly for spirited driving in the canyons roads. I"m not looking for big numbers on paper. I want a responsive powerband that will be very linear to 8000 rpm. I dont mind if power remains somewhat flat but dont want power to drop off on top. The turbo I've purchased is a 1.05, although the mounting flange T3 vs T4 and internal vs external waste gates are different on both housings, I not concern about swapping parts or making fabrication mods to get what I want. Based on some of the research I've done with chat gpt, the 1.05 housing seems to be the way to go with slightly more lag and future proofing for more mods but recommends .83 for best response/street car setup. AI doesn't have the same emotions as real people driving a GTR so I think you guys will be able to give me better feed back 😀   
    • PranK
      Stock Airbox and Snorkle for RWC - VIC west

      By PranK · Posted

      Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • PranK
      Duncan's V37.......race car?

      By PranK · Posted

      This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
×
×
  • Create New...