Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-31-2022, 09:18 PM   #21 (permalink)
Master EcoModder
 
Phase's Avatar
 
Join Date: Mar 2022
Location: oregon
Posts: 1,121

Black Bullet - '19 Hyundai Ioniq Hybrid Blue
Thanks: 1
Thanked 592 Times in 470 Posts
Quote:
Originally Posted by freebeard View Post
For those following along at home : hypereconiq image and link
the rear spoiler doesnt make much sense to me though. it increases the wake area. if anything, it should slope down lower to reduce the wake, then flip up at the end, without going above the height of the original wake area line

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-01-2022, 08:50 AM   #22 (permalink)
Long time lurker
 
AeroMcAeroFace's Avatar
 
Join Date: May 2019
Location: Uk
Posts: 218
Thanks: 110
Thanked 153 Times in 119 Posts
Quote:
Originally Posted by Phase View Post
the rear spoiler doesnt make much sense to me though. it increases the wake area. if anything, it should slope down lower to reduce the wake, then flip up at the end, without going above the height of the original wake area line
I can't comment on the specifics because I have never seen that vehicle, but it is always possible that the increased wake area and differing recirculation actually reduces drag.

By increasing the height of the rear spoiler it may reduce drag from the underside, increase flow under the car, reduce drag at the corners where the side meets the back etc.

Last edited by AeroMcAeroFace; 04-01-2022 at 11:14 AM.. Reason: adding etc. there are many reasons that I didn't mention, due to space and knowledge limitations.
  Reply With Quote
Old 04-01-2022, 09:18 AM   #23 (permalink)
Moderator
 
Vman455's Avatar
 
Join Date: Feb 2012
Location: Urbana, IL
Posts: 1,939

Pope Pious the Prius - '13 Toyota Prius Two
Team Toyota
SUV
90 day: 51.62 mpg (US)

Tycho the Truck - '91 Toyota Pickup DLX 4WD
90 day: 22.22 mpg (US)
Thanks: 199
Thanked 1,804 Times in 941 Posts
Quote:
Originally Posted by AeroMcAeroFace View Post
I can't comment on the specifics because I have never seen that vehicle, but it is always possible that the increased wake area and differing recirculation actually reduces drag.

By increasing the height of the rear spoiler it may reduce drag from the underside, increase flow under the car, reduce drag at the corners where the side meets the back.
Exactly--there's much more going on than wake area. The flow around cars is three-dimensional, complex, and not possible to predict using simple principles. This isn't me arguing this; look in any textbook. For example, RH Barnard, 2009: "There are no straightforward methods for predicting how air will flow around a given shape." It's literally on the first page of the book!

A spoiler can also reduce drag and lift by increasing pressure on the surfaces ahead of it.
__________________
UIUC Aerospace Engineering
www.amateuraerodynamics.com
  Reply With Quote
The Following User Says Thank You to Vman455 For This Useful Post:
AeroMcAeroFace (04-01-2022)
Old 04-01-2022, 01:06 PM   #24 (permalink)
Master EcoModder
 
Phase's Avatar
 
Join Date: Mar 2022
Location: oregon
Posts: 1,121

Black Bullet - '19 Hyundai Ioniq Hybrid Blue
Thanks: 1
Thanked 592 Times in 470 Posts
I’m also shocked they didn’t use any aero wheel covers. Yeah they carbon fiber wheels look nice and shiny, but in terms of aero, there’s no way they are helping
  Reply With Quote
Old 04-01-2022, 01:23 PM   #25 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 28,541
Thanks: 8,084
Thanked 8,877 Times in 7,326 Posts
Someone posted it and I've already forgotten which one, but a recent concept car has a concave spoon-shaped depression ahead of the spoiler to add downforce without increasing the drag.

