Homebuilt trike aeromodding

[mikesheiman]

https://m.facebook.com/story.php?sto...5&id=507862444

Curious

*) What do you think the Cd (not counting area) is?
*) Where do you think some areas for improvement are / suggested mods

It is a 4 seater hence the back tapering starts pretty late back.

I am especially curious if the lack of a very back roof hurts a lot vs. if the built up pressure above the roof should push itself down fairly quickly and matter little. Not to mention if making a long tapering in back of each front wheel (now wide open to release air pressure under there) would matter much.

[freebeard]

Ack! I clicked a Facebook link in error. Now they will feel entitled to follow me all around Internet.

Can you repost the picture? I only saw it for a split second.

[Grant-53]

I would suggest the roof make a smooth curve to the point just above the rear wheel. See the motorcycles of the Vetter Challenge at Schultz Engineering. Vic Valdes posted 233 mpg at the Mid-Ohio run this year.

[aerohead]

Originally Posted by mikesheiman

https://m.facebook.com/story.php?sto...5&id=507862444

Curious

*) What do you think the Cd (not counting area) is?
*) Where do you think some areas for improvement are / suggested mods

It is a 4 seater hence the back tapering starts pretty late back.

I am especially curious if the lack of a very back roof hurts a lot vs. if the built up pressure above the roof should push itself down fairly quickly and matter little. Not to mention if making a long tapering in back of each front wheel (now wide open to release air pressure under there) would matter much.

It would really help to see a photo shot from above,like from the roof of the house looking straight down on it.
A larger image would help too if you can.

[BLSTIC]

Your Cd is going to be all kinds of horrible. Not counting the fact that it's incomplete and has major gaps & jumps, you need a smoother transition to the rear 'glass', and to taper the gap behind the wheels back to the body. What you have is technically better than an open wheel, but not by nearly as much as it could be

[kach22i]

Originally Posted by mikesheiman

[URL]Not to mention if making a long tapering in back of each front wheel (now wide open to release air pressure under there) would matter much.

1. Front wheel wells need trailing faring's otherwise that will all be drag. You can still vent the trailing edges of the faring.

2. I'm not sure about the open at top venting at the top comment on the Facebook page. I do not see it. I do see a large step where a rear window would normally be. I would make this area a stepped louver at a very gentle slope.

3. The area above the rear wheel does not seem to slope down, looks level. I would slope this slightly down. I would also add a removable or hinged 4-foot section at the tail. This tail is where many of your aerodynamic gains can be realized as it is the size of the hole in the air the vehicle leaves that is important.

I would have done an overlay sketch or mark-up but was unable to right-click and save the image.

As mentioned before we need more images and or drawings to feel confident of our suggestions and to catch everything.

Food for thought images that may inspire, and if they confuse please ask questions.

http://ecomodder.com/forum/showthread.php/stepped-shape-flow-attachment-17590.html


http://www.e46fanatics.com/forum/showthread.php?p=13100365


http://ecomodder.com/forum/showthread.php/aerodynamic-streamlining-template-part-c-9287-61.html


http://ecomodder.com/forum/showthrea...-26678-59.html

[BLSTIC]

If you have a windows machine you have a thing called 'snipping tool' (just search off the start bar). It takes partial screenshots and saves them as .jpg

[kach22i]

Originally Posted by BLSTIC

If you have a windows machine you have a thing called 'snipping tool' (just search off the start bar). It takes partial screenshots and saves them as .jpg

Thanks, I will figure out how to do that later, have other things to do.

I should note though, I went back to the original Facebook link; click on the image and it opens a new screen layout with black areas each side. Click to the far right or far left and there are hidden arrows that take you though a handful of other pictures, including one of a blue scooter.

Looks to be some playful exercises for that rear deck area being looked at.

Ctrl button held down and tapping the "+" symbol twice or so makes the small photos just a little larger. These are painfully small photos to work with.