View Single Post
Old 12-11-2019, 12:07 AM   #1 (permalink)
Ecomodding amateur
M_a_t_t's Avatar
Join Date: Nov 2015
Location: Indiana
Posts: 326

The Van - '95 Chevy Astro Cl
Team Chevy
90 day: 16.39 mpg (US)

The new bike - '17 Kawasaki Versys X 300 abs
90 day: 64.78 mpg (US)

The Mercury - '95 Mercury Tracer Trio
Team Ford
90 day: 33.79 mpg (US)
Thanks: 53
Thanked 117 Times in 85 Posts
Help me evaluate CFD results

I have been playing around with a model of my car and putting it in a cfd program. The model is not that great, however it is pretty accurate (shape wise) from the center line of the car. Based on this I have been messing with the angle of the hood to windshield and the nose. I have a limited understanding of how the numbers should be interpreted and would like more opinions on the subject. Rather than posting a bunch of screen shots directly here I have inserted them in a google document.

(quick sample)

The program I used for modeling is Autodesk Inventor and the CFD is Autodesk Flow Design.

The wind speed is set to 10 m/s (I forgot to increase it) unless otherwise noted.

The 2d plane the pressure is mapped on is in the same spot for all screen shots.
  • The car is not sitting on the ground plane, would this effect how to interpret the front and top of the car?
  • I had two options for mapping, pressure or velocity. Is one better to look at or is it a combination of the two that makes the data interpretable?
  • Is there anything that you guys suggest I try and mock up and test?
  • The first thing I wanted to test was the simple hood height (because of visibility and simplicity), the only differences I see is a lower high pressure (on the scale) and a more localized section of low pressure where the windshield and the roof meet. Also something different is going on with the underside, not sure if its because of the adjusted scale or it somehow affected the undercarriage.

Thank you in advance,

My herd includes:
1973 Fiat 124 Special
1975 Honda Civic CVCC 4spd
1981 Kawasaki KZ750E
1981 Kawasaki KZ650 CSR
1983 Kawasaki KZ1100-A3
1986 Nissan 300zx Turbo 5 spd
1995 Chevy Astro RWD
1995 Mercury Tracer
2004 Chevy Astro AWD
2017 Kawasaki VersysX 300
  Reply With Quote