AERO/HYDRO DYNAMICS.

Good day gentlemen and gals. It seems these rainy Saturday mornings are allowing me to do too much thinking, if you will call it that! Here's my thoughts for the first day of May.

First although not the reason for writing another essay, the Kentucky Derby. I can't imagine anyone would ask such a beautiful animal to step outside in the weather we are having in Kentucky as well the fore-casted weather! The amazing thing to me, those beautiful horses can't wait to get on the track and "do their thing"! Those horses have dreamed of this day although it may not be the perfect day, it's their day regardless of the conditions! It just doesn't seem fair they must perform at their best with so much mud in their face and up their nose.

Now, here's my original though and the reason for logging on to our beloved 429-460.com website.

As I was driving into Owensboro this morning about 0300 hours to get groceries, it was raining at the rate of a tropical storm! Not until the trip home, a bit later and near dawn I noticed the water trail down my rear window as I have noticed many times before. Yep, as to the topic title, was the water informing me of the aerodynamics of my 1992 Thunderbird? As I watched the hydro trail (and watched the road from time to time) it seemed to work it's way toward the middle two (2) feet of the window. However, the passenger side was a bit farther out than the driver side! I thought, is that the weight of the water following the lower side of the car? Highways by design are given a bit of drain to the right on two lane highways. So now I'm thinking ....... hmmmmmm! So when the opportunity presented itself I moved the car to the opposite side of the road. Sure enough, the hydro trail moved toward the driver side of the window. I would have never though a few degrees would effect a small film of water that way.

Now the dilemma of my thoughts. At the point on the window where the hydro trail ceased to move inward on the window, was this an area of no or little down force or air on the window, considering the water wasn't effected by it's own weight?

Another effect on the hydro trail surprised me as well. When I drove through a large puddle of water at highway speed, the splash of water would rise higher than the Thunderbird's side window! In this case, was the "wall of water" directing more air to the rear window and moving the hydro trail further inward of the rear window or just the opposite, creating a vacuum and pulling the water from the rear window?

Just another rainy day though!
Dave.

Doug...

Dave ....what is your background ? ......very interesting read sir

Bruno you are very generous with your praise, thank you. As to my back ground, it's rather dark and filled with perversion! The consequences of "hanging out" with Charlie, Bob and Lem! ...

Dave.

Dave, Where can we send cards and letters

I hear ya with too much time for thinkin!!

I have noticed the same thing on the hood, you can see right where the air(water) stops moving toward the back of the car and at the back of the hood it will travel toward the front of the car. Cowl hood??

Bill

Thank you! I'm finally not alone with my over analization. And no, not like that you pervs. This is the stuff I think about all the time but if I were to try to talk to someone about it all they would do is go "huh?". I completely understand what you are saying, and I'll have to look for that the next time I drive in the rain. But you should know as well as I do that being very analitical is a sickness! But it really does come in handy when working on engines with machine work and clearances yada yada. I like being technical when it comes to cars though.

bb429power wrote:Thank you! I'm finally not alone with my over analization. And no, not like that you pervs. This is the stuff I think about all the time but if I were to try to talk to someone about it all they would do is go "huh?". I completely understand what you are saying, and I'll have to look for that the next time I drive in the rain. But you should know as well as I do that being very analitical is a sickness! But it really does come in handy when working on engines with machine work and clearances yada yada. I like being technical when it comes to cars though.

Some say perversion is a sickness as well, although I haven't realized too much damage ..... yet!

Dave.

dfree383 wrote:Dave, you need a Dog !

As surprising as it may sound, I have had more dogs than I care to remember .... .... After I woke the next morning from a drunken stupor ! A real McCoy or two!

Dave.

i love to read .....

http://www.ahd.tudelft.nl/

http://www.pm-engr.com/cfd/aerodynamics.php

ftp://ftp.rta.nato.int/PubFullText/RTO/MP/RTO-MP-015/$MP-015-25.PDF

Thanks Bruno. At a glance the links appear interesting. I will take time to read those articles and/or browse the websites, as partial payment for your time!

Dave.

"A real McCoy or two!"
Aah yes, the McCoy sisters