How to do pics of tuft testing

[M_a_t_t]

I also remade the modified GIF. Much easier to look at.



Now for my armchair analysis, let me know how agreeable it is. It appears to be working, atleast better than the stock version. The part on the bumper is angled too sharply and/or because of the spinning wheel and is getting early separation as a result. The lower half shows this because it is flat against the body at the top. The upper half by the tail light seems to be working the best, but possible interference from the rounded trunk edge and wing. Tufts 2 and 3 (from the top) are what I should try to get all the tufts to do.

[MetroMPG]

I've shot video of tuft tests on numerous cars by mounting a small camera on a boom that's attached aft of the area being filmed (obviously to minimize aero interference from the camera rig).

3 examples:


1) 2000 Honda Insight

https://www.youtube.com/watch?v=TmEeiGZwmS8

From thread: MetroMPG's Honda Insight boat tail extension (cardboard) tuft video; ABA test +9.7%

The cord tied between the two booms adds tension to prevent the camera from bouncing.

2) Similar set-up on my 2nd gen 2004 Toyota Prius:

https://www.youtube.com/watch?v=03vLhpPKAgE

From thread (starting around post #100): The Premier's Limo: 2004 Toyota Prius "winter beater" ecomodding thread

3) And the current car (1990 Miata MX5) - I didn't get a shot of the camera boom itself, but in this case it was a rigid DIY tripod of aluminum tubing, liberally duct taped to the rear & side of the car:





From thread: "MPGiata" modding thread: aiming for 50 MPG with a 1990 Miata. Update: success, 55 MPG


The other two tripod legs are out of the frame.

---


Cameras with wider angle lenses are better because you can use a shorter boom (Prius boom is probably 1/2 the length of the Insight's).


Obviously this approach is only practical/safe if the road you test on is free of obstructions/pedestrians/cyclists!

[M_a_t_t]

You got me thinking. This is what I came up with:

[JulianEdgar]

Originally Posted by M_a_t_t

I also remade the modified GIF. Much easier to look at.



Now for my armchair analysis, let me know how agreeable it is. It appears to be working, atleast better than the stock version. The part on the bumper is angled too sharply and/or because of the spinning wheel and is getting early separation as a result. The lower half shows this because it is flat against the body at the top. The upper half by the tail light seems to be working the best, but possible interference from the rounded trunk edge and wing. Tufts 2 and 3 (from the top) are what I should try to get all the tufts to do.

I meant: I need to see pics of the car being tuft tested in standard and modified forms. I learnt long ago not to assume what the standard tuft patterns would look like!

[JulianEdgar]

Originally Posted by MetroMPG

I've shot video of tuft tests on numerous cars by mounting a small camera on a boom that's attached aft of the area being filmed (obviously to minimize aero interference from the camera rig).

3 examples:


1) 2000 Honda Insight

From thread: MetroMPG's Honda Insight boat tail extension (cardboard) tuft video; ABA test +9.7%

The cord tied between the two booms adds tension to prevent the camera from bouncing.

2) Similar set-up on my 2nd gen 2004 Toyota Prius:

From thread (starting around post #100): The Premier's Limo: 2004 Toyota Prius "winter beater" ecomodding thread

3) And the current car (1990 Miata MX5) - I didn't get a shot of the camera boom itself, but in this case it was a rigid DIY tripod of aluminum tubing, liberally duct taped to the rear & side of the car:





From thread: "MPGiata" modding thread: aiming for 50 MPG with a 1990 Miata. Update: success, 55 MPG


The other two tripod legs are out of the frame.

---


Cameras with wider angle lenses are better because you can use a shorter boom (Prius boom is probably 1/2 the length of the Insight's).


Obviously this approach is only practical/safe if the road you test on is free of obstructions/pedestrians/cyclists!

Yes they look good! I've always been worried by the camera supports influencing flow (even upstream) but it doesn't look like that is happening, does it? Unfortunately I'd be reluctant to run that set-up on public roads (even one glance from a policeman and I'd be in trouble).

[M_a_t_t]

Originally Posted by JulianEdgar

I meant: I need to see pics of the car being tuft tested in standard and modified forms. I learnt long ago not to assume what the standard tuft patterns would look like!

I don't understand. I posted a gif and a link to both sides being tested. Unless you mean it needs to be the same side compared?

I am not trying to test the wheel skirts. Just the separation edges.

[JulianEdgar]

Originally Posted by M_a_t_t

I don't understand. I posted a gif and a link to both sides being tested. Unless you mean it needs to be the same side compared?

Sorry, I assumed that I was meant to be commenting on the flow pattern with all the white panels attached? (ie versus no white panels?)

If all I am meant to be commenting on are the separation edges, then yes, they seem to be working fine. (But I have found with separation edges that measuring pressures is a better way of assessing their effectiveness.)

[M_a_t_t]

I attempted to make a puck for testing, first attempt didn't turn out so well. I suppose it is time to try again.

[JulianEdgar]

Originally Posted by M_a_t_t

I attempted to make a puck for testing, first attempt didn't turn out so well. I suppose it is time to try again.

Not sure I've mentioned this here:



They are commercially available.

[MetroMPG]

Originally Posted by JulianEdgar

Unfortunately I'd be reluctant to run that set-up on public roads (even one glance from a policeman and I'd be in trouble).

Yes, that's always in the back of my mind! Definitely a potential drawback of this approach.


Lucky for me I live near the edge of town, about 30 seconds from some quiet rural roads.