Search function isn't helping.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
.
.
Three conspiracy theorists walk into a bar --You can't say that is a coincidence.
  Reply With Quote
Old 04-01-2022, 04:37 PM   #26 (permalink)
Master EcoModder
 
Phase's Avatar
 
Join Date: Mar 2022
Location: oregon
Posts: 1,121

Black Bullet - '19 Hyundai Ioniq Hybrid Blue
Thanks: 1
Thanked 592 Times in 470 Posts
The two main things I thing would be easiest to do would be to make a smooth undertray ( girlfriends mom is a professional welder so it shouldn’t be too hard) and then a rear wheel spat that looks cool and OEM and could be removable. I’d also like to someone make the back of the car have a box cavity type styling with the edges going slightly inwards to reduce the wake. Not going to go the full boat tail route for practical reasons.
  Reply With Quote
The Following User Says Thank You to Phase For This Useful Post:
freebeard (04-01-2022)
Old 04-01-2022, 04:50 PM   #27 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 28,541
Thanks: 8,084
Thanked 8,877 Times in 7,326 Posts
It comes down to how the bellypan and difusser transition into the boxed cavity.

I saw this at Bonneville Salt Flats:



I could've got a better angle but I never saw it again. The skegs flare out from inside the tire to flush with the outer face. I think this would keep the turbulence in the wheelwell from migrating into the underbody flow, and provide fencing to the difusser.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
.
.
Three conspiracy theorists walk into a bar --You can't say that is a coincidence.
  Reply With Quote
Old 04-01-2022, 05:26 PM   #28 (permalink)
Master EcoModder
 
Phase's Avatar
 
Join Date: Mar 2022
Location: oregon
Posts: 1,121

Black Bullet - '19 Hyundai Ioniq Hybrid Blue
Thanks: 1
Thanked 592 Times in 470 Posts
Quote:
Originally Posted by freebeard View Post
It comes down to how the bellypan and difusser transition into the boxed cavity.

I saw this at Bonneville Salt Flats:



I could've got a better angle but I never saw it again. The skegs flare out from inside the tire to flush with the outer face. I think this would keep the turbulence in the wheelwell from migrating into the underbody flow, and provide fencing to the difusser.
yeah i definitely need to do a smooth belly pan and rear diffuser first before i do the other more difficult mods
  Reply With Quote
Old 04-01-2022, 05:28 PM   #29 (permalink)
Master EcoModder
 
Phase's Avatar
 
Join Date: Mar 2022
Location: oregon
Posts: 1,121

Black Bullet - '19 Hyundai Ioniq Hybrid Blue
Thanks: 1
Thanked 592 Times in 470 Posts


heres the porsche 935. the box cavity looks amazing. plenty of other images online too
  Reply With Quote
Old 04-02-2022, 10:44 AM   #30 (permalink)
Moderator
 
Vman455's Avatar
 
Join Date: Feb 2012
Location: Urbana, IL
Posts: 1,939

Pope Pious the Prius - '13 Toyota Prius Two
Team Toyota
SUV
90 day: 51.62 mpg (US)

Tycho the Truck - '91 Toyota Pickup DLX 4WD
90 day: 22.22 mpg (US)
Thanks: 199
Thanked 1,804 Times in 941 Posts
Quote:
Originally Posted by Phase View Post
The two main things I thing would be easiest to do would be to make a smooth undertray ( girlfriends mom is a professional welder so it shouldn’t be too hard) and then a rear wheel spat that looks cool and OEM and could be removable. I’d also like to someone make the back of the car have a box cavity type styling with the edges going slightly inwards to reduce the wake. Not going to go the full boat tail route for practical reasons.
Those all sound like a good starting point. Build them out of cheap, disposable materials first and test them. Every time I test, I am surprised at what works that I didn't think would work, and what doesn't work that I really thought would.

__________________
UIUC Aerospace Engineering
www.amateuraerodynamics.com
  Reply With Quote
The Following User Says Thank You to Vman455 For This Useful Post:
COcyclist (08-18-2022)
Reply  Post New Thread






Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com